Merge github.com:grpc/grpc into bwest

77 files changed, 3177 insertions, 4234 deletions

diff --git a/src/core/lib/channel/channel_stack.c b/src/core/lib/channel/channel_stack.c
index ec973d4e7f..8f08b427fb 100644
--- a/src/core/lib/channel/channel_stack.c
+++ b/src/core/lib/channel/channel_stack.c
@@ -170,7 +170,7 @@ grpc_error *grpc_call_stack_init(
     grpc_exec_ctx *exec_ctx, grpc_channel_stack *channel_stack,
     int initial_refs, grpc_iomgr_cb_func destroy, void *destroy_arg,
     grpc_call_context_element *context, const void *transport_server_data,
-    grpc_slice path, gpr_timespec start_time, gpr_timespec deadline,
+    grpc_mdstr *path, gpr_timespec start_time, gpr_timespec deadline,
     grpc_call_stack *call_stack) {
   grpc_channel_element *channel_elems = CHANNEL_ELEMS_FROM_STACK(channel_stack);
   grpc_call_element_args args;
@@ -288,10 +288,41 @@ grpc_call_stack *grpc_call_stack_from_top_element(grpc_call_element *elem) {
       sizeof(grpc_call_stack)));
 }
 
-void grpc_call_element_signal_error(grpc_exec_ctx *exec_ctx,
-                                    grpc_call_element *elem,
-                                    grpc_error *error) {
-  grpc_transport_stream_op *op = grpc_make_transport_stream_op(NULL);
-  op->cancel_error = error;
+static void destroy_op(grpc_exec_ctx *exec_ctx, void *op, grpc_error *error) {
+  gpr_free(op);
+}
+
+void grpc_call_element_send_cancel(grpc_exec_ctx *exec_ctx,
+                                   grpc_call_element *elem) {
+  grpc_transport_stream_op *op = gpr_malloc(sizeof(*op));
+  memset(op, 0, sizeof(*op));
+  op->cancel_error = GRPC_ERROR_CANCELLED;
+  op->on_complete =
+      grpc_closure_create(destroy_op, op, grpc_schedule_on_exec_ctx);
+  elem->filter->start_transport_stream_op(exec_ctx, elem, op);
+}
+
+void grpc_call_element_send_cancel_with_message(grpc_exec_ctx *exec_ctx,
+                                                grpc_call_element *elem,
+                                                grpc_status_code status,
+                                                grpc_slice *optional_message) {
+  grpc_transport_stream_op *op = gpr_malloc(sizeof(*op));
+  memset(op, 0, sizeof(*op));
+  op->on_complete =
+      grpc_closure_create(destroy_op, op, grpc_schedule_on_exec_ctx);
+  grpc_transport_stream_op_add_cancellation_with_message(exec_ctx, op, status,
+                                                         optional_message);
+  elem->filter->start_transport_stream_op(exec_ctx, elem, op);
+}
+
+void grpc_call_element_send_close_with_message(grpc_exec_ctx *exec_ctx,
+                                               grpc_call_element *elem,
+                                               grpc_status_code status,
+                                               grpc_slice *optional_message) {
+  grpc_transport_stream_op *op = gpr_malloc(sizeof(*op));
+  memset(op, 0, sizeof(*op));
+  op->on_complete =
+      grpc_closure_create(destroy_op, op, grpc_schedule_on_exec_ctx);
+  grpc_transport_stream_op_add_close(exec_ctx, op, status, optional_message);
   elem->filter->start_transport_stream_op(exec_ctx, elem, op);
 }
diff --git a/src/core/lib/channel/channel_stack.h b/src/core/lib/channel/channel_stack.h
index 1cf07d43c2..d9d3a85233 100644
--- a/src/core/lib/channel/channel_stack.h
+++ b/src/core/lib/channel/channel_stack.h
@@ -81,7 +81,7 @@ typedef struct {
   grpc_call_stack *call_stack;
   const void *server_transport_data;
   grpc_call_context_element *context;
-  grpc_slice path;
+  grpc_mdstr *path;
   gpr_timespec start_time;
   gpr_timespec deadline;
 } grpc_call_element_args;
@@ -238,7 +238,7 @@ grpc_error *grpc_call_stack_init(
     grpc_exec_ctx *exec_ctx, grpc_channel_stack *channel_stack,
     int initial_refs, grpc_iomgr_cb_func destroy, void *destroy_arg,
     grpc_call_context_element *context, const void *transport_server_data,
-    grpc_slice path, gpr_timespec start_time, gpr_timespec deadline,
+    grpc_mdstr *path, gpr_timespec start_time, gpr_timespec deadline,
     grpc_call_stack *call_stack);
 /* Set a pollset or a pollset_set for a call stack: must occur before the first
  * op is started */
@@ -299,9 +299,18 @@ grpc_call_stack *grpc_call_stack_from_top_element(grpc_call_element *elem);
 void grpc_call_log_op(char *file, int line, gpr_log_severity severity,
                       grpc_call_element *elem, grpc_transport_stream_op *op);
 
-void grpc_call_element_signal_error(grpc_exec_ctx *exec_ctx,
-                                    grpc_call_element *cur_elem,
-                                    grpc_error *error);
+void grpc_call_element_send_cancel(grpc_exec_ctx *exec_ctx,
+                                   grpc_call_element *cur_elem);
+
+void grpc_call_element_send_cancel_with_message(grpc_exec_ctx *exec_ctx,
+                                                grpc_call_element *cur_elem,
+                                                grpc_status_code status,
+                                                grpc_slice *optional_message);
+
+void grpc_call_element_send_close_with_message(grpc_exec_ctx *exec_ctx,
+                                               grpc_call_element *cur_elem,
+                                               grpc_status_code status,
+                                               grpc_slice *optional_message);
 
 extern int grpc_trace_channel;
 
diff --git a/src/core/lib/channel/compress_filter.c b/src/core/lib/channel/compress_filter.c
index c860d60d88..337c194b79 100644
--- a/src/core/lib/channel/compress_filter.c
+++ b/src/core/lib/channel/compress_filter.c
@@ -45,7 +45,6 @@
 #include "src/core/lib/compression/message_compress.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/static_metadata.h"
 
@@ -81,6 +80,39 @@ typedef struct channel_data {
   uint32_t supported_compression_algorithms;
 } channel_data;
 
+/** For each \a md element from the incoming metadata, filter out the entry for
+ * "grpc-encoding", using its value to populate the call data's
+ * compression_algorithm field. */
+static grpc_mdelem *compression_md_filter(grpc_exec_ctx *exec_ctx,
+                                          void *user_data, grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  channel_data *channeld = elem->channel_data;
+
+  if (md->key == GRPC_MDSTR_GRPC_INTERNAL_ENCODING_REQUEST) {
+    const char *md_c_str = grpc_mdstr_as_c_string(md->value);
+    if (!grpc_compression_algorithm_parse(md_c_str, strlen(md_c_str),
+                                          &calld->compression_algorithm)) {
+      gpr_log(GPR_ERROR,
+              "Invalid compression algorithm: '%s' (unknown). Ignoring.",
+              md_c_str);
+      calld->compression_algorithm = GRPC_COMPRESS_NONE;
+    }
+    if (!GPR_BITGET(channeld->enabled_algorithms_bitset,
+                    calld->compression_algorithm)) {
+      gpr_log(GPR_ERROR,
+              "Invalid compression algorithm: '%s' (previously disabled). "
+              "Ignoring.",
+              md_c_str);
+      calld->compression_algorithm = GRPC_COMPRESS_NONE;
+    }
+    calld->has_compression_algorithm = 1;
+    return NULL;
+  }
+
+  return md;
+}
+
 static int skip_compression(grpc_call_element *elem, uint32_t flags) {
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
@@ -99,65 +131,32 @@ static int skip_compression(grpc_call_element *elem, uint32_t flags) {
 }
 
 /** Filter initial metadata */
-static grpc_error *process_send_initial_metadata(
-    grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
-    grpc_metadata_batch *initial_metadata) GRPC_MUST_USE_RESULT;
-static grpc_error *process_send_initial_metadata(
+static void process_send_initial_metadata(
     grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
     grpc_metadata_batch *initial_metadata) {
-  grpc_error *error;
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
   /* Parse incoming request for compression. If any, it'll be available
    * at calld->compression_algorithm */
-  if (initial_metadata->idx.named.grpc_internal_encoding_request != NULL) {
-    grpc_mdelem md =
-        initial_metadata->idx.named.grpc_internal_encoding_request->md;
-    if (!grpc_compression_algorithm_parse(GRPC_MDVALUE(md),
-                                          &calld->compression_algorithm)) {
-      char *val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
-      gpr_log(GPR_ERROR,
-              "Invalid compression algorithm: '%s' (unknown). Ignoring.", val);
-      gpr_free(val);
-      calld->compression_algorithm = GRPC_COMPRESS_NONE;
-    }
-    if (!GPR_BITGET(channeld->enabled_algorithms_bitset,
-                    calld->compression_algorithm)) {
-      char *val = grpc_slice_to_c_string(GRPC_MDVALUE(md));
-      gpr_log(GPR_ERROR,
-              "Invalid compression algorithm: '%s' (previously disabled). "
-              "Ignoring.",
-              val);
-      gpr_free(val);
-      calld->compression_algorithm = GRPC_COMPRESS_NONE;
-    }
-    calld->has_compression_algorithm = 1;
-
-    grpc_metadata_batch_remove(
-        exec_ctx, initial_metadata,
-        initial_metadata->idx.named.grpc_internal_encoding_request);
-  } else {
+  grpc_metadata_batch_filter(exec_ctx, initial_metadata, compression_md_filter,
+                             elem);
+  if (!calld->has_compression_algorithm) {
     /* If no algorithm was found in the metadata and we aren't
      * exceptionally skipping compression, fall back to the channel
      * default */
     calld->compression_algorithm = channeld->default_compression_algorithm;
     calld->has_compression_algorithm = 1; /* GPR_TRUE */
   }
-
   /* hint compression algorithm */
-  error = grpc_metadata_batch_add_tail(
-      exec_ctx, initial_metadata, &calld->compression_algorithm_storage,
+  grpc_metadata_batch_add_tail(
+      initial_metadata, &calld->compression_algorithm_storage,
       grpc_compression_encoding_mdelem(calld->compression_algorithm));
 
-  if (error != GRPC_ERROR_NONE) return error;
-
   /* convey supported compression algorithms */
-  error = grpc_metadata_batch_add_tail(
-      exec_ctx, initial_metadata, &calld->accept_encoding_storage,
-      GRPC_MDELEM_ACCEPT_ENCODING_FOR_ALGORITHMS(
-          channeld->supported_compression_algorithms));
-
-  return error;
+  grpc_metadata_batch_add_tail(initial_metadata,
+                               &calld->accept_encoding_storage,
+                               GRPC_MDELEM_ACCEPT_ENCODING_FOR_ALGORITHMS(
+                                   channeld->supported_compression_algorithms));
 }
 
 static void continue_send_message(grpc_exec_ctx *exec_ctx,
@@ -248,12 +247,7 @@ static void compress_start_transport_stream_op(grpc_exec_ctx *exec_ctx,
   GPR_TIMER_BEGIN("compress_start_transport_stream_op", 0);
 
   if (op->send_initial_metadata) {
-    grpc_error *error = process_send_initial_metadata(
-        exec_ctx, elem, op->send_initial_metadata);
-    if (error != GRPC_ERROR_NONE) {
-      grpc_transport_stream_op_finish_with_failure(exec_ctx, op, error);
-      return;
-    }
+    process_send_initial_metadata(exec_ctx, elem, op->send_initial_metadata);
   }
   if (op->send_message != NULL &&
       !skip_compression(elem, op->send_message->flags)) {
diff --git a/src/core/lib/channel/deadline_filter.c b/src/core/lib/channel/deadline_filter.c
index bc9a2effc2..a45a4d4b82 100644
--- a/src/core/lib/channel/deadline_filter.c
+++ b/src/core/lib/channel/deadline_filter.c
@@ -56,11 +56,10 @@ static void timer_callback(grpc_exec_ctx* exec_ctx, void* arg,
   deadline_state->timer_pending = false;
   gpr_mu_unlock(&deadline_state->timer_mu);
   if (error != GRPC_ERROR_CANCELLED) {
-    grpc_call_element_signal_error(
-        exec_ctx, elem,
-        grpc_error_set_int(GRPC_ERROR_CREATE("Deadline Exceeded"),
-                           GRPC_ERROR_INT_GRPC_STATUS,
-                           GRPC_STATUS_DEADLINE_EXCEEDED));
+    grpc_slice msg = grpc_slice_from_static_string("Deadline Exceeded");
+    grpc_call_element_send_cancel_with_message(
+        exec_ctx, elem, GRPC_STATUS_DEADLINE_EXCEEDED, &msg);
+    grpc_slice_unref_internal(exec_ctx, msg);
   }
   GRPC_CALL_STACK_UNREF(exec_ctx, deadline_state->call_stack, "deadline_timer");
 }
@@ -197,7 +196,8 @@ void grpc_deadline_state_client_start_transport_stream_op(
     grpc_exec_ctx* exec_ctx, grpc_call_element* elem,
     grpc_transport_stream_op* op) {
   grpc_deadline_state* deadline_state = elem->call_data;
-  if (op->cancel_error != GRPC_ERROR_NONE) {
+  if (op->cancel_error != GRPC_ERROR_NONE ||
+      op->close_error != GRPC_ERROR_NONE) {
     cancel_timer_if_needed(exec_ctx, deadline_state);
   } else {
     // Make sure we know when the call is complete, so that we can cancel
@@ -285,7 +285,8 @@ static void server_start_transport_stream_op(grpc_exec_ctx* exec_ctx,
                                              grpc_call_element* elem,
                                              grpc_transport_stream_op* op) {
   server_call_data* calld = elem->call_data;
-  if (op->cancel_error != GRPC_ERROR_NONE) {
+  if (op->cancel_error != GRPC_ERROR_NONE ||
+      op->close_error != GRPC_ERROR_NONE) {
     cancel_timer_if_needed(exec_ctx, &calld->base.deadline_state);
   } else {
     // If we're receiving initial metadata, we need to get the deadline
diff --git a/src/core/lib/channel/http_client_filter.c b/src/core/lib/channel/http_client_filter.c
index 49a2a980e0..d154450988 100644
--- a/src/core/lib/channel/http_client_filter.c
+++ b/src/core/lib/channel/http_client_filter.c
@@ -38,7 +38,6 @@
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/percent_encoding.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/static_metadata.h"
 #include "src/core/lib/transport/transport_impl.h"
@@ -89,104 +88,77 @@ typedef struct call_data {
 } call_data;
 
 typedef struct channel_data {
-  grpc_mdelem static_scheme;
-  grpc_mdelem user_agent;
+  grpc_mdelem *static_scheme;
+  grpc_mdelem *user_agent;
   size_t max_payload_size_for_get;
 } channel_data;
 
-static grpc_error *client_filter_incoming_metadata(grpc_exec_ctx *exec_ctx,
-                                                   grpc_call_element *elem,
-                                                   grpc_metadata_batch *b) {
-  if (b->idx.named.status != NULL) {
-    if (grpc_mdelem_eq(b->idx.named.status->md, GRPC_MDELEM_STATUS_200)) {
-      grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.status);
-    } else {
-      char *val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.status->md),
-                                  GPR_DUMP_ASCII);
-      char *msg;
-      gpr_asprintf(&msg, "Received http2 header with status: %s", val);
-      grpc_error *e = grpc_error_set_str(
-          grpc_error_set_int(
-              grpc_error_set_str(
-                  GRPC_ERROR_CREATE(
-                      "Received http2 :status header with non-200 OK status"),
-                  GRPC_ERROR_STR_VALUE, val),
-              GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_CANCELLED),
-          GRPC_ERROR_STR_GRPC_MESSAGE, msg);
-      gpr_free(val);
-      gpr_free(msg);
-      return e;
-    }
-  }
-
-  if (b->idx.named.grpc_message != NULL) {
-    grpc_slice pct_decoded_msg = grpc_permissive_percent_decode_slice(
-        GRPC_MDVALUE(b->idx.named.grpc_message->md));
-    if (grpc_slice_is_equivalent(pct_decoded_msg,
-                                 GRPC_MDVALUE(b->idx.named.grpc_message->md))) {
+static grpc_mdelem *client_recv_filter(grpc_exec_ctx *exec_ctx, void *user_data,
+                                       grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
+  if (md == GRPC_MDELEM_STATUS_200) {
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_STATUS) {
+    char *message_string;
+    gpr_asprintf(&message_string, "Received http2 header with status: %s",
+                 grpc_mdstr_as_c_string(md->value));
+    grpc_slice message = grpc_slice_from_copied_string(message_string);
+    gpr_free(message_string);
+    grpc_call_element_send_close_with_message(exec_ctx, elem,
+                                              GRPC_STATUS_CANCELLED, &message);
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_GRPC_MESSAGE) {
+    grpc_slice pct_decoded_msg =
+        grpc_permissive_percent_decode_slice(md->value->slice);
+    if (grpc_slice_is_equivalent(pct_decoded_msg, md->value->slice)) {
       grpc_slice_unref_internal(exec_ctx, pct_decoded_msg);
+      return md;
     } else {
-      grpc_metadata_batch_set_value(exec_ctx, b->idx.named.grpc_message,
-                                    pct_decoded_msg);
+      return grpc_mdelem_from_metadata_strings(
+          exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
+          grpc_mdstr_from_slice(exec_ctx, pct_decoded_msg));
     }
-  }
-
-  if (b->idx.named.content_type != NULL) {
-    if (!grpc_mdelem_eq(b->idx.named.content_type->md,
-                        GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC)) {
-      if (grpc_slice_buf_start_eq(GRPC_MDVALUE(b->idx.named.content_type->md),
-                                  EXPECTED_CONTENT_TYPE,
-                                  EXPECTED_CONTENT_TYPE_LENGTH) &&
-          (GRPC_SLICE_START_PTR(GRPC_MDVALUE(
-               b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] ==
-               '+' ||
-           GRPC_SLICE_START_PTR(GRPC_MDVALUE(
-               b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] ==
-               ';')) {
-        /* Although the C implementation doesn't (currently) generate them,
-           any custom +-suffix is explicitly valid. */
-        /* TODO(klempner): We should consider preallocating common values such
-           as +proto or +json, or at least stashing them if we see them. */
-        /* TODO(klempner): Should we be surfacing this to application code? */
-      } else {
-        /* TODO(klempner): We're currently allowing this, but we shouldn't
-           see it without a proxy so log for now. */
-        char *val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.content_type->md),
-                                    GPR_DUMP_ASCII);
-        gpr_log(GPR_INFO, "Unexpected content-type '%s'", val);
-        gpr_free(val);
-      }
+  } else if (md == GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC) {
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_CONTENT_TYPE) {
+    const char *value_str = grpc_mdstr_as_c_string(md->value);
+    if (strncmp(value_str, EXPECTED_CONTENT_TYPE,
+                EXPECTED_CONTENT_TYPE_LENGTH) == 0 &&
+        (value_str[EXPECTED_CONTENT_TYPE_LENGTH] == '+' ||
+         value_str[EXPECTED_CONTENT_TYPE_LENGTH] == ';')) {
+      /* Although the C implementation doesn't (currently) generate them,
+         any custom +-suffix is explicitly valid. */
+      /* TODO(klempner): We should consider preallocating common values such
+         as +proto or +json, or at least stashing them if we see them. */
+      /* TODO(klempner): Should we be surfacing this to application code? */
+    } else {
+      /* TODO(klempner): We're currently allowing this, but we shouldn't
+         see it without a proxy so log for now. */
+      gpr_log(GPR_INFO, "Unexpected content-type '%s'", value_str);
     }
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.content_type);
+    return NULL;
   }
-
-  return GRPC_ERROR_NONE;
+  return md;
 }
 
 static void hc_on_recv_initial_metadata(grpc_exec_ctx *exec_ctx,
                                         void *user_data, grpc_error *error) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
-  if (error == GRPC_ERROR_NONE) {
-    error = client_filter_incoming_metadata(exec_ctx, elem,
-                                            calld->recv_initial_metadata);
-  } else {
-    GRPC_ERROR_REF(error);
-  }
-  grpc_closure_run(exec_ctx, calld->on_done_recv_initial_metadata, error);
+  grpc_metadata_batch_filter(exec_ctx, calld->recv_initial_metadata,
+                             client_recv_filter, elem);
+  grpc_closure_run(exec_ctx, calld->on_done_recv_initial_metadata,
+                   GRPC_ERROR_REF(error));
 }
 
 static void hc_on_recv_trailing_metadata(grpc_exec_ctx *exec_ctx,
                                          void *user_data, grpc_error *error) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
-  if (error == GRPC_ERROR_NONE) {
-    error = client_filter_incoming_metadata(exec_ctx, elem,
-                                            calld->recv_trailing_metadata);
-  } else {
-    GRPC_ERROR_REF(error);
-  }
-  grpc_closure_run(exec_ctx, calld->on_done_recv_trailing_metadata, error);
+  grpc_metadata_batch_filter(exec_ctx, calld->recv_trailing_metadata,
+                             client_recv_filter, elem);
+  grpc_closure_run(exec_ctx, calld->on_done_recv_trailing_metadata,
+                   GRPC_ERROR_REF(error));
 }
 
 static void hc_on_complete(grpc_exec_ctx *exec_ctx, void *user_data,
@@ -207,12 +179,15 @@ static void send_done(grpc_exec_ctx *exec_ctx, void *elemp, grpc_error *error) {
   calld->post_send->cb(exec_ctx, calld->post_send->cb_arg, error);
 }
 
-static void remove_if_present(grpc_exec_ctx *exec_ctx,
-                              grpc_metadata_batch *batch,
-                              grpc_metadata_batch_callouts_index idx) {
-  if (batch->idx.array[idx] != NULL) {
-    grpc_metadata_batch_remove(exec_ctx, batch, batch->idx.array[idx]);
-  }
+static grpc_mdelem *client_strip_filter(grpc_exec_ctx *exec_ctx,
+                                        void *user_data, grpc_mdelem *md) {
+  /* eat the things we'd like to set ourselves */
+  if (md->key == GRPC_MDSTR_METHOD) return NULL;
+  if (md->key == GRPC_MDSTR_SCHEME) return NULL;
+  if (md->key == GRPC_MDSTR_TE) return NULL;
+  if (md->key == GRPC_MDSTR_CONTENT_TYPE) return NULL;
+  if (md->key == GRPC_MDSTR_USER_AGENT) return NULL;
+  return md;
 }
 
 static void continue_send_message(grpc_exec_ctx *exec_ctx,
@@ -251,20 +226,18 @@ static void got_slice(grpc_exec_ctx *exec_ctx, void *elemp, grpc_error *error) {
   }
 }
 
-static grpc_error *hc_mutate_op(grpc_exec_ctx *exec_ctx,
-                                grpc_call_element *elem,
-                                grpc_transport_stream_op *op) {
+static void hc_mutate_op(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                         grpc_transport_stream_op *op) {
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
-  grpc_error *error;
 
   if (op->send_initial_metadata != NULL) {
     /* Decide which HTTP VERB to use. We use GET if the request is marked
     cacheable, and the operation contains both initial metadata and send
     message, and the payload is below the size threshold, and all the data
     for this request is immediately available. */
-    grpc_mdelem method = GRPC_MDELEM_METHOD_POST;
+    grpc_mdelem *method = GRPC_MDELEM_METHOD_POST;
     if ((op->send_initial_metadata_flags &
          GRPC_INITIAL_METADATA_CACHEABLE_REQUEST) &&
         op->send_message != NULL &&
@@ -281,7 +254,7 @@ static grpc_error *hc_mutate_op(grpc_exec_ctx *exec_ctx,
     }
 
     /* Attempt to read the data from send_message and create a header field. */
-    if (grpc_mdelem_eq(method, GRPC_MDELEM_METHOD_GET)) {
+    if (method == GRPC_MDELEM_METHOD_GET) {
       /* allocate memory to hold the entire payload */
       calld->payload_bytes = gpr_malloc(op->send_message->length);
 
@@ -294,14 +267,12 @@ static grpc_error *hc_mutate_op(grpc_exec_ctx *exec_ctx,
       if (calld->send_message_blocked == false) {
         /* when all the send_message data is available, then create a MDELEM and
         append to headers */
-        grpc_mdelem payload_bin = grpc_mdelem_from_slices(
+        grpc_mdelem *payload_bin = grpc_mdelem_from_metadata_strings(
             exec_ctx, GRPC_MDSTR_GRPC_PAYLOAD_BIN,
-            grpc_slice_from_copied_buffer((const char *)calld->payload_bytes,
-                                          op->send_message->length));
-        error =
-            grpc_metadata_batch_add_tail(exec_ctx, op->send_initial_metadata,
-                                         &calld->payload_bin, payload_bin);
-        if (error != GRPC_ERROR_NONE) return error;
+            grpc_mdstr_from_buffer(calld->payload_bytes,
+                                   op->send_message->length));
+        grpc_metadata_batch_add_tail(op->send_initial_metadata,
+                                     &calld->payload_bin, payload_bin);
         calld->on_complete = op->on_complete;
         op->on_complete = &calld->hc_on_complete;
         op->send_message = NULL;
@@ -314,35 +285,21 @@ static grpc_error *hc_mutate_op(grpc_exec_ctx *exec_ctx,
       }
     }
 
-    remove_if_present(exec_ctx, op->send_initial_metadata, GRPC_BATCH_METHOD);
-    remove_if_present(exec_ctx, op->send_initial_metadata, GRPC_BATCH_SCHEME);
-    remove_if_present(exec_ctx, op->send_initial_metadata, GRPC_BATCH_TE);
-    remove_if_present(exec_ctx, op->send_initial_metadata,
-                      GRPC_BATCH_CONTENT_TYPE);
-    remove_if_present(exec_ctx, op->send_initial_metadata,
-                      GRPC_BATCH_USER_AGENT);
-
+    grpc_metadata_batch_filter(exec_ctx, op->send_initial_metadata,
+                               client_strip_filter, elem);
     /* Send : prefixed headers, which have to be before any application
        layer headers. */
-    error = grpc_metadata_batch_add_head(exec_ctx, op->send_initial_metadata,
-                                         &calld->method, method);
-    if (error != GRPC_ERROR_NONE) return error;
-    error =
-        grpc_metadata_batch_add_head(exec_ctx, op->send_initial_metadata,
-                                     &calld->scheme, channeld->static_scheme);
-    if (error != GRPC_ERROR_NONE) return error;
-    error = grpc_metadata_batch_add_tail(exec_ctx, op->send_initial_metadata,
-                                         &calld->te_trailers,
-                                         GRPC_MDELEM_TE_TRAILERS);
-    if (error != GRPC_ERROR_NONE) return error;
-    error = grpc_metadata_batch_add_tail(
-        exec_ctx, op->send_initial_metadata, &calld->content_type,
+    grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->method,
+                                 method);
+    grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->scheme,
+                                 channeld->static_scheme);
+    grpc_metadata_batch_add_tail(op->send_initial_metadata, &calld->te_trailers,
+                                 GRPC_MDELEM_TE_TRAILERS);
+    grpc_metadata_batch_add_tail(
+        op->send_initial_metadata, &calld->content_type,
         GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC);
-    if (error != GRPC_ERROR_NONE) return error;
-    error = grpc_metadata_batch_add_tail(exec_ctx, op->send_initial_metadata,
-                                         &calld->user_agent,
-                                         GRPC_MDELEM_REF(channeld->user_agent));
-    if (error != GRPC_ERROR_NONE) return error;
+    grpc_metadata_batch_add_tail(op->send_initial_metadata, &calld->user_agent,
+                                 GRPC_MDELEM_REF(channeld->user_agent));
   }
 
   if (op->recv_initial_metadata != NULL) {
@@ -358,8 +315,6 @@ static grpc_error *hc_mutate_op(grpc_exec_ctx *exec_ctx,
     calld->on_done_recv_trailing_metadata = op->on_complete;
     op->on_complete = &calld->hc_on_recv_trailing_metadata;
   }
-
-  return GRPC_ERROR_NONE;
 }
 
 static void hc_start_transport_op(grpc_exec_ctx *exec_ctx,
@@ -367,20 +322,15 @@ static void hc_start_transport_op(grpc_exec_ctx *exec_ctx,
                                   grpc_transport_stream_op *op) {
   GPR_TIMER_BEGIN("hc_start_transport_op", 0);
   GRPC_CALL_LOG_OP(GPR_INFO, elem, op);
-  grpc_error *error = hc_mutate_op(exec_ctx, elem, op);
-  if (error != GRPC_ERROR_NONE) {
-    grpc_transport_stream_op_finish_with_failure(exec_ctx, op, error);
+  hc_mutate_op(exec_ctx, elem, op);
+  GPR_TIMER_END("hc_start_transport_op", 0);
+  call_data *calld = elem->call_data;
+  if (op->send_message != NULL && calld->send_message_blocked) {
+    /* Don't forward the op. send_message contains slices that aren't ready
+    yet. The call will be forwarded by the op_complete of slice read call. */
   } else {
-    call_data *calld = elem->call_data;
-    if (op->send_message != NULL && calld->send_message_blocked) {
-      /* Don't forward the op. send_message contains slices that aren't ready
-      yet. The call will be forwarded by the op_complete of slice read call.
-      */
-    } else {
-      grpc_call_next_op(exec_ctx, elem, op);
-    }
+    grpc_call_next_op(exec_ctx, elem, op);
   }
-  GPR_TIMER_END("hc_start_transport_op", 0);
 }
 
 /* Constructor for call_data */
@@ -417,18 +367,18 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   grpc_slice_buffer_destroy_internal(exec_ctx, &calld->slices);
 }
 
-static grpc_mdelem scheme_from_args(const grpc_channel_args *args) {
+static grpc_mdelem *scheme_from_args(const grpc_channel_args *args) {
   unsigned i;
   size_t j;
-  grpc_mdelem valid_schemes[] = {GRPC_MDELEM_SCHEME_HTTP,
-                                 GRPC_MDELEM_SCHEME_HTTPS};
+  grpc_mdelem *valid_schemes[] = {GRPC_MDELEM_SCHEME_HTTP,
+                                  GRPC_MDELEM_SCHEME_HTTPS};
   if (args != NULL) {
     for (i = 0; i < args->num_args; ++i) {
       if (args->args[i].type == GRPC_ARG_STRING &&
           strcmp(args->args[i].key, GRPC_ARG_HTTP2_SCHEME) == 0) {
         for (j = 0; j < GPR_ARRAY_SIZE(valid_schemes); j++) {
-          if (0 == grpc_slice_str_cmp(GRPC_MDVALUE(valid_schemes[j]),
-                                      args->args[i].value.string)) {
+          if (0 == strcmp(grpc_mdstr_as_c_string(valid_schemes[j]->value),
+                          args->args[i].value.string)) {
             return valid_schemes[j];
           }
         }
@@ -454,13 +404,13 @@ static size_t max_payload_size_from_args(const grpc_channel_args *args) {
   return kMaxPayloadSizeForGet;
 }
 
-static grpc_slice user_agent_from_args(const grpc_channel_args *args,
-                                       const char *transport_name) {
+static grpc_mdstr *user_agent_from_args(const grpc_channel_args *args,
+                                        const char *transport_name) {
   gpr_strvec v;
   size_t i;
   int is_first = 1;
   char *tmp;
-  grpc_slice result;
+  grpc_mdstr *result;
 
   gpr_strvec_init(&v);
 
@@ -498,7 +448,7 @@ static grpc_slice user_agent_from_args(const grpc_channel_args *args,
 
   tmp = gpr_strvec_flatten(&v, NULL);
   gpr_strvec_destroy(&v);
-  result = grpc_slice_intern(grpc_slice_from_static_string(tmp));
+  result = grpc_mdstr_from_string(tmp);
   gpr_free(tmp);
 
   return result;
@@ -514,7 +464,7 @@ static grpc_error *init_channel_elem(grpc_exec_ctx *exec_ctx,
   chand->static_scheme = scheme_from_args(args->channel_args);
   chand->max_payload_size_for_get =
       max_payload_size_from_args(args->channel_args);
-  chand->user_agent = grpc_mdelem_from_slices(
+  chand->user_agent = grpc_mdelem_from_metadata_strings(
       exec_ctx, GRPC_MDSTR_USER_AGENT,
       user_agent_from_args(args->channel_args,
                            args->optional_transport->vtable->name));
diff --git a/src/core/lib/channel/http_server_filter.c b/src/core/lib/channel/http_server_filter.c
index 3f992977c0..f508231238 100644
--- a/src/core/lib/channel/http_server_filter.c
+++ b/src/core/lib/channel/http_server_filter.c
@@ -39,7 +39,6 @@
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/percent_encoding.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/transport/static_metadata.h"
 
 #define EXPECTED_CONTENT_TYPE "application/grpc"
@@ -48,13 +47,18 @@
 extern int grpc_http_trace;
 
 typedef struct call_data {
+  uint8_t seen_path;
+  uint8_t seen_method;
+  uint8_t sent_status;
+  uint8_t seen_scheme;
+  uint8_t seen_te_trailers;
+  uint8_t seen_authority;
+  uint8_t seen_payload_bin;
   grpc_linked_mdelem status;
   grpc_linked_mdelem content_type;
 
-  /* did this request come with payload-bin */
-  bool seen_payload_bin;
   /* flag to ensure payload_bin is delivered only once */
-  bool payload_bin_delivered;
+  uint8_t payload_bin_delivered;
 
   grpc_metadata_batch *recv_initial_metadata;
   bool *recv_idempotent_request;
@@ -79,152 +83,109 @@ typedef struct call_data {
 
 typedef struct channel_data { uint8_t unused; } channel_data;
 
-static grpc_error *server_filter_outgoing_metadata(grpc_exec_ctx *exec_ctx,
-                                                   grpc_call_element *elem,
-                                                   grpc_metadata_batch *b) {
-  if (b->idx.named.grpc_message != NULL) {
+static grpc_mdelem *server_filter_outgoing_metadata(grpc_exec_ctx *exec_ctx,
+                                                    void *user_data,
+                                                    grpc_mdelem *md) {
+  if (md->key == GRPC_MDSTR_GRPC_MESSAGE) {
     grpc_slice pct_encoded_msg = grpc_percent_encode_slice(
-        GRPC_MDVALUE(b->idx.named.grpc_message->md),
-        grpc_compatible_percent_encoding_unreserved_bytes);
-    if (grpc_slice_is_equivalent(pct_encoded_msg,
-                                 GRPC_MDVALUE(b->idx.named.grpc_message->md))) {
+        md->value->slice, grpc_compatible_percent_encoding_unreserved_bytes);
+    if (grpc_slice_is_equivalent(pct_encoded_msg, md->value->slice)) {
       grpc_slice_unref_internal(exec_ctx, pct_encoded_msg);
+      return md;
     } else {
-      grpc_metadata_batch_set_value(exec_ctx, b->idx.named.grpc_message,
-                                    pct_encoded_msg);
+      return grpc_mdelem_from_metadata_strings(
+          exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
+          grpc_mdstr_from_slice(exec_ctx, pct_encoded_msg));
     }
+  } else {
+    return md;
   }
-  return GRPC_ERROR_NONE;
-}
-
-static void add_error(const char *error_name, grpc_error **cumulative,
-                      grpc_error *new) {
-  if (new == GRPC_ERROR_NONE) return;
-  if (*cumulative == GRPC_ERROR_NONE) {
-    *cumulative = GRPC_ERROR_CREATE(error_name);
-  }
-  *cumulative = grpc_error_add_child(*cumulative, new);
 }
 
-static grpc_error *server_filter_incoming_metadata(grpc_exec_ctx *exec_ctx,
-                                                   grpc_call_element *elem,
-                                                   grpc_metadata_batch *b) {
+static grpc_mdelem *server_filter(grpc_exec_ctx *exec_ctx, void *user_data,
+                                  grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
-  grpc_error *error = GRPC_ERROR_NONE;
-  static const char *error_name = "Failed processing incoming headers";
 
-  if (b->idx.named.method != NULL) {
-    if (grpc_mdelem_eq(b->idx.named.method->md, GRPC_MDELEM_METHOD_POST)) {
+  /* Check if it is one of the headers we care about. */
+  if (md == GRPC_MDELEM_TE_TRAILERS || md == GRPC_MDELEM_METHOD_POST ||
+      md == GRPC_MDELEM_METHOD_PUT || md == GRPC_MDELEM_METHOD_GET ||
+      md == GRPC_MDELEM_SCHEME_HTTP || md == GRPC_MDELEM_SCHEME_HTTPS ||
+      md == GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC) {
+    /* swallow it */
+    if (md == GRPC_MDELEM_METHOD_POST) {
+      calld->seen_method = 1;
       *calld->recv_idempotent_request = false;
       *calld->recv_cacheable_request = false;
-    } else if (grpc_mdelem_eq(b->idx.named.method->md,
-                              GRPC_MDELEM_METHOD_PUT)) {
+    } else if (md == GRPC_MDELEM_METHOD_PUT) {
+      calld->seen_method = 1;
       *calld->recv_idempotent_request = true;
-    } else if (grpc_mdelem_eq(b->idx.named.method->md,
-                              GRPC_MDELEM_METHOD_GET)) {
+    } else if (md == GRPC_MDELEM_METHOD_GET) {
+      calld->seen_method = 1;
       *calld->recv_cacheable_request = true;
-    } else {
-      add_error(error_name, &error,
-                grpc_attach_md_to_error(GRPC_ERROR_CREATE("Bad header"),
-                                        b->idx.named.method->md));
-    }
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.method);
-  } else {
-    add_error(error_name, &error,
-              grpc_error_set_str(GRPC_ERROR_CREATE("Missing header"),
-                                 GRPC_ERROR_STR_KEY, ":method"));
-  }
-
-  if (b->idx.named.te != NULL) {
-    if (!grpc_mdelem_eq(b->idx.named.te->md, GRPC_MDELEM_TE_TRAILERS)) {
-      add_error(error_name, &error,
-                grpc_attach_md_to_error(GRPC_ERROR_CREATE("Bad header"),
-                                        b->idx.named.te->md));
+    } else if (md->key == GRPC_MDSTR_SCHEME) {
+      calld->seen_scheme = 1;
+    } else if (md == GRPC_MDELEM_TE_TRAILERS) {
+      calld->seen_te_trailers = 1;
     }
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.te);
-  } else {
-    add_error(error_name, &error,
-              grpc_error_set_str(GRPC_ERROR_CREATE("Missing header"),
-                                 GRPC_ERROR_STR_KEY, "te"));
-  }
-
-  if (b->idx.named.scheme != NULL) {
-    if (!grpc_mdelem_eq(b->idx.named.scheme->md, GRPC_MDELEM_SCHEME_HTTP) &&
-        !grpc_mdelem_eq(b->idx.named.scheme->md, GRPC_MDELEM_SCHEME_HTTPS) &&
-        !grpc_mdelem_eq(b->idx.named.scheme->md, GRPC_MDELEM_SCHEME_GRPC)) {
-      add_error(error_name, &error,
-                grpc_attach_md_to_error(GRPC_ERROR_CREATE("Bad header"),
-                                        b->idx.named.scheme->md));
+    /* TODO(klempner): Track that we've seen all the headers we should
+       require */
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_CONTENT_TYPE) {
+    const char *value_str = grpc_mdstr_as_c_string(md->value);
+    if (strncmp(value_str, EXPECTED_CONTENT_TYPE,
+                EXPECTED_CONTENT_TYPE_LENGTH) == 0 &&
+        (value_str[EXPECTED_CONTENT_TYPE_LENGTH] == '+' ||
+         value_str[EXPECTED_CONTENT_TYPE_LENGTH] == ';')) {
+      /* Although the C implementation doesn't (currently) generate them,
+         any custom +-suffix is explicitly valid. */
+      /* TODO(klempner): We should consider preallocating common values such
+         as +proto or +json, or at least stashing them if we see them. */
+      /* TODO(klempner): Should we be surfacing this to application code? */
+    } else {
+      /* TODO(klempner): We're currently allowing this, but we shouldn't
+         see it without a proxy so log for now. */
+      gpr_log(GPR_INFO, "Unexpected content-type '%s'", value_str);
     }
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.scheme);
-  } else {
-    add_error(error_name, &error,
-              grpc_error_set_str(GRPC_ERROR_CREATE("Missing header"),
-                                 GRPC_ERROR_STR_KEY, ":scheme"));
-  }
-
-  if (b->idx.named.content_type != NULL) {
-    if (!grpc_mdelem_eq(b->idx.named.content_type->md,
-                        GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC)) {
-      if (grpc_slice_buf_start_eq(GRPC_MDVALUE(b->idx.named.content_type->md),
-                                  EXPECTED_CONTENT_TYPE,
-                                  EXPECTED_CONTENT_TYPE_LENGTH) &&
-          (GRPC_SLICE_START_PTR(GRPC_MDVALUE(
-               b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] ==
-               '+' ||
-           GRPC_SLICE_START_PTR(GRPC_MDVALUE(
-               b->idx.named.content_type->md))[EXPECTED_CONTENT_TYPE_LENGTH] ==
-               ';')) {
-        /* Although the C implementation doesn't (currently) generate them,
-           any custom +-suffix is explicitly valid. */
-        /* TODO(klempner): We should consider preallocating common values such
-           as +proto or +json, or at least stashing them if we see them. */
-        /* TODO(klempner): Should we be surfacing this to application code? */
-      } else {
-        /* TODO(klempner): We're currently allowing this, but we shouldn't
-           see it without a proxy so log for now. */
-        char *val = grpc_dump_slice(GRPC_MDVALUE(b->idx.named.content_type->md),
-                                    GPR_DUMP_ASCII);
-        gpr_log(GPR_INFO, "Unexpected content-type '%s'", val);
-        gpr_free(val);
-      }
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_TE || md->key == GRPC_MDSTR_METHOD ||
+             md->key == GRPC_MDSTR_SCHEME) {
+    gpr_log(GPR_ERROR, "Invalid %s: header: '%s'",
+            grpc_mdstr_as_c_string(md->key), grpc_mdstr_as_c_string(md->value));
+    /* swallow it and error everything out. */
+    /* TODO(klempner): We ought to generate more descriptive error messages
+       on the wire here. */
+    grpc_call_element_send_cancel(exec_ctx, elem);
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_PATH) {
+    if (calld->seen_path) {
+      gpr_log(GPR_ERROR, "Received :path twice");
+      return NULL;
     }
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.content_type);
-  }
-
-  if (b->idx.named.path == NULL) {
-    add_error(error_name, &error,
-              grpc_error_set_str(GRPC_ERROR_CREATE("Missing header"),
-                                 GRPC_ERROR_STR_KEY, ":path"));
-  }
-
-  if (b->idx.named.host != NULL) {
-    add_error(
-        error_name, &error,
-        grpc_metadata_batch_substitute(
-            exec_ctx, b, b->idx.named.host,
-            grpc_mdelem_from_slices(
-                exec_ctx, GRPC_MDSTR_AUTHORITY,
-                grpc_slice_ref_internal(GRPC_MDVALUE(b->idx.named.host->md)))));
-  }
-
-  if (b->idx.named.authority == NULL) {
-    add_error(error_name, &error,
-              grpc_error_set_str(GRPC_ERROR_CREATE("Missing header"),
-                                 GRPC_ERROR_STR_KEY, ":authority"));
-  }
-
-  if (b->idx.named.grpc_payload_bin != NULL) {
-    calld->seen_payload_bin = true;
+    calld->seen_path = 1;
+    return md;
+  } else if (md->key == GRPC_MDSTR_AUTHORITY) {
+    calld->seen_authority = 1;
+    return md;
+  } else if (md->key == GRPC_MDSTR_HOST) {
+    /* translate host to :authority since :authority may be
+       omitted */
+    grpc_mdelem *authority = grpc_mdelem_from_metadata_strings(
+        exec_ctx, GRPC_MDSTR_AUTHORITY, GRPC_MDSTR_REF(md->value));
+    calld->seen_authority = 1;
+    return authority;
+  } else if (md->key == GRPC_MDSTR_GRPC_PAYLOAD_BIN) {
+    /* Retrieve the payload from the value of the 'grpc-internal-payload-bin'
+       header field */
+    calld->seen_payload_bin = 1;
     grpc_slice_buffer_add(&calld->read_slice_buffer,
-                          grpc_slice_ref_internal(
-                              GRPC_MDVALUE(b->idx.named.grpc_payload_bin->md)));
+                          grpc_slice_ref_internal(md->value->slice));
     grpc_slice_buffer_stream_init(&calld->read_stream,
                                   &calld->read_slice_buffer, 0);
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.grpc_payload_bin);
+    return NULL;
+  } else {
+    return md;
   }
-
-  return error;
 }
 
 static void hs_on_recv(grpc_exec_ctx *exec_ctx, void *user_data,
@@ -232,12 +193,49 @@ static void hs_on_recv(grpc_exec_ctx *exec_ctx, void *user_data,
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
   if (err == GRPC_ERROR_NONE) {
-    err = server_filter_incoming_metadata(exec_ctx, elem,
-                                          calld->recv_initial_metadata);
+    grpc_metadata_batch_filter(exec_ctx, calld->recv_initial_metadata,
+                               server_filter, elem);
+    /* Have we seen the required http2 transport headers?
+       (:method, :scheme, content-type, with :path and :authority covered
+       at the channel level right now) */
+    if (calld->seen_method && calld->seen_scheme && calld->seen_te_trailers &&
+        calld->seen_path && calld->seen_authority) {
+      /* do nothing */
+    } else {
+      err = GRPC_ERROR_CREATE("Bad incoming HTTP headers");
+      if (!calld->seen_path) {
+        err = grpc_error_add_child(err,
+                                   GRPC_ERROR_CREATE("Missing :path header"));
+      }
+      if (!calld->seen_authority) {
+        err = grpc_error_add_child(
+            err, GRPC_ERROR_CREATE("Missing :authority header"));
+      }
+      if (!calld->seen_method) {
+        err = grpc_error_add_child(err,
+                                   GRPC_ERROR_CREATE("Missing :method header"));
+      }
+      if (!calld->seen_scheme) {
+        err = grpc_error_add_child(err,
+                                   GRPC_ERROR_CREATE("Missing :scheme header"));
+      }
+      if (!calld->seen_te_trailers) {
+        err = grpc_error_add_child(
+            err, GRPC_ERROR_CREATE("Missing te: trailers header"));
+      }
+      /* Error this call out */
+      if (grpc_http_trace) {
+        const char *error_str = grpc_error_string(err);
+        gpr_log(GPR_ERROR, "Invalid http2 headers: %s", error_str);
+        grpc_error_free_string(error_str);
+      }
+      grpc_call_element_send_cancel(exec_ctx, elem);
+    }
   } else {
     GRPC_ERROR_REF(err);
   }
-  grpc_closure_run(exec_ctx, calld->on_done_recv, err);
+  calld->on_done_recv->cb(exec_ctx, calld->on_done_recv->cb_arg, err);
+  GRPC_ERROR_UNREF(err);
 }
 
 static void hs_on_complete(grpc_exec_ctx *exec_ctx, void *user_data,
@@ -275,23 +273,13 @@ static void hs_mutate_op(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   /* grab pointers to our data from the call element */
   call_data *calld = elem->call_data;
 
-  if (op->send_initial_metadata != NULL) {
-    grpc_error *error = GRPC_ERROR_NONE;
-    static const char *error_name = "Failed sending initial metadata";
-    add_error(error_name, &error, grpc_metadata_batch_add_head(
-                                      exec_ctx, op->send_initial_metadata,
-                                      &calld->status, GRPC_MDELEM_STATUS_200));
-    add_error(error_name, &error,
-              grpc_metadata_batch_add_tail(
-                  exec_ctx, op->send_initial_metadata, &calld->content_type,
-                  GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC));
-    add_error(error_name, &error,
-              server_filter_outgoing_metadata(exec_ctx, elem,
-                                              op->send_initial_metadata));
-    if (error != GRPC_ERROR_NONE) {
-      grpc_transport_stream_op_finish_with_failure(exec_ctx, op, error);
-      return;
-    }
+  if (op->send_initial_metadata != NULL && !calld->sent_status) {
+    calld->sent_status = 1;
+    grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->status,
+                                 GRPC_MDELEM_STATUS_200);
+    grpc_metadata_batch_add_tail(
+        op->send_initial_metadata, &calld->content_type,
+        GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC);
   }
 
   if (op->recv_initial_metadata) {
@@ -318,12 +306,8 @@ static void hs_mutate_op(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
   }
 
   if (op->send_trailing_metadata) {
-    grpc_error *error = server_filter_outgoing_metadata(
-        exec_ctx, elem, op->send_trailing_metadata);
-    if (error != GRPC_ERROR_NONE) {
-      grpc_transport_stream_op_finish_with_failure(exec_ctx, op, error);
-      return;
-    }
+    grpc_metadata_batch_filter(exec_ctx, op->send_trailing_metadata,
+                               server_filter_outgoing_metadata, elem);
   }
 }
 
diff --git a/src/core/lib/channel/message_size_filter.c b/src/core/lib/channel/message_size_filter.c
index d9862c5252..862090b371 100644
--- a/src/core/lib/channel/message_size_filter.c
+++ b/src/core/lib/channel/message_size_filter.c
@@ -58,7 +58,7 @@ static void message_size_limits_free(grpc_exec_ctx* exec_ctx, void* value) {
   gpr_free(value);
 }
 
-static const grpc_slice_hash_table_vtable message_size_limits_vtable = {
+static const grpc_mdstr_hash_table_vtable message_size_limits_vtable = {
     message_size_limits_free, message_size_limits_copy};
 
 static void* message_size_limits_create_from_json(const grpc_json* json) {
@@ -101,7 +101,7 @@ typedef struct channel_data {
   int max_send_size;
   int max_recv_size;
   // Maps path names to message_size_limits structs.
-  grpc_slice_hash_table* method_limit_table;
+  grpc_mdstr_hash_table* method_limit_table;
 } channel_data;
 
 // Callback invoked when we receive a message.  Here we check the max
@@ -142,12 +142,10 @@ static void start_transport_stream_op(grpc_exec_ctx* exec_ctx,
     char* message_string;
     gpr_asprintf(&message_string, "Sent message larger than max (%u vs. %d)",
                  op->send_message->length, calld->max_send_size);
-    grpc_transport_stream_op_finish_with_failure(
-        exec_ctx, op, grpc_error_set_int(GRPC_ERROR_CREATE(message_string),
-                                         GRPC_ERROR_INT_GRPC_STATUS,
-                                         GRPC_STATUS_INVALID_ARGUMENT));
+    grpc_slice message = grpc_slice_from_copied_string(message_string);
     gpr_free(message_string);
-    return;
+    grpc_call_element_send_close_with_message(
+        exec_ctx, elem, GRPC_STATUS_INVALID_ARGUMENT, &message);
   }
   // Inject callback for receiving a message.
   if (op->recv_message_ready != NULL) {
@@ -245,7 +243,7 @@ static grpc_error* init_channel_elem(grpc_exec_ctx* exec_ctx,
 static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
                                  grpc_channel_element* elem) {
   channel_data* chand = elem->channel_data;
-  grpc_slice_hash_table_unref(exec_ctx, chand->method_limit_table);
+  grpc_mdstr_hash_table_unref(exec_ctx, chand->method_limit_table);
 }
 
 const grpc_channel_filter grpc_message_size_filter = {
diff --git a/src/core/lib/compression/algorithm_metadata.h b/src/core/lib/compression/algorithm_metadata.h
index 58dfe628b4..1f9cc15f23 100644
--- a/src/core/lib/compression/algorithm_metadata.h
+++ b/src/core/lib/compression/algorithm_metadata.h
@@ -38,16 +38,16 @@
 #include "src/core/lib/transport/metadata.h"
 
 /** Return compression algorithm based metadata value */
-grpc_slice grpc_compression_algorithm_slice(
+grpc_mdstr *grpc_compression_algorithm_mdstr(
     grpc_compression_algorithm algorithm);
 
 /** Return compression algorithm based metadata element (grpc-encoding: xxx) */
-grpc_mdelem grpc_compression_encoding_mdelem(
+grpc_mdelem *grpc_compression_encoding_mdelem(
     grpc_compression_algorithm algorithm);
 
 /** Find compression algorithm based on passed in mdstr - returns
  * GRPC_COMPRESS_ALGORITHM_COUNT on failure */
-grpc_compression_algorithm grpc_compression_algorithm_from_slice(
-    grpc_slice str);
+grpc_compression_algorithm grpc_compression_algorithm_from_mdstr(
+    grpc_mdstr *str);
 
 #endif /* GRPC_CORE_LIB_COMPRESSION_ALGORITHM_METADATA_H */
diff --git a/src/core/lib/compression/compression.c b/src/core/lib/compression/compression.c
index ce4f597af5..54efb5e855 100644
--- a/src/core/lib/compression/compression.c
+++ b/src/core/lib/compression/compression.c
@@ -41,24 +41,30 @@
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/transport/static_metadata.h"
 
-int grpc_compression_algorithm_parse(grpc_slice name,
+int grpc_compression_algorithm_parse(const char *name, size_t name_length,
                                      grpc_compression_algorithm *algorithm) {
   /* we use strncmp not only because it's safer (even though in this case it
    * doesn't matter, given that we are comparing against string literals, but
    * because this way we needn't have "name" nil-terminated (useful for slice
    * data, for example) */
-  if (grpc_slice_eq(name, GRPC_MDSTR_IDENTITY)) {
+  GRPC_API_TRACE(
+      "grpc_compression_algorithm_parse("
+      "name=%*.*s, name_length=%lu, algorithm=%p)",
+      5, ((int)name_length, (int)name_length, name, (unsigned long)name_length,
+          algorithm));
+  if (name_length == 0) {
+    return 0;
+  }
+  if (strncmp(name, "identity", name_length) == 0) {
     *algorithm = GRPC_COMPRESS_NONE;
-    return 1;
-  } else if (grpc_slice_eq(name, GRPC_MDSTR_GZIP)) {
+  } else if (strncmp(name, "gzip", name_length) == 0) {
     *algorithm = GRPC_COMPRESS_GZIP;
-    return 1;
-  } else if (grpc_slice_eq(name, GRPC_MDSTR_DEFLATE)) {
+  } else if (strncmp(name, "deflate", name_length) == 0) {
     *algorithm = GRPC_COMPRESS_DEFLATE;
-    return 1;
   } else {
     return 0;
   }
+  return 1;
 }
 
 int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm,
@@ -81,15 +87,15 @@ int grpc_compression_algorithm_name(grpc_compression_algorithm algorithm,
   return 0;
 }
 
-grpc_compression_algorithm grpc_compression_algorithm_from_slice(
-    grpc_slice str) {
-  if (grpc_slice_eq(str, GRPC_MDSTR_IDENTITY)) return GRPC_COMPRESS_NONE;
-  if (grpc_slice_eq(str, GRPC_MDSTR_DEFLATE)) return GRPC_COMPRESS_DEFLATE;
-  if (grpc_slice_eq(str, GRPC_MDSTR_GZIP)) return GRPC_COMPRESS_GZIP;
+grpc_compression_algorithm grpc_compression_algorithm_from_mdstr(
+    grpc_mdstr *str) {
+  if (str == GRPC_MDSTR_IDENTITY) return GRPC_COMPRESS_NONE;
+  if (str == GRPC_MDSTR_DEFLATE) return GRPC_COMPRESS_DEFLATE;
+  if (str == GRPC_MDSTR_GZIP) return GRPC_COMPRESS_GZIP;
   return GRPC_COMPRESS_ALGORITHMS_COUNT;
 }
 
-grpc_slice grpc_compression_algorithm_slice(
+grpc_mdstr *grpc_compression_algorithm_mdstr(
     grpc_compression_algorithm algorithm) {
   switch (algorithm) {
     case GRPC_COMPRESS_NONE:
@@ -99,12 +105,12 @@ grpc_slice grpc_compression_algorithm_slice(
     case GRPC_COMPRESS_GZIP:
       return GRPC_MDSTR_GZIP;
     case GRPC_COMPRESS_ALGORITHMS_COUNT:
-      return grpc_empty_slice();
+      return NULL;
   }
-  return grpc_empty_slice();
+  return NULL;
 }
 
-grpc_mdelem grpc_compression_encoding_mdelem(
+grpc_mdelem *grpc_compression_encoding_mdelem(
     grpc_compression_algorithm algorithm) {
   switch (algorithm) {
     case GRPC_COMPRESS_NONE:
@@ -116,7 +122,7 @@ grpc_mdelem grpc_compression_encoding_mdelem(
     default:
       break;
   }
-  return GRPC_MDNULL;
+  return NULL;
 }
 
 void grpc_compression_options_init(grpc_compression_options *opts) {
diff --git a/src/core/lib/http/httpcli_security_connector.c b/src/core/lib/http/httpcli_security_connector.c
index f4f6f3c27a..440817c5a6 100644
--- a/src/core/lib/http/httpcli_security_connector.c
+++ b/src/core/lib/http/httpcli_security_connector.c
@@ -156,7 +156,7 @@ static void on_handshake_done(grpc_exec_ctx *exec_ctx, void *arg,
   if (error != GRPC_ERROR_NONE) {
     const char *msg = grpc_error_string(error);
     gpr_log(GPR_ERROR, "Secure transport setup failed: %s", msg);
-
+    grpc_error_free_string(msg);
     c->func(exec_ctx, c->arg, NULL);
   } else {
     grpc_channel_args_destroy(exec_ctx, args->args);
diff --git a/src/core/lib/iomgr/closure.c b/src/core/lib/iomgr/closure.c
index 509c1ff95d..ec197c7d82 100644
--- a/src/core/lib/iomgr/closure.c
+++ b/src/core/lib/iomgr/closure.c
@@ -34,7 +34,6 @@
 #include "src/core/lib/iomgr/closure.h"
 
 #include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
 
 #include "src/core/lib/profiling/timers.h"
 
diff --git a/src/core/lib/iomgr/closure.h b/src/core/lib/iomgr/closure.h
index 2510d50b42..7ffec29ebb 100644
--- a/src/core/lib/iomgr/closure.h
+++ b/src/core/lib/iomgr/closure.h
@@ -66,7 +66,6 @@ typedef struct grpc_closure_scheduler_vtable {
               grpc_error *error);
   void (*sched)(grpc_exec_ctx *exec_ctx, grpc_closure *closure,
                 grpc_error *error);
-  const char *name;
 } grpc_closure_scheduler_vtable;
 
 /** Abstract type that can schedule closures for execution */
diff --git a/src/core/lib/iomgr/combiner.c b/src/core/lib/iomgr/combiner.c
index ba6c7087a9..c26a73b2b7 100644
--- a/src/core/lib/iomgr/combiner.c
+++ b/src/core/lib/iomgr/combiner.c
@@ -86,17 +86,13 @@ static void combiner_finally_exec_covered(grpc_exec_ctx *exec_ctx,
                                           grpc_error *error);
 
 static const grpc_closure_scheduler_vtable scheduler_uncovered = {
-    combiner_exec_uncovered, combiner_exec_uncovered,
-    "combiner:immediately:uncovered"};
+    combiner_exec_uncovered, combiner_exec_uncovered};
 static const grpc_closure_scheduler_vtable scheduler_covered = {
-    combiner_exec_covered, combiner_exec_covered,
-    "combiner:immediately:covered"};
+    combiner_exec_covered, combiner_exec_covered};
 static const grpc_closure_scheduler_vtable finally_scheduler_uncovered = {
-    combiner_finally_exec_uncovered, combiner_finally_exec_uncovered,
-    "combiner:finally:uncovered"};
+    combiner_finally_exec_uncovered, combiner_finally_exec_uncovered};
 static const grpc_closure_scheduler_vtable finally_scheduler_covered = {
-    combiner_finally_exec_covered, combiner_finally_exec_covered,
-    "combiner:finally:covered"};
+    combiner_finally_exec_covered, combiner_finally_exec_covered};
 
 static void offload(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error);
 
diff --git a/src/core/lib/iomgr/error.c b/src/core/lib/iomgr/error.c
index dbe5b139f9..f6bb3a0477 100644
--- a/src/core/lib/iomgr/error.c
+++ b/src/core/lib/iomgr/error.c
@@ -33,10 +33,13 @@
 
 #include "src/core/lib/iomgr/error.h"
 
+#include <inttypes.h>
+#include <stdbool.h>
 #include <string.h>
 
 #include <grpc/status.h>
 #include <grpc/support/alloc.h>
+#include <grpc/support/avl.h>
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/useful.h>
@@ -45,7 +48,6 @@
 #include <grpc/support/log_windows.h>
 #endif
 
-#include "src/core/lib/iomgr/error_internal.h"
 #include "src/core/lib/profiling/timers.h"
 
 static void destroy_integer(void *key) {}
@@ -126,10 +128,6 @@ static const char *error_int_name(grpc_error_ints key) {
 
 static const char *error_str_name(grpc_error_strs key) {
   switch (key) {
-    case GRPC_ERROR_STR_KEY:
-      return "key";
-    case GRPC_ERROR_STR_VALUE:
-      return "value";
     case GRPC_ERROR_STR_DESCRIPTION:
       return "description";
     case GRPC_ERROR_STR_OS_ERROR:
@@ -162,7 +160,16 @@ static const char *error_time_name(grpc_error_times key) {
   GPR_UNREACHABLE_CODE(return "unknown");
 }
 
-bool grpc_error_is_special(grpc_error *err) {
+struct grpc_error {
+  gpr_refcount refs;
+  gpr_avl ints;
+  gpr_avl strs;
+  gpr_avl times;
+  gpr_avl errs;
+  uintptr_t next_err;
+};
+
+static bool is_special(grpc_error *err) {
   return err == GRPC_ERROR_NONE || err == GRPC_ERROR_OOM ||
          err == GRPC_ERROR_CANCELLED;
 }
@@ -170,7 +177,7 @@ bool grpc_error_is_special(grpc_error *err) {
 #ifdef GRPC_ERROR_REFCOUNT_DEBUG
 grpc_error *grpc_error_ref(grpc_error *err, const char *file, int line,
                            const char *func) {
-  if (grpc_error_is_special(err)) return err;
+  if (is_special(err)) return err;
   gpr_log(GPR_DEBUG, "%p: %" PRIdPTR " -> %" PRIdPTR " [%s:%d %s]", err,
           err->refs.count, err->refs.count + 1, file, line, func);
   gpr_ref(&err->refs);
@@ -178,26 +185,25 @@ grpc_error *grpc_error_ref(grpc_error *err, const char *file, int line,
 }
 #else
 grpc_error *grpc_error_ref(grpc_error *err) {
-  if (grpc_error_is_special(err)) return err;
+  if (is_special(err)) return err;
   gpr_ref(&err->refs);
   return err;
 }
 #endif
 
 static void error_destroy(grpc_error *err) {
-  GPR_ASSERT(!grpc_error_is_special(err));
+  GPR_ASSERT(!is_special(err));
   gpr_avl_unref(err->ints);
   gpr_avl_unref(err->strs);
   gpr_avl_unref(err->errs);
   gpr_avl_unref(err->times);
-  gpr_free((void *)gpr_atm_acq_load(&err->error_string));
   gpr_free(err);
 }
 
 #ifdef GRPC_ERROR_REFCOUNT_DEBUG
 void grpc_error_unref(grpc_error *err, const char *file, int line,
                       const char *func) {
-  if (grpc_error_is_special(err)) return;
+  if (is_special(err)) return;
   gpr_log(GPR_DEBUG, "%p: %" PRIdPTR " -> %" PRIdPTR " [%s:%d %s]", err,
           err->refs.count, err->refs.count - 1, file, line, func);
   if (gpr_unref(&err->refs)) {
@@ -206,7 +212,7 @@ void grpc_error_unref(grpc_error *err, const char *file, int line,
 }
 #else
 void grpc_error_unref(grpc_error *err) {
-  if (grpc_error_is_special(err)) return;
+  if (is_special(err)) return;
   if (gpr_unref(&err->refs)) {
     error_destroy(err);
   }
@@ -241,7 +247,6 @@ grpc_error *grpc_error_create(const char *file, int line, const char *desc,
   err->times = gpr_avl_add(gpr_avl_create(&avl_vtable_times),
                            (void *)(uintptr_t)GRPC_ERROR_TIME_CREATED,
                            box_time(gpr_now(GPR_CLOCK_REALTIME)));
-  gpr_atm_no_barrier_store(&err->error_string, 0);
   gpr_ref_init(&err->refs, 1);
   GPR_TIMER_END("grpc_error_create", 0);
   return err;
@@ -250,10 +255,9 @@ grpc_error *grpc_error_create(const char *file, int line, const char *desc,
 static grpc_error *copy_error_and_unref(grpc_error *in) {
   GPR_TIMER_BEGIN("copy_error_and_unref", 0);
   grpc_error *out;
-  if (grpc_error_is_special(in)) {
+  if (is_special(in)) {
     if (in == GRPC_ERROR_NONE)
-      out = grpc_error_set_int(GRPC_ERROR_CREATE("no error"),
-                               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_OK);
+      out = GRPC_ERROR_CREATE("no error");
     else if (in == GRPC_ERROR_OOM)
       out = GRPC_ERROR_CREATE("oom");
     else if (in == GRPC_ERROR_CANCELLED)
@@ -271,7 +275,6 @@ static grpc_error *copy_error_and_unref(grpc_error *in) {
     out->strs = gpr_avl_ref(in->strs);
     out->errs = gpr_avl_ref(in->errs);
     out->times = gpr_avl_ref(in->times);
-    gpr_atm_no_barrier_store(&out->error_string, 0);
     out->next_err = in->next_err;
     gpr_ref_init(&out->refs, 1);
     GRPC_ERROR_UNREF(in);
@@ -289,29 +292,14 @@ grpc_error *grpc_error_set_int(grpc_error *src, grpc_error_ints which,
   return new;
 }
 
-typedef struct {
-  grpc_error *error;
-  grpc_status_code code;
-  const char *msg;
-} special_error_status_map;
-static special_error_status_map error_status_map[] = {
-    {GRPC_ERROR_NONE, GRPC_STATUS_OK, NULL},
-    {GRPC_ERROR_CANCELLED, GRPC_STATUS_CANCELLED, "Cancelled"},
-    {GRPC_ERROR_OOM, GRPC_STATUS_RESOURCE_EXHAUSTED, "Out of memory"},
-};
-
 bool grpc_error_get_int(grpc_error *err, grpc_error_ints which, intptr_t *p) {
   GPR_TIMER_BEGIN("grpc_error_get_int", 0);
   void *pp;
-  if (grpc_error_is_special(err)) {
-    if (which == GRPC_ERROR_INT_GRPC_STATUS) {
-      for (size_t i = 0; i < GPR_ARRAY_SIZE(error_status_map); i++) {
-        if (error_status_map[i].error == err) {
-          if (p != NULL) *p = error_status_map[i].code;
-          GPR_TIMER_END("grpc_error_get_int", 0);
-          return true;
-        }
-      }
+  if (is_special(err)) {
+    if (err == GRPC_ERROR_CANCELLED && which == GRPC_ERROR_INT_GRPC_STATUS) {
+      *p = GRPC_STATUS_CANCELLED;
+      GPR_TIMER_END("grpc_error_get_int", 0);
+      return true;
     }
     GPR_TIMER_END("grpc_error_get_int", 0);
     return false;
@@ -336,17 +324,66 @@ grpc_error *grpc_error_set_str(grpc_error *src, grpc_error_strs which,
 }
 
 const char *grpc_error_get_str(grpc_error *err, grpc_error_strs which) {
-  if (grpc_error_is_special(err)) {
-    if (which == GRPC_ERROR_STR_GRPC_MESSAGE) {
-      for (size_t i = 0; i < GPR_ARRAY_SIZE(error_status_map); i++) {
-        if (error_status_map[i].error == err) {
-          return error_status_map[i].msg;
-        }
-      }
+  if (is_special(err)) return NULL;
+  return gpr_avl_get(err->strs, (void *)(uintptr_t)which);
+}
+
+typedef struct {
+  grpc_error *error;
+  grpc_status_code code;
+  const char *msg;
+} special_error_status_map;
+static special_error_status_map error_status_map[] = {
+    {GRPC_ERROR_NONE, GRPC_STATUS_OK, ""},
+    {GRPC_ERROR_CANCELLED, GRPC_STATUS_CANCELLED, "RPC cancelled"},
+    {GRPC_ERROR_OOM, GRPC_STATUS_RESOURCE_EXHAUSTED, "Out of memory"},
+};
+
+static grpc_error *recursively_find_error_with_status(grpc_error *error,
+                                                      intptr_t *status) {
+  // If the error itself has a status code, return it.
+  if (grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, status)) {
+    return error;
+  }
+  // Otherwise, search through its children.
+  intptr_t key = 0;
+  while (true) {
+    grpc_error *child_error = gpr_avl_get(error->errs, (void *)key++);
+    if (child_error == NULL) break;
+    grpc_error *result =
+        recursively_find_error_with_status(child_error, status);
+    if (result != NULL) return result;
+  }
+  return NULL;
+}
+
+void grpc_error_get_status(grpc_error *error, grpc_status_code *code,
+                           const char **msg) {
+  // Handle special errors via the static map.
+  for (size_t i = 0; i < GPR_ARRAY_SIZE(error_status_map); ++i) {
+    if (error == error_status_map[i].error) {
+      *code = error_status_map[i].code;
+      *msg = error_status_map[i].msg;
+      return;
     }
-    return NULL;
   }
-  return gpr_avl_get(err->strs, (void *)(uintptr_t)which);
+  // Populate code.
+  // Start with the parent error and recurse through the tree of children
+  // until we find the first one that has a status code.
+  intptr_t status = GRPC_STATUS_UNKNOWN;  // Default in case we don't find one.
+  grpc_error *found_error = recursively_find_error_with_status(error, &status);
+  *code = (grpc_status_code)status;
+  // Now populate msg.
+  // If we found an error with a status code above, use that; otherwise,
+  // fall back to using the parent error.
+  if (found_error == NULL) found_error = error;
+  // If the error has a status message, use it.  Otherwise, fall back to
+  // the error description.
+  *msg = grpc_error_get_str(found_error, GRPC_ERROR_STR_GRPC_MESSAGE);
+  if (*msg == NULL) {
+    *msg = grpc_error_get_str(found_error, GRPC_ERROR_STR_DESCRIPTION);
+    if (*msg == NULL) *msg = "uknown error";  // Just in case.
+  }
 }
 
 grpc_error *grpc_error_add_child(grpc_error *src, grpc_error *child) {
@@ -498,6 +535,7 @@ static void add_errs(gpr_avl_node *n, char **s, size_t *sz, size_t *cap,
   *first = false;
   const char *e = grpc_error_string(n->value);
   append_str(e, s, sz, cap);
+  grpc_error_free_string(e);
   add_errs(n->right, s, sz, cap, first);
 }
 
@@ -519,7 +557,7 @@ static int cmp_kvs(const void *a, const void *b) {
   return strcmp(ka->key, kb->key);
 }
 
-static char *finish_kvs(kv_pairs *kvs) {
+static const char *finish_kvs(kv_pairs *kvs) {
   char *s = NULL;
   size_t sz = 0;
   size_t cap = 0;
@@ -540,18 +578,19 @@ static char *finish_kvs(kv_pairs *kvs) {
   return s;
 }
 
+void grpc_error_free_string(const char *str) {
+  if (str == no_error_string) return;
+  if (str == oom_error_string) return;
+  if (str == cancelled_error_string) return;
+  gpr_free((char *)str);
+}
+
 const char *grpc_error_string(grpc_error *err) {
   GPR_TIMER_BEGIN("grpc_error_string", 0);
   if (err == GRPC_ERROR_NONE) return no_error_string;
   if (err == GRPC_ERROR_OOM) return oom_error_string;
   if (err == GRPC_ERROR_CANCELLED) return cancelled_error_string;
 
-  void *p = (void *)gpr_atm_acq_load(&err->error_string);
-  if (p != NULL) {
-    GPR_TIMER_END("grpc_error_string", 0);
-    return p;
-  }
-
   kv_pairs kvs;
   memset(&kvs, 0, sizeof(kvs));
 
@@ -564,13 +603,7 @@ const char *grpc_error_string(grpc_error *err) {
 
   qsort(kvs.kvs, kvs.num_kvs, sizeof(kv_pair), cmp_kvs);
 
-  char *out = finish_kvs(&kvs);
-
-  if (!gpr_atm_rel_cas(&err->error_string, 0, (gpr_atm)out)) {
-    gpr_free(out);
-    out = (char *)gpr_atm_no_barrier_load(&err->error_string);
-  }
-
+  const char *out = finish_kvs(&kvs);
   GPR_TIMER_END("grpc_error_string", 0);
   return out;
 }
@@ -605,6 +638,7 @@ bool grpc_log_if_error(const char *what, grpc_error *error, const char *file,
   if (error == GRPC_ERROR_NONE) return true;
   const char *msg = grpc_error_string(error);
   gpr_log(file, line, GPR_LOG_SEVERITY_ERROR, "%s: %s", what, msg);
+  grpc_error_free_string(msg);
   GRPC_ERROR_UNREF(error);
   return false;
 }
diff --git a/src/core/lib/iomgr/error.h b/src/core/lib/iomgr/error.h
index ffacdac393..f3f3b80a09 100644
--- a/src/core/lib/iomgr/error.h
+++ b/src/core/lib/iomgr/error.h
@@ -124,11 +124,7 @@ typedef enum {
   /// filename that we were trying to read/write when this error occurred
   GRPC_ERROR_STR_FILENAME,
   /// which data was queued for writing when the error occurred
-  GRPC_ERROR_STR_QUEUED_BUFFERS,
-  /// key associated with the error
-  GRPC_ERROR_STR_KEY,
-  /// value associated with the error
-  GRPC_ERROR_STR_VALUE,
+  GRPC_ERROR_STR_QUEUED_BUFFERS
 } grpc_error_strs;
 
 typedef enum {
@@ -145,6 +141,7 @@ typedef enum {
 #define GRPC_ERROR_CANCELLED ((grpc_error *)4)
 
 const char *grpc_error_string(grpc_error *error);
+void grpc_error_free_string(const char *str);
 
 /// Create an error - but use GRPC_ERROR_CREATE instead
 grpc_error *grpc_error_create(const char *file, int line, const char *desc,
@@ -192,6 +189,12 @@ grpc_error *grpc_error_set_str(grpc_error *src, grpc_error_strs which,
 /// Caller does NOT own return value.
 const char *grpc_error_get_str(grpc_error *error, grpc_error_strs which);
 
+/// A utility function to get the status code and message to be returned
+/// to the application.  If not set in the top-level message, looks
+/// through child errors until it finds the first one with these attributes.
+void grpc_error_get_status(grpc_error *error, grpc_status_code *code,
+                           const char **msg);
+
 /// Add a child error: an error that is believed to have contributed to this
 /// error occurring. Allows root causing high level errors from lower level
 /// errors that contributed to them.
diff --git a/src/core/lib/iomgr/error_internal.h b/src/core/lib/iomgr/error_internal.h
deleted file mode 100644
index 1c89ead4ed..0000000000
--- a/src/core/lib/iomgr/error_internal.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- *
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_IOMGR_ERROR_INTERNAL_H
-#define GRPC_CORE_LIB_IOMGR_ERROR_INTERNAL_H
-
-#include <inttypes.h>
-#include <stdbool.h>
-
-#include <grpc/support/avl.h>
-
-struct grpc_error {
-  gpr_refcount refs;
-  gpr_avl ints;
-  gpr_avl strs;
-  gpr_avl times;
-  gpr_avl errs;
-  uintptr_t next_err;
-  gpr_atm error_string;
-};
-
-bool grpc_error_is_special(grpc_error *err);
-
-#endif /* GRPC_CORE_LIB_IOMGR_ERROR_INTERNAL_H */
diff --git a/src/core/lib/iomgr/ev_epoll_linux.c b/src/core/lib/iomgr/ev_epoll_linux.c
index 39b5c0032e..2a6956ae54 100644
--- a/src/core/lib/iomgr/ev_epoll_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_linux.c
@@ -321,7 +321,7 @@ gpr_atm g_epoll_sync;
 #endif /* defined(GRPC_TSAN) */
 
 static const grpc_closure_scheduler_vtable workqueue_scheduler_vtable = {
-    workqueue_enqueue, workqueue_enqueue, "workqueue"};
+    workqueue_enqueue, workqueue_enqueue};
 
 static void pi_add_ref(polling_island *pi);
 static void pi_unref(grpc_exec_ctx *exec_ctx, polling_island *pi);
@@ -796,7 +796,7 @@ static polling_island *polling_island_merge(polling_island *p,
     gpr_atm_rel_store(&p->merged_to, (gpr_atm)q);
     PI_ADD_REF(q, "pi_merge"); /* To account for the new incoming ref from p */
 
-    workqueue_move_items_to_parent(q);
+    workqueue_move_items_to_parent(p);
   }
   /* else if p == q, nothing needs to be done */
 
@@ -1527,7 +1527,8 @@ static void pollset_work_and_unlock(grpc_exec_ctx *exec_ctx,
         append_error(error, grpc_wakeup_fd_consume_wakeup(&global_wakeup_fd),
                      err_desc);
       } else if (data_ptr == &pi->workqueue_wakeup_fd) {
-        append_error(error, grpc_wakeup_fd_consume_wakeup(&global_wakeup_fd),
+        append_error(error,
+                     grpc_wakeup_fd_consume_wakeup(&pi->workqueue_wakeup_fd),
                      err_desc);
         maybe_do_workqueue_work(exec_ctx, pi);
       } else if (data_ptr == &polling_island_wakeup_fd) {
diff --git a/src/core/lib/iomgr/ev_poll_posix.c b/src/core/lib/iomgr/ev_poll_posix.c
index 5bc5621443..9477ac3688 100644
--- a/src/core/lib/iomgr/ev_poll_posix.c
+++ b/src/core/lib/iomgr/ev_poll_posix.c
@@ -413,9 +413,7 @@ static void fd_orphan(grpc_exec_ctx *exec_ctx, grpc_fd *fd,
                       const char *reason) {
   fd->on_done_closure = on_done;
   fd->released = release_fd != NULL;
-  if (!fd->released) {
-    shutdown(fd->fd, SHUT_RDWR);
-  } else {
+  if (fd->released) {
     *release_fd = fd->fd;
   }
   gpr_mu_lock(&fd->mu);
diff --git a/src/core/lib/iomgr/ev_posix.c b/src/core/lib/iomgr/ev_posix.c
index c106ba5400..2975d619e1 100644
--- a/src/core/lib/iomgr/ev_posix.c
+++ b/src/core/lib/iomgr/ev_posix.c
@@ -52,8 +52,6 @@
  *  tests */
 grpc_poll_function_type grpc_poll_function = poll;
 
-grpc_wakeup_fd grpc_global_wakeup_fd;
-
 static const grpc_event_engine_vtable *g_event_engine;
 static const char *g_poll_strategy_name = NULL;
 
diff --git a/src/core/lib/iomgr/exec_ctx.c b/src/core/lib/iomgr/exec_ctx.c
index 83bb436bd0..6aa788f8e5 100644
--- a/src/core/lib/iomgr/exec_ctx.c
+++ b/src/core/lib/iomgr/exec_ctx.c
@@ -42,16 +42,11 @@
 #include "src/core/lib/profiling/timers.h"
 
 bool grpc_exec_ctx_ready_to_finish(grpc_exec_ctx *exec_ctx) {
-  if ((exec_ctx->flags & GRPC_EXEC_CTX_FLAG_IS_FINISHED) == 0) {
-    if (exec_ctx->check_ready_to_finish(exec_ctx,
-                                        exec_ctx->check_ready_to_finish_arg)) {
-      exec_ctx->flags |= GRPC_EXEC_CTX_FLAG_IS_FINISHED;
-      return true;
-    }
-    return false;
-  } else {
-    return true;
+  if (!exec_ctx->cached_ready_to_finish) {
+    exec_ctx->cached_ready_to_finish = exec_ctx->check_ready_to_finish(
+        exec_ctx, exec_ctx->check_ready_to_finish_arg);
   }
+  return exec_ctx->cached_ready_to_finish;
 }
 
 bool grpc_never_ready_to_finish(grpc_exec_ctx *exec_ctx, void *arg_ignored) {
@@ -87,7 +82,7 @@ bool grpc_exec_ctx_flush(grpc_exec_ctx *exec_ctx) {
 }
 
 void grpc_exec_ctx_finish(grpc_exec_ctx *exec_ctx) {
-  exec_ctx->flags |= GRPC_EXEC_CTX_FLAG_IS_FINISHED;
+  exec_ctx->cached_ready_to_finish = true;
   grpc_exec_ctx_flush(exec_ctx);
 }
 
@@ -106,6 +101,6 @@ void grpc_exec_ctx_global_init(void) {}
 void grpc_exec_ctx_global_shutdown(void) {}
 
 static const grpc_closure_scheduler_vtable exec_ctx_scheduler_vtable = {
-    exec_ctx_run, exec_ctx_sched, "exec_ctx"};
+    exec_ctx_run, exec_ctx_sched};
 static grpc_closure_scheduler exec_ctx_scheduler = {&exec_ctx_scheduler_vtable};
 grpc_closure_scheduler *grpc_schedule_on_exec_ctx = &exec_ctx_scheduler;
diff --git a/src/core/lib/iomgr/exec_ctx.h b/src/core/lib/iomgr/exec_ctx.h
index f99a0fee5f..e566f1b3e8 100644
--- a/src/core/lib/iomgr/exec_ctx.h
+++ b/src/core/lib/iomgr/exec_ctx.h
@@ -43,13 +43,6 @@
 typedef struct grpc_workqueue grpc_workqueue;
 typedef struct grpc_combiner grpc_combiner;
 
-/* This exec_ctx is ready to return: either pre-populated, or cached as soon as
-   the finish_check returns true */
-#define GRPC_EXEC_CTX_FLAG_IS_FINISHED 1
-/* The exec_ctx's thread is (potentially) owned by a call or channel: care
-   should be given to not delete said call/channel from this exec_ctx */
-#define GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP 2
-
 /** Execution context.
  *  A bag of data that collects information along a callstack.
  *  Generally created at public API entry points, and passed down as
@@ -70,26 +63,36 @@ typedef struct grpc_combiner grpc_combiner;
  *  - Instances are always passed as the first argument to a function that
  *    takes it, and always as a pointer (grpc_exec_ctx is never copied).
  */
+#ifndef GRPC_EXECUTION_CONTEXT_SANITIZER
 struct grpc_exec_ctx {
   grpc_closure_list closure_list;
   /** currently active combiner: updated only via combiner.c */
   grpc_combiner *active_combiner;
   /** last active combiner in the active combiner list */
   grpc_combiner *last_combiner;
-  uintptr_t flags;
+  bool cached_ready_to_finish;
   void *check_ready_to_finish_arg;
   bool (*check_ready_to_finish)(grpc_exec_ctx *exec_ctx, void *arg);
 };
 
 /* initializer for grpc_exec_ctx:
    prefer to use GRPC_EXEC_CTX_INIT whenever possible */
-#define GRPC_EXEC_CTX_INITIALIZER(flags, finish_check, finish_check_arg) \
-  { GRPC_CLOSURE_LIST_INIT, NULL, NULL, flags, finish_check_arg, finish_check }
+#define GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(finish_check, finish_check_arg) \
+  { GRPC_CLOSURE_LIST_INIT, NULL, NULL, false, finish_check_arg, finish_check }
+#else
+struct grpc_exec_ctx {
+  bool cached_ready_to_finish;
+  void *check_ready_to_finish_arg;
+  bool (*check_ready_to_finish)(grpc_exec_ctx *exec_ctx, void *arg);
+};
+#define GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(finish_check, finish_check_arg) \
+  { false, finish_check_arg, finish_check }
+#endif
 
 /* initialize an execution context at the top level of an API call into grpc
    (this is safe to use elsewhere, though possibly not as efficient) */
 #define GRPC_EXEC_CTX_INIT \
-  GRPC_EXEC_CTX_INITIALIZER(GRPC_EXEC_CTX_FLAG_IS_FINISHED, NULL, NULL)
+  GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(grpc_always_ready_to_finish, NULL)
 
 extern grpc_closure_scheduler *grpc_schedule_on_exec_ctx;
 
diff --git a/src/core/lib/iomgr/executor.c b/src/core/lib/iomgr/executor.c
index a5b62aa888..852775564f 100644
--- a/src/core/lib/iomgr/executor.c
+++ b/src/core/lib/iomgr/executor.c
@@ -158,7 +158,7 @@ void grpc_executor_shutdown(grpc_exec_ctx *exec_ctx) {
   gpr_mu_destroy(&g_executor.mu);
 }
 
-static const grpc_closure_scheduler_vtable executor_vtable = {
-    executor_push, executor_push, "executor"};
+static const grpc_closure_scheduler_vtable executor_vtable = {executor_push,
+                                                              executor_push};
 static grpc_closure_scheduler executor_scheduler = {&executor_vtable};
 grpc_closure_scheduler *grpc_executor_scheduler = &executor_scheduler;
diff --git a/src/core/lib/iomgr/load_file.c b/src/core/lib/iomgr/load_file.c
index f40c8b28cc..217bc5da59 100644
--- a/src/core/lib/iomgr/load_file.c
+++ b/src/core/lib/iomgr/load_file.c
@@ -47,7 +47,7 @@ grpc_error *grpc_load_file(const char *filename, int add_null_terminator,
                            grpc_slice *output) {
   unsigned char *contents = NULL;
   size_t contents_size = 0;
-  grpc_slice result = grpc_empty_slice();
+  grpc_slice result = gpr_empty_slice();
   FILE *file;
   size_t bytes_read = 0;
   grpc_error *error = GRPC_ERROR_NONE;
diff --git a/src/core/lib/iomgr/resource_quota.c b/src/core/lib/iomgr/resource_quota.c
index 8a7d6cc79e..7639e48632 100644
--- a/src/core/lib/iomgr/resource_quota.c
+++ b/src/core/lib/iomgr/resource_quota.c
@@ -397,15 +397,11 @@ static void ru_slice_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
-static const grpc_slice_refcount_vtable ru_slice_vtable = {
-    ru_slice_ref, ru_slice_unref, grpc_slice_default_eq_impl,
-    grpc_slice_default_hash_impl};
-
 static grpc_slice ru_slice_create(grpc_resource_user *resource_user,
                                   size_t size) {
   ru_slice_refcount *rc = gpr_malloc(sizeof(ru_slice_refcount) + size);
-  rc->base.vtable = &ru_slice_vtable;
-  rc->base.sub_refcount = &rc->base;
+  rc->base.ref = ru_slice_ref;
+  rc->base.unref = ru_slice_unref;
   gpr_ref_init(&rc->refs, 1);
   rc->resource_user = resource_user;
   rc->size = size;
diff --git a/src/core/lib/iomgr/tcp_client_posix.c b/src/core/lib/iomgr/tcp_client_posix.c
index 16b0f4e73c..9a77c92016 100644
--- a/src/core/lib/iomgr/tcp_client_posix.c
+++ b/src/core/lib/iomgr/tcp_client_posix.c
@@ -118,6 +118,7 @@ static void tc_on_alarm(grpc_exec_ctx *exec_ctx, void *acp, grpc_error *error) {
     const char *str = grpc_error_string(error);
     gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: on_alarm: error=%s", ac->addr_str,
             str);
+    grpc_error_free_string(str);
   }
   gpr_mu_lock(&ac->mu);
   if (ac->fd != NULL) {
@@ -177,6 +178,7 @@ static void on_writable(grpc_exec_ctx *exec_ctx, void *acp, grpc_error *error) {
     const char *str = grpc_error_string(error);
     gpr_log(GPR_DEBUG, "CLIENT_CONNECT: %s: on_writable: error=%s",
             ac->addr_str, str);
+    grpc_error_free_string(str);
   }
 
   gpr_mu_lock(&ac->mu);
diff --git a/src/core/lib/iomgr/tcp_posix.c b/src/core/lib/iomgr/tcp_posix.c
index a33e63e845..ece44978b0 100644
--- a/src/core/lib/iomgr/tcp_posix.c
+++ b/src/core/lib/iomgr/tcp_posix.c
@@ -181,7 +181,7 @@ static void call_read_cb(grpc_exec_ctx *exec_ctx, grpc_tcp *tcp,
     size_t i;
     const char *str = grpc_error_string(error);
     gpr_log(GPR_DEBUG, "read: error=%s", str);
-
+    grpc_error_free_string(str);
     for (i = 0; i < tcp->incoming_buffer->count; i++) {
       char *dump = grpc_dump_slice(tcp->incoming_buffer->slices[i],
                                    GPR_DUMP_HEX | GPR_DUMP_ASCII);
@@ -435,6 +435,7 @@ static void tcp_handle_write(grpc_exec_ctx *exec_ctx, void *arg /* grpc_tcp */,
     if (grpc_tcp_trace) {
       const char *str = grpc_error_string(error);
       gpr_log(GPR_DEBUG, "write: %s", str);
+      grpc_error_free_string(str);
     }
 
     grpc_closure_run(exec_ctx, cb, error);
@@ -484,6 +485,7 @@ static void tcp_write(grpc_exec_ctx *exec_ctx, grpc_endpoint *ep,
     if (grpc_tcp_trace) {
       const char *str = grpc_error_string(error);
       gpr_log(GPR_DEBUG, "write: %s", str);
+      grpc_error_free_string(str);
     }
     grpc_closure_sched(exec_ctx, cb, error);
   }
diff --git a/src/core/lib/iomgr/tcp_server_windows.c b/src/core/lib/iomgr/tcp_server_windows.c
index bd4b9b2df1..dafe851ce8 100644
--- a/src/core/lib/iomgr/tcp_server_windows.c
+++ b/src/core/lib/iomgr/tcp_server_windows.c
@@ -343,7 +343,7 @@ static void on_accept(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
   if (error != GRPC_ERROR_NONE) {
     const char *msg = grpc_error_string(error);
     gpr_log(GPR_INFO, "Skipping on_accept due to error: %s", msg);
-
+    grpc_error_free_string(msg);
     gpr_mu_unlock(&sp->server->mu);
     return;
   }
diff --git a/src/core/lib/iomgr/tcp_uv.c b/src/core/lib/iomgr/tcp_uv.c
index 7f4ea49a1c..3ddc79706b 100644
--- a/src/core/lib/iomgr/tcp_uv.c
+++ b/src/core/lib/iomgr/tcp_uv.c
@@ -48,7 +48,6 @@
 #include "src/core/lib/iomgr/network_status_tracker.h"
 #include "src/core/lib/iomgr/resource_quota.h"
 #include "src/core/lib/iomgr/tcp_uv.h"
-#include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 
@@ -157,7 +156,7 @@ static void read_callback(uv_stream_t *stream, ssize_t nread,
       size_t i;
       const char *str = grpc_error_string(error);
       gpr_log(GPR_DEBUG, "read: error=%s", str);
-
+      grpc_error_free_string(str);
       for (i = 0; i < tcp->read_slices->count; i++) {
         char *dump = grpc_dump_slice(tcp->read_slices->slices[i],
                                      GPR_DUMP_HEX | GPR_DUMP_ASCII);
diff --git a/src/core/lib/security/credentials/google_default/google_default_credentials.c b/src/core/lib/security/credentials/google_default/google_default_credentials.c
index a098741b70..d6e1fe3dcf 100644
--- a/src/core/lib/security/credentials/google_default/google_default_credentials.c
+++ b/src/core/lib/security/credentials/google_default/google_default_credentials.c
@@ -177,7 +177,7 @@ static grpc_error *create_default_creds_from_path(
   grpc_auth_json_key key;
   grpc_auth_refresh_token token;
   grpc_call_credentials *result = NULL;
-  grpc_slice creds_data = grpc_empty_slice();
+  grpc_slice creds_data = gpr_empty_slice();
   grpc_error *error = GRPC_ERROR_NONE;
   if (creds_path == NULL) {
     error = GRPC_ERROR_CREATE("creds_path unset");
diff --git a/src/core/lib/security/credentials/plugin/plugin_credentials.c b/src/core/lib/security/credentials/plugin/plugin_credentials.c
index 7bc5dfb403..f90d7dce83 100644
--- a/src/core/lib/security/credentials/plugin/plugin_credentials.c
+++ b/src/core/lib/security/credentials/plugin/plugin_credentials.c
@@ -42,9 +42,7 @@
 #include <grpc/support/sync.h>
 
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/surface/api_trace.h"
-#include "src/core/lib/surface/validate_metadata.h"
 
 typedef struct {
   void *user_data;
@@ -65,9 +63,7 @@ static void plugin_md_request_metadata_ready(void *request,
                                              grpc_status_code status,
                                              const char *error_details) {
   /* called from application code */
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INITIALIZER(
-      GRPC_EXEC_CTX_FLAG_IS_FINISHED | GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP,
-      NULL, NULL);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_metadata_plugin_request *r = (grpc_metadata_plugin_request *)request;
   if (status != GRPC_STATUS_OK) {
     if (error_details != NULL) {
@@ -81,14 +77,13 @@ static void plugin_md_request_metadata_ready(void *request,
     bool seen_illegal_header = false;
     grpc_credentials_md *md_array = NULL;
     for (i = 0; i < num_md; i++) {
-      if (!GRPC_LOG_IF_ERROR("validate_metadata_from_plugin",
-                             grpc_validate_header_key_is_legal(md[i].key))) {
+      if (!grpc_header_key_is_legal(md[i].key, strlen(md[i].key))) {
+        gpr_log(GPR_ERROR, "Plugin added invalid metadata key: %s", md[i].key);
         seen_illegal_header = true;
         break;
-      } else if (!grpc_is_binary_header(md[i].key) &&
-                 !GRPC_LOG_IF_ERROR(
-                     "validate_metadata_from_plugin",
-                     grpc_validate_header_nonbin_value_is_legal(md[i].value))) {
+      } else if (!grpc_is_binary_header(md[i].key, strlen(md[i].key)) &&
+                 !grpc_header_nonbin_value_is_legal(md[i].value,
+                                                    md[i].value_length)) {
         gpr_log(GPR_ERROR, "Plugin added invalid metadata value.");
         seen_illegal_header = true;
         break;
@@ -100,8 +95,9 @@ static void plugin_md_request_metadata_ready(void *request,
     } else if (num_md > 0) {
       md_array = gpr_malloc(num_md * sizeof(grpc_credentials_md));
       for (i = 0; i < num_md; i++) {
-        md_array[i].key = grpc_slice_ref_internal(md[i].key);
-        md_array[i].value = grpc_slice_ref_internal(md[i].value);
+        md_array[i].key = grpc_slice_from_copied_string(md[i].key);
+        md_array[i].value =
+            grpc_slice_from_copied_buffer(md[i].value, md[i].value_length);
       }
       r->cb(&exec_ctx, r->user_data, md_array, num_md, GRPC_CREDENTIALS_OK,
             NULL);
diff --git a/src/core/lib/security/transport/client_auth_filter.c b/src/core/lib/security/transport/client_auth_filter.c
index cf056e8008..b7f6fd23e3 100644
--- a/src/core/lib/security/transport/client_auth_filter.c
+++ b/src/core/lib/security/transport/client_auth_filter.c
@@ -45,7 +45,6 @@
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/core/lib/security/transport/security_connector.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/transport/static_metadata.h"
@@ -55,10 +54,8 @@
 /* We can have a per-call credentials. */
 typedef struct {
   grpc_call_credentials *creds;
-  bool have_host;
-  bool have_method;
-  grpc_slice host;
-  grpc_slice method;
+  grpc_mdstr *host;
+  grpc_mdstr *method;
   /* pollset{_set} bound to this call; if we need to make external
      network requests, they should be done under a pollset added to this
      pollset_set so that work can progress when this call wants work to progress
@@ -92,12 +89,14 @@ static void reset_auth_metadata_context(
   auth_md_context->channel_auth_context = NULL;
 }
 
-static void add_error(grpc_error **combined, grpc_error *error) {
-  if (error == GRPC_ERROR_NONE) return;
-  if (*combined == GRPC_ERROR_NONE) {
-    *combined = GRPC_ERROR_CREATE("Client auth metadata plugin error");
-  }
-  *combined = grpc_error_add_child(*combined, error);
+static void bubble_up_error(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
+                            grpc_status_code status, const char *error_msg) {
+  call_data *calld = elem->call_data;
+  gpr_log(GPR_ERROR, "Client side authentication failure: %s", error_msg);
+  grpc_slice error_slice = grpc_slice_from_copied_string(error_msg);
+  grpc_transport_stream_op_add_close(exec_ctx, &calld->op, status,
+                                     &error_slice);
+  grpc_call_next_op(exec_ctx, elem, &calld->op);
 }
 
 static void on_credentials_metadata(grpc_exec_ctx *exec_ctx, void *user_data,
@@ -111,37 +110,30 @@ static void on_credentials_metadata(grpc_exec_ctx *exec_ctx, void *user_data,
   grpc_metadata_batch *mdb;
   size_t i;
   reset_auth_metadata_context(&calld->auth_md_context);
-  grpc_error *error = GRPC_ERROR_NONE;
   if (status != GRPC_CREDENTIALS_OK) {
-    error = grpc_error_set_int(
-        GRPC_ERROR_CREATE(error_details != NULL && strlen(error_details) > 0
-                              ? error_details
-                              : "Credentials failed to get metadata."),
-        GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAUTHENTICATED);
-  } else {
-    GPR_ASSERT(num_md <= MAX_CREDENTIALS_METADATA_COUNT);
-    GPR_ASSERT(op->send_initial_metadata != NULL);
-    mdb = op->send_initial_metadata;
-    for (i = 0; i < num_md; i++) {
-      add_error(&error,
-                grpc_metadata_batch_add_tail(
-                    exec_ctx, mdb, &calld->md_links[i],
-                    grpc_mdelem_from_slices(
-                        exec_ctx, grpc_slice_ref_internal(md_elems[i].key),
-                        grpc_slice_ref_internal(md_elems[i].value))));
-    }
+    bubble_up_error(exec_ctx, elem, GRPC_STATUS_UNAUTHENTICATED,
+                    (error_details != NULL && strlen(error_details) > 0)
+                        ? error_details
+                        : "Credentials failed to get metadata.");
+    return;
   }
-  if (error == GRPC_ERROR_NONE) {
-    grpc_call_next_op(exec_ctx, elem, op);
-  } else {
-    grpc_transport_stream_op_finish_with_failure(exec_ctx, op, error);
+  GPR_ASSERT(num_md <= MAX_CREDENTIALS_METADATA_COUNT);
+  GPR_ASSERT(op->send_initial_metadata != NULL);
+  mdb = op->send_initial_metadata;
+  for (i = 0; i < num_md; i++) {
+    grpc_metadata_batch_add_tail(
+        mdb, &calld->md_links[i],
+        grpc_mdelem_from_slices(exec_ctx,
+                                grpc_slice_ref_internal(md_elems[i].key),
+                                grpc_slice_ref_internal(md_elems[i].value)));
   }
+  grpc_call_next_op(exec_ctx, elem, op);
 }
 
 void build_auth_metadata_context(grpc_security_connector *sc,
                                  grpc_auth_context *auth_context,
                                  call_data *calld) {
-  char *service = grpc_slice_to_c_string(calld->method);
+  char *service = gpr_strdup(grpc_mdstr_as_c_string(calld->method));
   char *last_slash = strrchr(service, '/');
   char *method_name = NULL;
   char *service_url = NULL;
@@ -157,15 +149,14 @@ void build_auth_metadata_context(grpc_security_connector *sc,
     method_name = gpr_strdup(last_slash + 1);
   }
   if (method_name == NULL) method_name = gpr_strdup("");
-  char *host = grpc_slice_to_c_string(calld->host);
   gpr_asprintf(&service_url, "%s://%s%s",
-               sc->url_scheme == NULL ? "" : sc->url_scheme, host, service);
+               sc->url_scheme == NULL ? "" : sc->url_scheme,
+               grpc_mdstr_as_c_string(calld->host), service);
   calld->auth_md_context.service_url = service_url;
   calld->auth_md_context.method_name = method_name;
   calld->auth_md_context.channel_auth_context =
       GRPC_AUTH_CONTEXT_REF(auth_context, "grpc_auth_metadata_context");
   gpr_free(service);
-  gpr_free(host);
 }
 
 static void send_security_metadata(grpc_exec_ctx *exec_ctx,
@@ -189,12 +180,8 @@ static void send_security_metadata(grpc_exec_ctx *exec_ctx,
     calld->creds = grpc_composite_call_credentials_create(channel_call_creds,
                                                           ctx->creds, NULL);
     if (calld->creds == NULL) {
-      grpc_transport_stream_op_finish_with_failure(
-          exec_ctx, op,
-          grpc_error_set_int(
-              GRPC_ERROR_CREATE(
-                  "Incompatible credentials set on channel and call."),
-              GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_UNAUTHENTICATED));
+      bubble_up_error(exec_ctx, elem, GRPC_STATUS_UNAUTHENTICATED,
+                      "Incompatible credentials set on channel and call.");
       return;
     }
   } else {
@@ -220,14 +207,9 @@ static void on_host_checked(grpc_exec_ctx *exec_ctx, void *user_data,
     send_security_metadata(exec_ctx, elem, &calld->op);
   } else {
     char *error_msg;
-    char *host = grpc_slice_to_c_string(calld->host);
     gpr_asprintf(&error_msg, "Invalid host %s set in :authority metadata.",
-                 host);
-    gpr_free(host);
-    grpc_call_element_signal_error(
-        exec_ctx, elem, grpc_error_set_int(GRPC_ERROR_CREATE(error_msg),
-                                           GRPC_ERROR_INT_GRPC_STATUS,
-                                           GRPC_STATUS_UNAUTHENTICATED));
+                 grpc_mdstr_as_c_string(calld->host));
+    bubble_up_error(exec_ctx, elem, GRPC_STATUS_UNAUTHENTICATED, error_msg);
     gpr_free(error_msg);
   }
 }
@@ -265,30 +247,23 @@ static void auth_start_transport_op(grpc_exec_ctx *exec_ctx,
 
   if (op->send_initial_metadata != NULL) {
     for (l = op->send_initial_metadata->list.head; l != NULL; l = l->next) {
-      grpc_mdelem md = l->md;
+      grpc_mdelem *md = l->md;
       /* Pointer comparison is OK for md_elems created from the same context.
        */
-      if (grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDSTR_AUTHORITY)) {
-        if (calld->have_host) {
-          grpc_slice_unref_internal(exec_ctx, calld->host);
-        }
-        calld->host = grpc_slice_ref_internal(GRPC_MDVALUE(md));
-        calld->have_host = true;
-      } else if (grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDSTR_PATH)) {
-        if (calld->have_method) {
-          grpc_slice_unref_internal(exec_ctx, calld->method);
-        }
-        calld->method = grpc_slice_ref_internal(GRPC_MDVALUE(md));
-        calld->have_method = true;
+      if (md->key == GRPC_MDSTR_AUTHORITY) {
+        if (calld->host != NULL) GRPC_MDSTR_UNREF(exec_ctx, calld->host);
+        calld->host = GRPC_MDSTR_REF(md->value);
+      } else if (md->key == GRPC_MDSTR_PATH) {
+        if (calld->method != NULL) GRPC_MDSTR_UNREF(exec_ctx, calld->method);
+        calld->method = GRPC_MDSTR_REF(md->value);
       }
     }
-    if (calld->have_host) {
-      char *call_host = grpc_slice_to_c_string(calld->host);
+    if (calld->host != NULL) {
+      const char *call_host = grpc_mdstr_as_c_string(calld->host);
       calld->op = *op; /* Copy op (originates from the caller's stack). */
       grpc_channel_security_connector_check_call_host(
           exec_ctx, chand->security_connector, call_host, chand->auth_context,
           on_host_checked, elem);
-      gpr_free(call_host);
       GPR_TIMER_END("auth_start_transport_op", 0);
       return; /* early exit */
     }
@@ -321,11 +296,11 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                               void *ignored) {
   call_data *calld = elem->call_data;
   grpc_call_credentials_unref(exec_ctx, calld->creds);
-  if (calld->have_host) {
-    grpc_slice_unref_internal(exec_ctx, calld->host);
+  if (calld->host != NULL) {
+    GRPC_MDSTR_UNREF(exec_ctx, calld->host);
   }
-  if (calld->have_method) {
-    grpc_slice_unref_internal(exec_ctx, calld->method);
+  if (calld->method != NULL) {
+    GRPC_MDSTR_UNREF(exec_ctx, calld->method);
   }
   reset_auth_metadata_context(&calld->auth_md_context);
 }
diff --git a/src/core/lib/security/transport/security_connector.c b/src/core/lib/security/transport/security_connector.c
index b09127811b..5aa26e0577 100644
--- a/src/core/lib/security/transport/security_connector.c
+++ b/src/core/lib/security/transport/security_connector.c
@@ -601,7 +601,7 @@ static grpc_security_connector_vtable ssl_server_vtable = {
     ssl_server_destroy, ssl_server_check_peer};
 
 static grpc_slice compute_default_pem_root_certs_once(void) {
-  grpc_slice result = grpc_empty_slice();
+  grpc_slice result = gpr_empty_slice();
 
   /* First try to load the roots from the environment. */
   char *default_root_certs_path =
diff --git a/src/core/lib/security/transport/security_handshaker.c b/src/core/lib/security/transport/security_handshaker.c
index 37d57d759b..5e75856c7a 100644
--- a/src/core/lib/security/transport/security_handshaker.c
+++ b/src/core/lib/security/transport/security_handshaker.c
@@ -124,7 +124,7 @@ static void security_handshake_failed_locked(grpc_exec_ctx *exec_ctx,
   }
   const char *msg = grpc_error_string(error);
   gpr_log(GPR_DEBUG, "Security handshake failed: %s", msg);
-
+  grpc_error_free_string(msg);
   if (!h->shutdown) {
     // TODO(ctiller): It is currently necessary to shutdown endpoints
     // before destroying them, even if we know that there are no
diff --git a/src/core/lib/security/transport/server_auth_filter.c b/src/core/lib/security/transport/server_auth_filter.c
index 36e81d6501..5e98ba895d 100644
--- a/src/core/lib/security/transport/server_auth_filter.c
+++ b/src/core/lib/security/transport/server_auth_filter.c
@@ -33,13 +33,12 @@
 
 #include <string.h>
 
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-
 #include "src/core/lib/security/context/security_context.h"
 #include "src/core/lib/security/credentials/credentials.h"
 #include "src/core/lib/security/transport/auth_filters.h"
-#include "src/core/lib/slice/slice_internal.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
 
 typedef struct call_data {
   grpc_metadata_batch *recv_initial_metadata;
@@ -68,34 +67,48 @@ static grpc_metadata_array metadata_batch_to_md_array(
   grpc_metadata_array_init(&result);
   for (l = batch->list.head; l != NULL; l = l->next) {
     grpc_metadata *usr_md = NULL;
-    grpc_mdelem md = l->md;
-    grpc_slice key = GRPC_MDKEY(md);
-    grpc_slice value = GRPC_MDVALUE(md);
+    grpc_mdelem *md = l->md;
+    grpc_mdstr *key = md->key;
+    grpc_mdstr *value = md->value;
     if (result.count == result.capacity) {
       result.capacity = GPR_MAX(result.capacity + 8, result.capacity * 2);
       result.metadata =
           gpr_realloc(result.metadata, result.capacity * sizeof(grpc_metadata));
     }
     usr_md = &result.metadata[result.count++];
-    usr_md->key = grpc_slice_ref_internal(key);
-    usr_md->value = grpc_slice_ref_internal(value);
+    usr_md->key = grpc_mdstr_as_c_string(key);
+    usr_md->value = grpc_mdstr_as_c_string(value);
+    usr_md->value_length = GRPC_SLICE_LENGTH(value->slice);
   }
   return result;
 }
 
-static grpc_filtered_mdelem remove_consumed_md(grpc_exec_ctx *exec_ctx,
-                                               void *user_data,
-                                               grpc_mdelem md) {
+static grpc_mdelem *remove_consumed_md(grpc_exec_ctx *exec_ctx, void *user_data,
+                                       grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
   call_data *calld = elem->call_data;
   size_t i;
   for (i = 0; i < calld->num_consumed_md; i++) {
     const grpc_metadata *consumed_md = &calld->consumed_md[i];
-    if (grpc_slice_eq(GRPC_MDKEY(md), consumed_md->key) &&
-        grpc_slice_eq(GRPC_MDVALUE(md), consumed_md->value))
-      return GRPC_FILTERED_REMOVE();
+    /* Maybe we could do a pointer comparison but we do not have any guarantee
+       that the metadata processor used the same pointers for consumed_md in the
+       callback. */
+    if (GRPC_SLICE_LENGTH(md->key->slice) != strlen(consumed_md->key) ||
+        GRPC_SLICE_LENGTH(md->value->slice) != consumed_md->value_length) {
+      continue;
+    }
+    if (memcmp(GRPC_SLICE_START_PTR(md->key->slice), consumed_md->key,
+               GRPC_SLICE_LENGTH(md->key->slice)) == 0 &&
+        memcmp(GRPC_SLICE_START_PTR(md->value->slice), consumed_md->value,
+               GRPC_SLICE_LENGTH(md->value->slice)) == 0) {
+      return NULL; /* Delete. */
+    }
   }
-  return GRPC_FILTERED_MDELEM(md);
+  return md;
+}
+
+static void destroy_op(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) {
+  gpr_free(arg);
 }
 
 /* called from application code */
@@ -117,33 +130,29 @@ static void on_md_processing_done(
   if (status == GRPC_STATUS_OK) {
     calld->consumed_md = consumed_md;
     calld->num_consumed_md = num_consumed_md;
-    /* TODO(ctiller): propagate error */
-    GRPC_LOG_IF_ERROR(
-        "grpc_metadata_batch_filter",
-        grpc_metadata_batch_filter(&exec_ctx, calld->recv_initial_metadata,
-                                   remove_consumed_md, elem,
-                                   "Response metadata filtering error"));
-    for (size_t i = 0; i < calld->md.count; i++) {
-      grpc_slice_unref_internal(&exec_ctx, calld->md.metadata[i].key);
-      grpc_slice_unref_internal(&exec_ctx, calld->md.metadata[i].value);
-    }
+    grpc_metadata_batch_filter(&exec_ctx, calld->recv_initial_metadata,
+                               remove_consumed_md, elem);
     grpc_metadata_array_destroy(&calld->md);
     grpc_closure_sched(&exec_ctx, calld->on_done_recv, GRPC_ERROR_NONE);
   } else {
-    for (size_t i = 0; i < calld->md.count; i++) {
-      grpc_slice_unref_internal(&exec_ctx, calld->md.metadata[i].key);
-      grpc_slice_unref_internal(&exec_ctx, calld->md.metadata[i].value);
-    }
+    grpc_slice message;
+    grpc_transport_stream_op *close_op = gpr_malloc(sizeof(*close_op));
+    memset(close_op, 0, sizeof(*close_op));
     grpc_metadata_array_destroy(&calld->md);
     error_details = error_details != NULL
                         ? error_details
                         : "Authentication metadata processing failed.";
+    message = grpc_slice_from_copied_string(error_details);
     calld->transport_op->send_initial_metadata = NULL;
     if (calld->transport_op->send_message != NULL) {
       grpc_byte_stream_destroy(&exec_ctx, calld->transport_op->send_message);
       calld->transport_op->send_message = NULL;
     }
     calld->transport_op->send_trailing_metadata = NULL;
+    close_op->on_complete =
+        grpc_closure_create(destroy_op, close_op, grpc_schedule_on_exec_ctx);
+    grpc_transport_stream_op_add_close(&exec_ctx, close_op, status, &message);
+    grpc_call_next_op(&exec_ctx, elem, close_op);
     grpc_closure_sched(&exec_ctx, calld->on_done_recv,
                        grpc_error_set_int(GRPC_ERROR_CREATE(error_details),
                                           GRPC_ERROR_INT_GRPC_STATUS, status));
diff --git a/src/core/lib/security/util/b64.c b/src/core/lib/security/util/b64.c
index 09c8213131..bbd7e335a6 100644
--- a/src/core/lib/security/util/b64.c
+++ b/src/core/lib/security/util/b64.c
@@ -232,5 +232,5 @@ grpc_slice grpc_base64_decode_with_len(grpc_exec_ctx *exec_ctx, const char *b64,
 
 fail:
   grpc_slice_unref_internal(exec_ctx, result);
-  return grpc_empty_slice();
+  return gpr_empty_slice();
 }
diff --git a/src/core/lib/slice/slice.c b/src/core/lib/slice/slice.c
index 1cddf062cd..76118102ec 100644
--- a/src/core/lib/slice/slice.c
+++ b/src/core/lib/slice/slice.c
@@ -41,30 +41,23 @@
 
 #include "src/core/lib/iomgr/exec_ctx.h"
 
-char *grpc_slice_to_c_string(grpc_slice slice) {
-  char *out = gpr_malloc(GRPC_SLICE_LENGTH(slice) + 1);
-  memcpy(out, GRPC_SLICE_START_PTR(slice), GRPC_SLICE_LENGTH(slice));
-  out[GRPC_SLICE_LENGTH(slice)] = 0;
-  return out;
-}
-
-grpc_slice grpc_empty_slice(void) {
+grpc_slice gpr_empty_slice(void) {
   grpc_slice out;
-  out.refcount = NULL;
+  out.refcount = 0;
   out.data.inlined.length = 0;
   return out;
 }
 
 grpc_slice grpc_slice_ref_internal(grpc_slice slice) {
   if (slice.refcount) {
-    slice.refcount->vtable->ref(slice.refcount);
+    slice.refcount->ref(slice.refcount);
   }
   return slice;
 }
 
 void grpc_slice_unref_internal(grpc_exec_ctx *exec_ctx, grpc_slice slice) {
   if (slice.refcount) {
-    slice.refcount->vtable->unref(exec_ctx, slice.refcount);
+    slice.refcount->unref(exec_ctx, slice.refcount);
   }
 }
 
@@ -85,24 +78,16 @@ void grpc_slice_unref(grpc_slice slice) {
 static void noop_ref(void *unused) {}
 static void noop_unref(grpc_exec_ctx *exec_ctx, void *unused) {}
 
-static const grpc_slice_refcount_vtable noop_refcount_vtable = {
-    noop_ref, noop_unref, grpc_slice_default_eq_impl,
-    grpc_slice_default_hash_impl};
-static grpc_slice_refcount noop_refcount = {&noop_refcount_vtable,
-                                            &noop_refcount};
+static grpc_slice_refcount noop_refcount = {noop_ref, noop_unref};
 
-grpc_slice grpc_slice_from_static_buffer(const void *s, size_t len) {
+grpc_slice grpc_slice_from_static_string(const char *s) {
   grpc_slice slice;
   slice.refcount = &noop_refcount;
   slice.data.refcounted.bytes = (uint8_t *)s;
-  slice.data.refcounted.length = len;
+  slice.data.refcounted.length = strlen(s);
   return slice;
 }
 
-grpc_slice grpc_slice_from_static_string(const char *s) {
-  return grpc_slice_from_static_buffer(s, strlen(s));
-}
-
 /* grpc_slice_new support structures - we create a refcount object extended
    with the user provided data pointer & destroy function */
 typedef struct new_slice_refcount {
@@ -125,18 +110,14 @@ static void new_slice_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
-static const grpc_slice_refcount_vtable new_slice_vtable = {
-    new_slice_ref, new_slice_unref, grpc_slice_default_eq_impl,
-    grpc_slice_default_hash_impl};
-
 grpc_slice grpc_slice_new_with_user_data(void *p, size_t len,
                                          void (*destroy)(void *),
                                          void *user_data) {
   grpc_slice slice;
   new_slice_refcount *rc = gpr_malloc(sizeof(new_slice_refcount));
   gpr_ref_init(&rc->refs, 1);
-  rc->rc.vtable = &new_slice_vtable;
-  rc->rc.sub_refcount = &rc->rc;
+  rc->rc.ref = new_slice_ref;
+  rc->rc.unref = new_slice_unref;
   rc->user_destroy = destroy;
   rc->user_data = user_data;
 
@@ -174,18 +155,14 @@ static void new_with_len_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
-static const grpc_slice_refcount_vtable new_with_len_vtable = {
-    new_with_len_ref, new_with_len_unref, grpc_slice_default_eq_impl,
-    grpc_slice_default_hash_impl};
-
 grpc_slice grpc_slice_new_with_len(void *p, size_t len,
                                    void (*destroy)(void *, size_t)) {
   grpc_slice slice;
   new_with_len_slice_refcount *rc =
       gpr_malloc(sizeof(new_with_len_slice_refcount));
   gpr_ref_init(&rc->refs, 1);
-  rc->rc.vtable = &new_with_len_vtable;
-  rc->rc.sub_refcount = &rc->rc;
+  rc->rc.ref = new_with_len_ref;
+  rc->rc.unref = new_with_len_unref;
   rc->user_destroy = destroy;
   rc->user_data = p;
   rc->user_length = len;
@@ -223,10 +200,6 @@ static void malloc_unref(grpc_exec_ctx *exec_ctx, void *p) {
   }
 }
 
-static const grpc_slice_refcount_vtable malloc_vtable = {
-    malloc_ref, malloc_unref, grpc_slice_default_eq_impl,
-    grpc_slice_default_hash_impl};
-
 grpc_slice grpc_slice_malloc(size_t length) {
   grpc_slice slice;
 
@@ -246,8 +219,8 @@ grpc_slice grpc_slice_malloc(size_t length) {
        this reference. */
     gpr_ref_init(&rc->refs, 1);
 
-    rc->base.vtable = &malloc_vtable;
-    rc->base.sub_refcount = &rc->base;
+    rc->base.ref = malloc_ref;
+    rc->base.unref = malloc_unref;
 
     /* Build up the slice to be returned. */
     /* The slices refcount points back to the allocated block. */
@@ -274,7 +247,7 @@ grpc_slice grpc_slice_sub_no_ref(grpc_slice source, size_t begin, size_t end) {
     GPR_ASSERT(source.data.refcounted.length >= end);
 
     /* Build the result */
-    subset.refcount = source.refcount->sub_refcount;
+    subset.refcount = source.refcount;
     /* Point into the source array */
     subset.data.refcounted.bytes = source.data.refcounted.bytes + begin;
     subset.data.refcounted.length = end - begin;
@@ -300,7 +273,7 @@ grpc_slice grpc_slice_sub(grpc_slice source, size_t begin, size_t end) {
   } else {
     subset = grpc_slice_sub_no_ref(source, begin, end);
     /* Bump the refcount */
-    subset.refcount->vtable->ref(subset.refcount);
+    subset.refcount->ref(subset.refcount);
   }
   return subset;
 }
@@ -327,14 +300,13 @@ grpc_slice grpc_slice_split_tail(grpc_slice *source, size_t split) {
              tail_length);
     } else {
       /* Build the result */
-      tail.refcount = source->refcount->sub_refcount;
+      tail.refcount = source->refcount;
       /* Bump the refcount */
-      tail.refcount->vtable->ref(tail.refcount);
+      tail.refcount->ref(tail.refcount);
       /* Point into the source array */
       tail.data.refcounted.bytes = source->data.refcounted.bytes + split;
       tail.data.refcounted.length = tail_length;
     }
-    source->refcount = source->refcount->sub_refcount;
     source->data.refcounted.length = split;
   }
 
@@ -360,20 +332,18 @@ grpc_slice grpc_slice_split_head(grpc_slice *source, size_t split) {
     head.refcount = NULL;
     head.data.inlined.length = (uint8_t)split;
     memcpy(head.data.inlined.bytes, source->data.refcounted.bytes, split);
-    source->refcount = source->refcount->sub_refcount;
     source->data.refcounted.bytes += split;
     source->data.refcounted.length -= split;
   } else {
     GPR_ASSERT(source->data.refcounted.length >= split);
 
     /* Build the result */
-    head.refcount = source->refcount->sub_refcount;
+    head.refcount = source->refcount;
     /* Bump the refcount */
-    head.refcount->vtable->ref(head.refcount);
+    head.refcount->ref(head.refcount);
     /* Point into the source array */
     head.data.refcounted.bytes = source->data.refcounted.bytes;
     head.data.refcounted.length = split;
-    source->refcount = source->refcount->sub_refcount;
     source->data.refcounted.bytes += split;
     source->data.refcounted.length -= split;
   }
@@ -381,19 +351,6 @@ grpc_slice grpc_slice_split_head(grpc_slice *source, size_t split) {
   return head;
 }
 
-int grpc_slice_default_eq_impl(grpc_slice a, grpc_slice b) {
-  return GRPC_SLICE_LENGTH(a) == GRPC_SLICE_LENGTH(b) &&
-         0 == memcmp(GRPC_SLICE_START_PTR(a), GRPC_SLICE_START_PTR(b),
-                     GRPC_SLICE_LENGTH(a));
-}
-
-int grpc_slice_eq(grpc_slice a, grpc_slice b) {
-  if (a.refcount && b.refcount && a.refcount->vtable == b.refcount->vtable) {
-    return a.refcount->vtable->eq(a, b);
-  }
-  return grpc_slice_default_eq_impl(a, b);
-}
-
 int grpc_slice_cmp(grpc_slice a, grpc_slice b) {
   int d = (int)(GRPC_SLICE_LENGTH(a) - GRPC_SLICE_LENGTH(b));
   if (d != 0) return d;
@@ -410,55 +367,8 @@ int grpc_slice_str_cmp(grpc_slice a, const char *b) {
 
 int grpc_slice_is_equivalent(grpc_slice a, grpc_slice b) {
   if (a.refcount == NULL || b.refcount == NULL) {
-    return grpc_slice_eq(a, b);
+    return grpc_slice_cmp(a, b) == 0;
   }
   return a.data.refcounted.length == b.data.refcounted.length &&
          a.data.refcounted.bytes == b.data.refcounted.bytes;
 }
-
-int grpc_slice_buf_start_eq(grpc_slice a, const void *b, size_t len) {
-  if (GRPC_SLICE_LENGTH(a) < len) return 0;
-  return 0 == memcmp(GRPC_SLICE_START_PTR(a), b, len);
-}
-
-int grpc_slice_rchr(grpc_slice s, char c) {
-  const char *b = (const char *)GRPC_SLICE_START_PTR(s);
-  int i;
-  for (i = (int)GRPC_SLICE_LENGTH(s) - 1; i != -1 && b[i] != c; i--)
-    ;
-  return i;
-}
-
-int grpc_slice_chr(grpc_slice s, char c) {
-  const char *b = (const char *)GRPC_SLICE_START_PTR(s);
-  const char *p = memchr(b, c, GRPC_SLICE_LENGTH(s));
-  return p == NULL ? -1 : (int)(p - b);
-}
-
-int grpc_slice_slice(grpc_slice haystack, grpc_slice needle) {
-  size_t haystack_len = GRPC_SLICE_LENGTH(haystack);
-  const uint8_t *haystack_bytes = GRPC_SLICE_START_PTR(haystack);
-  size_t needle_len = GRPC_SLICE_LENGTH(needle);
-  const uint8_t *needle_bytes = GRPC_SLICE_START_PTR(needle);
-
-  if (haystack_len == 0 || needle_len == 0) return -1;
-  if (haystack_len < needle_len) return -1;
-  if (haystack_len == needle_len)
-    return grpc_slice_eq(haystack, needle) ? 0 : -1;
-  if (needle_len == 1) return grpc_slice_chr(haystack, (char)*needle_bytes);
-
-  const uint8_t *last = haystack_bytes + haystack_len - needle_len;
-  for (const uint8_t *cur = haystack_bytes; cur != last; ++cur) {
-    if (0 == memcmp(cur, needle_bytes, needle_len)) {
-      return (int)(cur - haystack_bytes);
-    }
-  }
-  return -1;
-}
-
-grpc_slice grpc_slice_dup(grpc_slice a) {
-  grpc_slice copy = grpc_slice_malloc(GRPC_SLICE_LENGTH(a));
-  memcpy(GRPC_SLICE_START_PTR(copy), GRPC_SLICE_START_PTR(a),
-         GRPC_SLICE_LENGTH(a));
-  return copy;
-}
diff --git a/src/core/lib/slice/slice_buffer.c b/src/core/lib/slice/slice_buffer.c
index 08eaf4963a..9176dc8a42 100644
--- a/src/core/lib/slice/slice_buffer.c
+++ b/src/core/lib/slice/slice_buffer.c
@@ -46,15 +46,27 @@
 #define GROW(x) (3 * (x) / 2)
 
 static void maybe_embiggen(grpc_slice_buffer *sb) {
-  if (sb->count == sb->capacity) {
+  if (sb->base_slices != sb->slices) {
+    memmove(sb->base_slices, sb->slices, sb->count * sizeof(grpc_slice));
+    sb->slices = sb->base_slices;
+  }
+
+  /* How far away from sb->base_slices is sb->slices pointer */
+  size_t slice_offset = (size_t)(sb->slices - sb->base_slices);
+  size_t slice_count = sb->count + slice_offset;
+
+  if (slice_count == sb->capacity) {
     sb->capacity = GROW(sb->capacity);
-    GPR_ASSERT(sb->capacity > sb->count);
-    if (sb->slices == sb->inlined) {
-      sb->slices = gpr_malloc(sb->capacity * sizeof(grpc_slice));
-      memcpy(sb->slices, sb->inlined, sb->count * sizeof(grpc_slice));
+    GPR_ASSERT(sb->capacity > slice_count);
+    if (sb->base_slices == sb->inlined) {
+      sb->base_slices = gpr_malloc(sb->capacity * sizeof(grpc_slice));
+      memcpy(sb->base_slices, sb->inlined, slice_count * sizeof(grpc_slice));
     } else {
-      sb->slices = gpr_realloc(sb->slices, sb->capacity * sizeof(grpc_slice));
+      sb->base_slices =
+          gpr_realloc(sb->base_slices, sb->capacity * sizeof(grpc_slice));
     }
+
+    sb->slices = sb->base_slices + slice_offset;
   }
 }
 
@@ -62,14 +74,14 @@ void grpc_slice_buffer_init(grpc_slice_buffer *sb) {
   sb->count = 0;
   sb->length = 0;
   sb->capacity = GRPC_SLICE_BUFFER_INLINE_ELEMENTS;
-  sb->slices = sb->inlined;
+  sb->base_slices = sb->slices = sb->inlined;
 }
 
 void grpc_slice_buffer_destroy_internal(grpc_exec_ctx *exec_ctx,
                                         grpc_slice_buffer *sb) {
   grpc_slice_buffer_reset_and_unref_internal(exec_ctx, sb);
-  if (sb->slices != sb->inlined) {
-    gpr_free(sb->slices);
+  if (sb->base_slices != sb->inlined) {
+    gpr_free(sb->base_slices);
   }
 }
 
@@ -166,7 +178,6 @@ void grpc_slice_buffer_pop(grpc_slice_buffer *sb) {
 void grpc_slice_buffer_reset_and_unref_internal(grpc_exec_ctx *exec_ctx,
                                                 grpc_slice_buffer *sb) {
   size_t i;
-
   for (i = 0; i < sb->count; i++) {
     grpc_slice_unref_internal(exec_ctx, sb->slices[i]);
   }
@@ -182,32 +193,45 @@ void grpc_slice_buffer_reset_and_unref(grpc_slice_buffer *sb) {
 }
 
 void grpc_slice_buffer_swap(grpc_slice_buffer *a, grpc_slice_buffer *b) {
-  GPR_SWAP(size_t, a->count, b->count);
-  GPR_SWAP(size_t, a->capacity, b->capacity);
-  GPR_SWAP(size_t, a->length, b->length);
+  size_t a_offset = (size_t)(a->slices - a->base_slices);
+  size_t b_offset = (size_t)(b->slices - b->base_slices);
 
-  if (a->slices == a->inlined) {
-    if (b->slices == b->inlined) {
+  size_t a_count = a->count + a_offset;
+  size_t b_count = b->count + b_offset;
+
+  if (a->base_slices == a->inlined) {
+    if (b->base_slices == b->inlined) {
       /* swap contents of inlined buffer */
       grpc_slice temp[GRPC_SLICE_BUFFER_INLINE_ELEMENTS];
-      memcpy(temp, a->slices, b->count * sizeof(grpc_slice));
-      memcpy(a->slices, b->slices, a->count * sizeof(grpc_slice));
-      memcpy(b->slices, temp, b->count * sizeof(grpc_slice));
+      memcpy(temp, a->base_slices, a_count * sizeof(grpc_slice));
+      memcpy(a->base_slices, b->base_slices, b_count * sizeof(grpc_slice));
+      memcpy(b->base_slices, temp, a_count * sizeof(grpc_slice));
     } else {
       /* a is inlined, b is not - copy a inlined into b, fix pointers */
-      a->slices = b->slices;
-      b->slices = b->inlined;
-      memcpy(b->slices, a->inlined, b->count * sizeof(grpc_slice));
+      a->base_slices = b->base_slices;
+      b->base_slices = b->inlined;
+      memcpy(b->base_slices, a->inlined, a_count * sizeof(grpc_slice));
     }
-  } else if (b->slices == b->inlined) {
+  } else if (b->base_slices == b->inlined) {
     /* b is inlined, a is not - copy b inlined int a, fix pointers */
-    b->slices = a->slices;
-    a->slices = a->inlined;
-    memcpy(a->slices, b->inlined, a->count * sizeof(grpc_slice));
+    b->base_slices = a->base_slices;
+    a->base_slices = a->inlined;
+    memcpy(a->base_slices, b->inlined, b_count * sizeof(grpc_slice));
   } else {
     /* no inlining: easy swap */
-    GPR_SWAP(grpc_slice *, a->slices, b->slices);
+    GPR_SWAP(grpc_slice *, a->base_slices, b->base_slices);
   }
+
+  /* Update the slices pointers (cannot do a GPR_SWAP on slices fields here).
+   * Also note that since the base_slices pointers are already swapped we need
+   * use 'b_offset' for 'a->base_slices' and vice versa */
+  a->slices = a->base_slices + b_offset;
+  b->slices = b->base_slices + a_offset;
+
+  /* base_slices and slices fields are correctly set. Swap all other fields */
+  GPR_SWAP(size_t, a->count, b->count);
+  GPR_SWAP(size_t, a->capacity, b->capacity);
+  GPR_SWAP(size_t, a->length, b->length);
 }
 
 void grpc_slice_buffer_move_into(grpc_slice_buffer *src,
@@ -229,7 +253,6 @@ void grpc_slice_buffer_move_into(grpc_slice_buffer *src,
 
 void grpc_slice_buffer_move_first(grpc_slice_buffer *src, size_t n,
                                   grpc_slice_buffer *dst) {
-  size_t src_idx;
   size_t output_len = dst->length + n;
   size_t new_input_len = src->length - n;
   GPR_ASSERT(src->length >= n);
@@ -237,34 +260,55 @@ void grpc_slice_buffer_move_first(grpc_slice_buffer *src, size_t n,
     grpc_slice_buffer_move_into(src, dst);
     return;
   }
-  src_idx = 0;
-  while (src_idx < src->capacity) {
-    grpc_slice slice = src->slices[src_idx];
+
+  while (src->count > 0) {
+    grpc_slice slice = grpc_slice_buffer_take_first(src);
     size_t slice_len = GRPC_SLICE_LENGTH(slice);
     if (n > slice_len) {
       grpc_slice_buffer_add(dst, slice);
       n -= slice_len;
-      src_idx++;
     } else if (n == slice_len) {
       grpc_slice_buffer_add(dst, slice);
-      src_idx++;
       break;
     } else { /* n < slice_len */
-      src->slices[src_idx] = grpc_slice_split_tail(&slice, n);
+      grpc_slice_buffer_undo_take_first(src, grpc_slice_split_tail(&slice, n));
       GPR_ASSERT(GRPC_SLICE_LENGTH(slice) == n);
-      GPR_ASSERT(GRPC_SLICE_LENGTH(src->slices[src_idx]) == slice_len - n);
       grpc_slice_buffer_add(dst, slice);
       break;
     }
   }
   GPR_ASSERT(dst->length == output_len);
-  memmove(src->slices, src->slices + src_idx,
-          sizeof(grpc_slice) * (src->count - src_idx));
-  src->count -= src_idx;
-  src->length = new_input_len;
+  GPR_ASSERT(src->length == new_input_len);
   GPR_ASSERT(src->count > 0);
 }
 
+void grpc_slice_buffer_move_first_into_buffer(grpc_exec_ctx *exec_ctx,
+                                              grpc_slice_buffer *src, size_t n,
+                                              void *dst) {
+  char *dstp = dst;
+  GPR_ASSERT(src->length >= n);
+
+  while (n > 0) {
+    grpc_slice slice = grpc_slice_buffer_take_first(src);
+    size_t slice_len = GRPC_SLICE_LENGTH(slice);
+    if (slice_len > n) {
+      memcpy(dstp, GRPC_SLICE_START_PTR(slice), n);
+      grpc_slice_buffer_undo_take_first(
+          src, grpc_slice_sub_no_ref(slice, n, slice_len));
+      n = 0;
+    } else if (slice_len == n) {
+      memcpy(dstp, GRPC_SLICE_START_PTR(slice), n);
+      grpc_slice_unref_internal(exec_ctx, slice);
+      n = 0;
+    } else {
+      memcpy(dstp, GRPC_SLICE_START_PTR(slice), slice_len);
+      dstp += slice_len;
+      n -= slice_len;
+      grpc_slice_unref_internal(exec_ctx, slice);
+    }
+  }
+}
+
 void grpc_slice_buffer_trim_end(grpc_slice_buffer *sb, size_t n,
                                 grpc_slice_buffer *garbage) {
   GPR_ASSERT(n <= sb->length);
@@ -293,8 +337,17 @@ grpc_slice grpc_slice_buffer_take_first(grpc_slice_buffer *sb) {
   grpc_slice slice;
   GPR_ASSERT(sb->count > 0);
   slice = sb->slices[0];
-  memmove(&sb->slices[0], &sb->slices[1], (sb->count - 1) * sizeof(grpc_slice));
+  sb->slices++;
   sb->count--;
   sb->length -= GRPC_SLICE_LENGTH(slice);
+
   return slice;
 }
+
+void grpc_slice_buffer_undo_take_first(grpc_slice_buffer *sb,
+                                       grpc_slice slice) {
+  sb->slices--;
+  sb->slices[0] = slice;
+  sb->count++;
+  sb->length += GRPC_SLICE_LENGTH(slice);
+}
diff --git a/src/core/lib/slice/slice_intern.c b/src/core/lib/slice/slice_intern.c
deleted file mode 100644
index 7cbd17bffd..0000000000
--- a/src/core/lib/slice/slice_intern.c
+++ /dev/null
@@ -1,344 +0,0 @@
-/*
- *
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include "src/core/lib/slice/slice_internal.h"
-
-#include <string.h>
-
-#include <grpc/support/alloc.h>
-#include <grpc/support/log.h>
-
-#include "src/core/lib/iomgr/iomgr_internal.h" /* for iomgr_abort_on_leaks() */
-#include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
-#include "src/core/lib/support/murmur_hash.h"
-#include "src/core/lib/transport/static_metadata.h"
-
-#define LOG2_SHARD_COUNT 5
-#define SHARD_COUNT (1 << LOG2_SHARD_COUNT)
-#define INITIAL_SHARD_CAPACITY 8
-
-#define TABLE_IDX(hash, capacity) (((hash) >> LOG2_SHARD_COUNT) % (capacity))
-#define SHARD_IDX(hash) ((hash) & ((1 << LOG2_SHARD_COUNT) - 1))
-
-typedef struct interned_slice_refcount {
-  grpc_slice_refcount base;
-  grpc_slice_refcount sub;
-  size_t length;
-  gpr_atm refcnt;
-  uint32_t hash;
-  struct interned_slice_refcount *bucket_next;
-} interned_slice_refcount;
-
-typedef struct slice_shard {
-  gpr_mu mu;
-  interned_slice_refcount **strs;
-  size_t count;
-  size_t capacity;
-} slice_shard;
-
-/* hash seed: decided at initialization time */
-static uint32_t g_hash_seed;
-static int g_forced_hash_seed = 0;
-
-static slice_shard g_shards[SHARD_COUNT];
-
-typedef struct {
-  uint32_t hash;
-  uint32_t idx;
-} static_metadata_hash_ent;
-
-static static_metadata_hash_ent
-    static_metadata_hash[4 * GRPC_STATIC_MDSTR_COUNT];
-static uint32_t max_static_metadata_hash_probe;
-static uint32_t static_metadata_hash_values[GRPC_STATIC_MDSTR_COUNT];
-
-static void interned_slice_ref(void *p) {
-  interned_slice_refcount *s = p;
-  GPR_ASSERT(gpr_atm_no_barrier_fetch_add(&s->refcnt, 1) > 0);
-}
-
-static void interned_slice_destroy(interned_slice_refcount *s) {
-  slice_shard *shard = &g_shards[SHARD_IDX(s->hash)];
-  gpr_mu_lock(&shard->mu);
-  GPR_ASSERT(0 == gpr_atm_no_barrier_load(&s->refcnt));
-  interned_slice_refcount **prev_next;
-  interned_slice_refcount *cur;
-  for (prev_next = &shard->strs[TABLE_IDX(s->hash, shard->capacity)],
-      cur = *prev_next;
-       cur != s; prev_next = &cur->bucket_next, cur = cur->bucket_next)
-    ;
-  *prev_next = cur->bucket_next;
-  shard->count--;
-  gpr_free(s);
-  gpr_mu_unlock(&shard->mu);
-}
-
-static void interned_slice_unref(grpc_exec_ctx *exec_ctx, void *p) {
-  interned_slice_refcount *s = p;
-  if (1 == gpr_atm_full_fetch_add(&s->refcnt, -1)) {
-    interned_slice_destroy(s);
-  }
-}
-
-static void interned_slice_sub_ref(void *p) {
-  interned_slice_ref(((char *)p) - offsetof(interned_slice_refcount, sub));
-}
-
-static void interned_slice_sub_unref(grpc_exec_ctx *exec_ctx, void *p) {
-  interned_slice_unref(exec_ctx,
-                       ((char *)p) - offsetof(interned_slice_refcount, sub));
-}
-
-static uint32_t interned_slice_hash(grpc_slice slice) {
-  interned_slice_refcount *s = (interned_slice_refcount *)slice.refcount;
-  return s->hash;
-}
-
-static int interned_slice_eq(grpc_slice a, grpc_slice b) {
-  return a.refcount == b.refcount;
-}
-
-static const grpc_slice_refcount_vtable interned_slice_vtable = {
-    interned_slice_ref, interned_slice_unref, interned_slice_eq,
-    interned_slice_hash};
-static const grpc_slice_refcount_vtable interned_slice_sub_vtable = {
-    interned_slice_sub_ref, interned_slice_sub_unref,
-    grpc_slice_default_eq_impl, grpc_slice_default_hash_impl};
-
-static void grow_shard(slice_shard *shard) {
-  size_t capacity = shard->capacity * 2;
-  size_t i;
-  interned_slice_refcount **strtab;
-  interned_slice_refcount *s, *next;
-
-  GPR_TIMER_BEGIN("grow_strtab", 0);
-
-  strtab = gpr_malloc(sizeof(interned_slice_refcount *) * capacity);
-  memset(strtab, 0, sizeof(interned_slice_refcount *) * capacity);
-
-  for (i = 0; i < shard->capacity; i++) {
-    for (s = shard->strs[i]; s; s = next) {
-      size_t idx = TABLE_IDX(s->hash, capacity);
-      next = s->bucket_next;
-      s->bucket_next = strtab[idx];
-      strtab[idx] = s;
-    }
-  }
-
-  gpr_free(shard->strs);
-  shard->strs = strtab;
-  shard->capacity = capacity;
-
-  GPR_TIMER_END("grow_strtab", 0);
-}
-
-static grpc_slice materialize(interned_slice_refcount *s) {
-  grpc_slice slice;
-  slice.refcount = &s->base;
-  slice.data.refcounted.bytes = (uint8_t *)(s + 1);
-  slice.data.refcounted.length = s->length;
-  return slice;
-}
-
-uint32_t grpc_slice_default_hash_impl(grpc_slice s) {
-  return gpr_murmur_hash3(GRPC_SLICE_START_PTR(s), GRPC_SLICE_LENGTH(s),
-                          g_hash_seed);
-}
-
-uint32_t grpc_static_slice_hash(grpc_slice s) {
-  return static_metadata_hash_values[GRPC_STATIC_METADATA_INDEX(s)];
-}
-
-int grpc_static_slice_eq(grpc_slice a, grpc_slice b) {
-  return GRPC_STATIC_METADATA_INDEX(a) == GRPC_STATIC_METADATA_INDEX(b);
-}
-
-uint32_t grpc_slice_hash(grpc_slice s) {
-  return s.refcount == NULL ? grpc_slice_default_hash_impl(s)
-                            : s.refcount->vtable->hash(s);
-}
-
-grpc_slice grpc_slice_maybe_static_intern(grpc_slice slice,
-                                          bool *returned_slice_is_different) {
-  if (GRPC_IS_STATIC_METADATA_STRING(slice)) {
-    return slice;
-  }
-
-  uint32_t hash = grpc_slice_hash(slice);
-  for (uint32_t i = 0; i <= max_static_metadata_hash_probe; i++) {
-    static_metadata_hash_ent ent =
-        static_metadata_hash[(hash + i) % GPR_ARRAY_SIZE(static_metadata_hash)];
-    if (ent.hash == hash && ent.idx < GRPC_STATIC_MDSTR_COUNT &&
-        grpc_slice_eq(grpc_static_slice_table[ent.idx], slice)) {
-      *returned_slice_is_different = true;
-      return grpc_static_slice_table[ent.idx];
-    }
-  }
-
-  return slice;
-}
-
-bool grpc_slice_is_interned(grpc_slice slice) {
-  return (slice.refcount && slice.refcount->vtable == &interned_slice_vtable) ||
-         GRPC_IS_STATIC_METADATA_STRING(slice);
-}
-
-grpc_slice grpc_slice_intern(grpc_slice slice) {
-  if (GRPC_IS_STATIC_METADATA_STRING(slice)) {
-    return slice;
-  }
-
-  uint32_t hash = grpc_slice_hash(slice);
-  for (uint32_t i = 0; i <= max_static_metadata_hash_probe; i++) {
-    static_metadata_hash_ent ent =
-        static_metadata_hash[(hash + i) % GPR_ARRAY_SIZE(static_metadata_hash)];
-    if (ent.hash == hash && ent.idx < GRPC_STATIC_MDSTR_COUNT &&
-        grpc_slice_eq(grpc_static_slice_table[ent.idx], slice)) {
-      return grpc_static_slice_table[ent.idx];
-    }
-  }
-
-  interned_slice_refcount *s;
-  slice_shard *shard = &g_shards[SHARD_IDX(hash)];
-
-  gpr_mu_lock(&shard->mu);
-
-  /* search for an existing string */
-  size_t idx = TABLE_IDX(hash, shard->capacity);
-  for (s = shard->strs[idx]; s; s = s->bucket_next) {
-    if (s->hash == hash && grpc_slice_eq(slice, materialize(s))) {
-      if (gpr_atm_no_barrier_fetch_add(&s->refcnt, 1) == 0) {
-        /* If we get here, we've added a ref to something that was about to
-         * die - drop it immediately.
-         * The *only* possible path here (given the shard mutex) should be to
-         * drop from one ref back to zero - assert that with a CAS */
-        GPR_ASSERT(gpr_atm_rel_cas(&s->refcnt, 1, 0));
-        /* and treat this as if we were never here... sshhh */
-      } else {
-        gpr_mu_unlock(&shard->mu);
-        GPR_TIMER_END("grpc_mdstr_from_buffer", 0);
-        return materialize(s);
-      }
-    }
-  }
-
-  /* not found: create a new string */
-  /* string data goes after the internal_string header */
-  s = gpr_malloc(sizeof(*s) + GRPC_SLICE_LENGTH(slice));
-  gpr_atm_rel_store(&s->refcnt, 1);
-  s->length = GRPC_SLICE_LENGTH(slice);
-  s->hash = hash;
-  s->base.vtable = &interned_slice_vtable;
-  s->base.sub_refcount = &s->sub;
-  s->sub.vtable = &interned_slice_sub_vtable;
-  s->sub.sub_refcount = &s->sub;
-  s->bucket_next = shard->strs[idx];
-  shard->strs[idx] = s;
-  memcpy(s + 1, GRPC_SLICE_START_PTR(slice), GRPC_SLICE_LENGTH(slice));
-
-  shard->count++;
-
-  if (shard->count > shard->capacity * 2) {
-    grow_shard(shard);
-  }
-
-  gpr_mu_unlock(&shard->mu);
-
-  return materialize(s);
-}
-
-void grpc_test_only_set_slice_hash_seed(uint32_t seed) {
-  g_hash_seed = seed;
-  g_forced_hash_seed = 1;
-}
-
-void grpc_slice_intern_init(void) {
-  if (!g_forced_hash_seed) {
-    g_hash_seed = (uint32_t)gpr_now(GPR_CLOCK_REALTIME).tv_nsec;
-  }
-  for (size_t i = 0; i < SHARD_COUNT; i++) {
-    slice_shard *shard = &g_shards[i];
-    gpr_mu_init(&shard->mu);
-    shard->count = 0;
-    shard->capacity = INITIAL_SHARD_CAPACITY;
-    shard->strs = gpr_malloc(sizeof(*shard->strs) * shard->capacity);
-    memset(shard->strs, 0, sizeof(*shard->strs) * shard->capacity);
-  }
-  for (size_t i = 0; i < GPR_ARRAY_SIZE(static_metadata_hash); i++) {
-    static_metadata_hash[i].hash = 0;
-    static_metadata_hash[i].idx = GRPC_STATIC_MDSTR_COUNT;
-  }
-  max_static_metadata_hash_probe = 0;
-  for (size_t i = 0; i < GRPC_STATIC_MDSTR_COUNT; i++) {
-    static_metadata_hash_values[i] =
-        grpc_slice_default_hash_impl(grpc_static_slice_table[i]);
-    for (size_t j = 0; j < GPR_ARRAY_SIZE(static_metadata_hash); j++) {
-      size_t slot = (static_metadata_hash_values[i] + j) %
-                    GPR_ARRAY_SIZE(static_metadata_hash);
-      if (static_metadata_hash[slot].idx == GRPC_STATIC_MDSTR_COUNT) {
-        static_metadata_hash[slot].hash = static_metadata_hash_values[i];
-        static_metadata_hash[slot].idx = (uint32_t)i;
-        if (j > max_static_metadata_hash_probe) {
-          max_static_metadata_hash_probe = (uint32_t)j;
-        }
-        break;
-      }
-    }
-  }
-}
-
-void grpc_slice_intern_shutdown(void) {
-  for (size_t i = 0; i < SHARD_COUNT; i++) {
-    slice_shard *shard = &g_shards[i];
-    gpr_mu_destroy(&shard->mu);
-    /* TODO(ctiller): GPR_ASSERT(shard->count == 0); */
-    if (shard->count != 0) {
-      gpr_log(GPR_DEBUG, "WARNING: %" PRIuPTR " metadata strings were leaked",
-              shard->count);
-      for (size_t j = 0; j < shard->capacity; j++) {
-        for (interned_slice_refcount *s = shard->strs[j]; s;
-             s = s->bucket_next) {
-          char *text =
-              grpc_dump_slice(materialize(s), GPR_DUMP_HEX | GPR_DUMP_ASCII);
-          gpr_log(GPR_DEBUG, "LEAKED: %s", text);
-          gpr_free(text);
-        }
-      }
-      if (grpc_iomgr_abort_on_leaks()) {
-        abort();
-      }
-    }
-    gpr_free(shard->strs);
-  }
-}
diff --git a/src/core/lib/slice/slice_internal.h b/src/core/lib/slice/slice_internal.h
index 6467b0a8d6..6185333ca7 100644
--- a/src/core/lib/slice/slice_internal.h
+++ b/src/core/lib/slice/slice_internal.h
@@ -46,19 +46,4 @@ void grpc_slice_buffer_reset_and_unref_internal(grpc_exec_ctx *exec_ctx,
 void grpc_slice_buffer_destroy_internal(grpc_exec_ctx *exec_ctx,
                                         grpc_slice_buffer *sb);
 
-/* Check if a slice is interned */
-bool grpc_slice_is_interned(grpc_slice slice);
-
-void grpc_slice_intern_init(void);
-void grpc_slice_intern_shutdown(void);
-void grpc_test_only_set_slice_hash_seed(uint32_t key);
-// if slice matches a static slice, returns the static slice
-// otherwise returns the passed in slice (without reffing it)
-// used for surface boundaries where we might receive an un-interned static
-// string
-grpc_slice grpc_slice_maybe_static_intern(grpc_slice slice,
-                                          bool *returned_slice_is_different);
-uint32_t grpc_static_slice_hash(grpc_slice s);
-int grpc_static_slice_eq(grpc_slice a, grpc_slice b);
-
 #endif /* GRPC_CORE_LIB_SLICE_SLICE_INTERNAL_H */
diff --git a/src/core/lib/slice/slice_string_helpers.c b/src/core/lib/slice/slice_string_helpers.c
index 99695007cc..839c366b32 100644
--- a/src/core/lib/slice/slice_string_helpers.c
+++ b/src/core/lib/slice/slice_string_helpers.c
@@ -88,8 +88,3 @@ void grpc_slice_split(grpc_slice str, const char *sep, grpc_slice_buffer *dst) {
     grpc_slice_buffer_add_indexed(dst, grpc_slice_ref_internal(str));
   }
 }
-
-bool grpc_parse_slice_to_uint32(grpc_slice str, uint32_t *result) {
-  return gpr_parse_bytes_to_uint32((const char *)GRPC_SLICE_START_PTR(str),
-                                   GRPC_SLICE_LENGTH(str), result) != 0;
-}
diff --git a/src/core/lib/slice/slice_string_helpers.h b/src/core/lib/slice/slice_string_helpers.h
index 4a4deec6e5..151c720777 100644
--- a/src/core/lib/slice/slice_string_helpers.h
+++ b/src/core/lib/slice/slice_string_helpers.h
@@ -34,15 +34,12 @@
 #ifndef GRPC_CORE_LIB_SLICE_SLICE_STRING_HELPERS_H
 #define GRPC_CORE_LIB_SLICE_SLICE_STRING_HELPERS_H
 
-#include <stdbool.h>
 #include <stddef.h>
 
 #include <grpc/slice.h>
 #include <grpc/slice_buffer.h>
 #include <grpc/support/port_platform.h>
 
-#include "src/core/lib/support/string.h"
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -54,8 +51,6 @@ char *grpc_dump_slice(grpc_slice slice, uint32_t flags);
  * should be a properly initialized instance. */
 void grpc_slice_split(grpc_slice str, const char *sep, grpc_slice_buffer *dst);
 
-bool grpc_parse_slice_to_uint32(grpc_slice str, uint32_t *result);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/core/lib/slice/slice_traits.h b/src/core/lib/slice/slice_traits.h
deleted file mode 100644
index 8a283dc65c..0000000000
--- a/src/core/lib/slice/slice_traits.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- *
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_SLICE_SLICE_TRAITS_H
-#define GRPC_CORE_LIB_SLICE_SLICE_TRAITS_H
-
-#include <grpc/slice.h>
-#include <stdbool.h>
-
-bool grpc_slice_is_legal_header(grpc_slice s);
-bool grpc_slice_is_legal_nonbin_header(grpc_slice s);
-bool grpc_slice_is_bin_suffixed(grpc_slice s);
-
-#endif /* GRPC_CORE_LIB_SLICE_SLICE_TRAITS_H */
diff --git a/src/core/lib/surface/call.c b/src/core/lib/surface/call.c
index 63b0683df5..cac5737d91 100644
--- a/src/core/lib/surface/call.c
+++ b/src/core/lib/surface/call.c
@@ -56,15 +56,13 @@
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/surface/completion_queue.h"
-#include "src/core/lib/surface/validate_metadata.h"
-#include "src/core/lib/transport/error_utils.h"
 #include "src/core/lib/transport/metadata.h"
 #include "src/core/lib/transport/static_metadata.h"
 #include "src/core/lib/transport/transport.h"
 
 /** The maximum number of concurrent batches possible.
     Based upon the maximum number of individually queueable ops in the batch
-    api:
+   api:
       - initial metadata send
       - message send
       - status/close send (depending on client/server)
@@ -94,21 +92,18 @@ typedef enum {
 } status_source;
 
 typedef struct {
-  bool is_set;
-  grpc_error *error;
+  uint8_t is_set;
+  grpc_status_code code;
+  grpc_mdstr *details;
 } received_status;
 
-#define MAX_ERRORS_PER_BATCH 3
-
 typedef struct batch_control {
   grpc_call *call;
   grpc_cq_completion cq_completion;
   grpc_closure finish_batch;
   void *notify_tag;
   gpr_refcount steps_to_complete;
-
-  grpc_error *errors[MAX_ERRORS_PER_BATCH];
-  gpr_atm num_errors;
+  grpc_error *error;
 
   uint8_t send_initial_metadata;
   uint8_t send_message;
@@ -190,7 +185,6 @@ struct grpc_call {
   grpc_call *sibling_prev;
 
   grpc_slice_buffer_stream sending_stream;
-
   grpc_byte_stream *receiving_stream;
   grpc_byte_buffer **receiving_buffer;
   grpc_slice receiving_slice;
@@ -202,7 +196,8 @@ struct grpc_call {
   union {
     struct {
       grpc_status_code *status;
-      grpc_slice *status_details;
+      char **status_details;
+      size_t *status_details_capacity;
     } client;
     struct {
       int *cancelled;
@@ -224,23 +219,13 @@ static void execute_op(grpc_exec_ctx *exec_ctx, grpc_call *call,
 static grpc_call_error cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
                                           grpc_status_code status,
                                           const char *description);
-static void cancel_with_error(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                              grpc_error *error);
+static grpc_call_error close_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                                         grpc_status_code status,
+                                         const char *description);
 static void destroy_call(grpc_exec_ctx *exec_ctx, void *call_stack,
                          grpc_error *error);
 static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
                                   grpc_error *error);
-static void get_final_status(grpc_call *call,
-                             void (*set_value)(grpc_status_code code,
-                                               void *user_data),
-                             void *set_value_user_data, grpc_slice *details);
-static void set_status_value_directly(grpc_status_code status, void *dest);
-static void set_status_from_error(grpc_exec_ctx *exec_ctx, grpc_call *call,
-                                  status_source source, grpc_error *error);
-static void process_data_after_md(grpc_exec_ctx *exec_ctx, batch_control *bctl);
-static void post_batch_completion(grpc_exec_ctx *exec_ctx, batch_control *bctl);
-static void add_batch_error(grpc_exec_ctx *exec_ctx, batch_control *bctl,
-                            grpc_error *error);
 
 grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
                              const grpc_call_create_args *args,
@@ -261,16 +246,14 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
   /* Always support no compression */
   GPR_BITSET(&call->encodings_accepted_by_peer, GRPC_COMPRESS_NONE);
   call->is_client = args->server_transport_data == NULL;
-  grpc_slice path = grpc_empty_slice();
+  grpc_mdstr *path = NULL;
   if (call->is_client) {
     GPR_ASSERT(args->add_initial_metadata_count <
                MAX_SEND_EXTRA_METADATA_COUNT);
     for (i = 0; i < args->add_initial_metadata_count; i++) {
       call->send_extra_metadata[i].md = args->add_initial_metadata[i];
-      if (grpc_slice_eq(GRPC_MDKEY(args->add_initial_metadata[i]),
-                        GRPC_MDSTR_PATH)) {
-        path = grpc_slice_ref_internal(
-            GRPC_MDVALUE(args->add_initial_metadata[i]));
+      if (args->add_initial_metadata[i]->key == GRPC_MDSTR_PATH) {
+        path = GRPC_MDSTR_REF(args->add_initial_metadata[i]->value);
       }
     }
     call->send_extra_metadata_count = (int)args->add_initial_metadata_count;
@@ -337,7 +320,10 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
       args->server_transport_data, path, call->start_time, send_deadline,
       CALL_STACK_FROM_CALL(call));
   if (error != GRPC_ERROR_NONE) {
-    cancel_with_error(exec_ctx, call, GRPC_ERROR_REF(error));
+    grpc_status_code status;
+    const char *error_str;
+    grpc_error_get_status(error, &status, &error_str);
+    close_with_status(exec_ctx, call, status, error_str);
   }
   if (args->cq != NULL) {
     GPR_ASSERT(
@@ -356,7 +342,7 @@ grpc_error *grpc_call_create(grpc_exec_ctx *exec_ctx,
         exec_ctx, CALL_STACK_FROM_CALL(call), &call->pollent);
   }
 
-  grpc_slice_unref_internal(exec_ctx, path);
+  if (path != NULL) GRPC_MDSTR_UNREF(exec_ctx, path);
 
   GPR_TIMER_END("grpc_call_create", 0);
   return error;
@@ -391,6 +377,24 @@ void grpc_call_internal_unref(grpc_exec_ctx *exec_ctx, grpc_call *c REF_ARG) {
   GRPC_CALL_STACK_UNREF(exec_ctx, CALL_STACK_FROM_CALL(c), REF_REASON);
 }
 
+static void get_final_status(grpc_call *call,
+                             void (*set_value)(grpc_status_code code,
+                                               void *user_data),
+                             void *set_value_user_data) {
+  int i;
+  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+    if (call->status[i].is_set) {
+      set_value(call->status[i].code, set_value_user_data);
+      return;
+    }
+  }
+  if (call->is_client) {
+    set_value(GRPC_STATUS_UNKNOWN, set_value_user_data);
+  } else {
+    set_value(GRPC_STATUS_OK, set_value_user_data);
+  }
+}
+
 static void set_status_value_directly(grpc_status_code status, void *dest);
 static void destroy_call(grpc_exec_ctx *exec_ctx, void *call,
                          grpc_error *error) {
@@ -406,6 +410,11 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call,
     grpc_byte_stream_destroy(exec_ctx, c->receiving_stream);
   }
   gpr_mu_destroy(&c->mu);
+  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+    if (c->status[i].details) {
+      GRPC_MDSTR_UNREF(exec_ctx, c->status[i].details);
+    }
+  }
   for (ii = 0; ii < c->send_extra_metadata_count; ii++) {
     GRPC_MDELEM_UNREF(exec_ctx, c->send_extra_metadata[ii].md);
   }
@@ -419,245 +428,42 @@ static void destroy_call(grpc_exec_ctx *exec_ctx, void *call,
   }
   grpc_channel *channel = c->channel;
 
-  get_final_status(call, set_status_value_directly, &c->final_info.final_status,
-                   NULL);
+  get_final_status(call, set_status_value_directly,
+                   &c->final_info.final_status);
   c->final_info.stats.latency =
       gpr_time_sub(gpr_now(GPR_CLOCK_MONOTONIC), c->start_time);
 
-  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
-    GRPC_ERROR_UNREF(c->status[i].error);
-  }
-
   grpc_call_stack_destroy(exec_ctx, CALL_STACK_FROM_CALL(c), &c->final_info, c);
   GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, channel, "call");
   GPR_TIMER_END("destroy_call", 0);
 }
 
-void grpc_call_destroy(grpc_call *c) {
-  int cancel;
-  grpc_call *parent = c->parent;
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-
-  GPR_TIMER_BEGIN("grpc_call_destroy", 0);
-  GRPC_API_TRACE("grpc_call_destroy(c=%p)", 1, (c));
-
-  if (parent) {
-    gpr_mu_lock(&parent->mu);
-    if (c == parent->first_child) {
-      parent->first_child = c->sibling_next;
-      if (c == parent->first_child) {
-        parent->first_child = NULL;
-      }
-      c->sibling_prev->sibling_next = c->sibling_next;
-      c->sibling_next->sibling_prev = c->sibling_prev;
-    }
-    gpr_mu_unlock(&parent->mu);
-    GRPC_CALL_INTERNAL_UNREF(&exec_ctx, parent, "child");
-  }
-
-  gpr_mu_lock(&c->mu);
-  GPR_ASSERT(!c->destroy_called);
-  c->destroy_called = 1;
-  cancel = !c->received_final_op;
-  gpr_mu_unlock(&c->mu);
-  if (cancel) grpc_call_cancel(c, NULL);
-  GRPC_CALL_INTERNAL_UNREF(&exec_ctx, c, "destroy");
-  grpc_exec_ctx_finish(&exec_ctx);
-  GPR_TIMER_END("grpc_call_destroy", 0);
-}
-
-grpc_call_error grpc_call_cancel(grpc_call *call, void *reserved) {
-  GRPC_API_TRACE("grpc_call_cancel(call=%p, reserved=%p)", 2, (call, reserved));
-  GPR_ASSERT(!reserved);
-  return grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED, "Cancelled",
-                                      NULL);
-}
-
-static void execute_op(grpc_exec_ctx *exec_ctx, grpc_call *call,
-                       grpc_transport_stream_op *op) {
-  grpc_call_element *elem;
-
-  GPR_TIMER_BEGIN("execute_op", 0);
-  elem = CALL_ELEM_FROM_CALL(call, 0);
-  op->context = call->context;
-  elem->filter->start_transport_stream_op(exec_ctx, elem, op);
-  GPR_TIMER_END("execute_op", 0);
-}
-
-char *grpc_call_get_peer(grpc_call *call) {
-  grpc_call_element *elem = CALL_ELEM_FROM_CALL(call, 0);
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  char *result;
-  GRPC_API_TRACE("grpc_call_get_peer(%p)", 1, (call));
-  result = elem->filter->get_peer(&exec_ctx, elem);
-  if (result == NULL) {
-    result = grpc_channel_get_target(call->channel);
-  }
-  if (result == NULL) {
-    result = gpr_strdup("unknown");
-  }
-  grpc_exec_ctx_finish(&exec_ctx);
-  return result;
-}
-
-grpc_call *grpc_call_from_top_element(grpc_call_element *elem) {
-  return CALL_FROM_TOP_ELEM(elem);
-}
-
-/*******************************************************************************
- * CANCELLATION
- */
-
-grpc_call_error grpc_call_cancel_with_status(grpc_call *c,
-                                             grpc_status_code status,
-                                             const char *description,
-                                             void *reserved) {
-  grpc_call_error r;
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  GRPC_API_TRACE(
-      "grpc_call_cancel_with_status("
-      "c=%p, status=%d, description=%s, reserved=%p)",
-      4, (c, (int)status, description, reserved));
-  GPR_ASSERT(reserved == NULL);
-  gpr_mu_lock(&c->mu);
-  r = cancel_with_status(&exec_ctx, c, status, description);
-  gpr_mu_unlock(&c->mu);
-  grpc_exec_ctx_finish(&exec_ctx);
-  return r;
-}
-
-typedef struct termination_closure {
-  grpc_closure closure;
-  grpc_call *call;
-  grpc_error *error;
-  grpc_transport_stream_op op;
-} termination_closure;
-
-static void done_termination(grpc_exec_ctx *exec_ctx, void *tcp,
-                             grpc_error *error) {
-  termination_closure *tc = tcp;
-  GRPC_CALL_INTERNAL_UNREF(exec_ctx, tc->call, "termination");
-  gpr_free(tc);
-}
-
-static void send_termination(grpc_exec_ctx *exec_ctx, void *tcp,
-                             grpc_error *error) {
-  termination_closure *tc = tcp;
-  memset(&tc->op, 0, sizeof(tc->op));
-  tc->op.cancel_error = tc->error;
-  /* reuse closure to catch completion */
-  grpc_closure_init(&tc->closure, done_termination, tc,
-                    grpc_schedule_on_exec_ctx);
-  tc->op.on_complete = &tc->closure;
-  execute_op(exec_ctx, tc->call, &tc->op);
-}
-
-static grpc_call_error terminate_with_status(grpc_exec_ctx *exec_ctx,
-                                             termination_closure *tc) {
-  set_status_from_error(exec_ctx, tc->call, STATUS_FROM_API_OVERRIDE,
-                        GRPC_ERROR_REF(tc->error));
-  grpc_closure_init(&tc->closure, send_termination, tc,
-                    grpc_schedule_on_exec_ctx);
-  GRPC_CALL_INTERNAL_REF(tc->call, "termination");
-  grpc_closure_sched(exec_ctx, &tc->closure, GRPC_ERROR_NONE);
-  return GRPC_CALL_OK;
-}
-
-static grpc_call_error terminate_with_error(grpc_exec_ctx *exec_ctx,
-                                            grpc_call *c, grpc_error *error) {
-  termination_closure *tc = gpr_malloc(sizeof(*tc));
-  memset(tc, 0, sizeof(*tc));
-  tc->call = c;
-  tc->error = error;
-  return terminate_with_status(exec_ctx, tc);
-}
+static void set_status_code(grpc_call *call, status_source source,
+                            uint32_t status) {
+  if (call->status[source].is_set) return;
 
-static void cancel_with_error(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                              grpc_error *error) {
-  terminate_with_error(exec_ctx, c, error);
+  call->status[source].is_set = 1;
+  call->status[source].code = (grpc_status_code)status;
 }
 
-static grpc_error *error_from_status(grpc_status_code status,
-                                     const char *description) {
-  return grpc_error_set_int(
-      grpc_error_set_str(GRPC_ERROR_CREATE(description),
-                         GRPC_ERROR_STR_GRPC_MESSAGE, description),
-      GRPC_ERROR_INT_GRPC_STATUS, status);
-}
-
-static grpc_call_error cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
-                                          grpc_status_code status,
-                                          const char *description) {
-  return terminate_with_error(exec_ctx, c,
-                              error_from_status(status, description));
-}
-
-/*******************************************************************************
- * FINAL STATUS CODE MANIPULATION
- */
-
-static void get_final_status_from(grpc_call *call, status_source from_source,
-                                  void (*set_value)(grpc_status_code code,
-                                                    void *user_data),
-                                  void *set_value_user_data,
-                                  grpc_slice *details) {
-  grpc_status_code code;
-  const char *msg = NULL;
-  grpc_error_get_status(call->status[from_source].error, call->send_deadline,
-                        &code, &msg, NULL);
-
-  set_value(code, set_value_user_data);
-  if (details != NULL) {
-    *details =
-        msg == NULL ? grpc_empty_slice() : grpc_slice_from_copied_string(msg);
-  }
-}
-
-static void get_final_status(grpc_call *call,
-                             void (*set_value)(grpc_status_code code,
-                                               void *user_data),
-                             void *set_value_user_data, grpc_slice *details) {
-  int i;
-  /* search for the best status we can present: ideally the error we use has a
-     clearly defined grpc-status, and we'll prefer that. */
-  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
-    if (call->status[i].is_set &&
-        grpc_error_has_clear_grpc_status(call->status[i].error)) {
-      get_final_status_from(call, (status_source)i, set_value,
-                            set_value_user_data, details);
-      return;
-    }
-  }
-  /* If no clearly defined status exists, search for 'anything' */
-  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
-    if (call->status[i].is_set) {
-      get_final_status_from(call, (status_source)i, set_value,
-                            set_value_user_data, details);
-      return;
-    }
-  }
-  /* If nothing exists, set some default */
-  if (call->is_client) {
-    set_value(GRPC_STATUS_UNKNOWN, set_value_user_data);
+static void set_status_details(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                               status_source source, grpc_mdstr *status) {
+  if (call->status[source].details != NULL) {
+    GRPC_MDSTR_UNREF(exec_ctx, status);
   } else {
-    set_value(GRPC_STATUS_OK, set_value_user_data);
+    call->status[source].details = status;
   }
 }
 
 static void set_status_from_error(grpc_exec_ctx *exec_ctx, grpc_call *call,
                                   status_source source, grpc_error *error) {
-  if (call->status[source].is_set) {
-    GRPC_ERROR_UNREF(error);
-    return;
-  }
-  call->status[source].is_set = true;
-  call->status[source].error = error;
+  grpc_status_code status;
+  const char *msg;
+  grpc_error_get_status(error, &status, &msg);
+  set_status_code(call, source, (uint32_t)status);
+  set_status_details(exec_ctx, call, source, grpc_mdstr_from_string(msg));
 }
 
-/*******************************************************************************
- * COMPRESSION
- */
-
 static void set_incoming_compression_algorithm(
     grpc_call *call, grpc_compression_algorithm algo) {
   GPR_ASSERT(algo < GRPC_COMPRESS_ALGORITHMS_COUNT);
@@ -690,7 +496,7 @@ uint32_t grpc_call_test_only_get_message_flags(grpc_call *call) {
 static void destroy_encodings_accepted_by_peer(void *p) { return; }
 
 static void set_encodings_accepted_by_peer(grpc_exec_ctx *exec_ctx,
-                                           grpc_call *call, grpc_mdelem mdel) {
+                                           grpc_call *call, grpc_mdelem *mdel) {
   size_t i;
   grpc_compression_algorithm algorithm;
   grpc_slice_buffer accept_encoding_parts;
@@ -705,7 +511,7 @@ static void set_encodings_accepted_by_peer(grpc_exec_ctx *exec_ctx,
     return;
   }
 
-  accept_encoding_slice = GRPC_MDVALUE(mdel);
+  accept_encoding_slice = mdel->value->slice;
   grpc_slice_buffer_init(&accept_encoding_parts);
   grpc_slice_split(accept_encoding_slice, ",", &accept_encoding_parts);
 
@@ -714,13 +520,15 @@ static void set_encodings_accepted_by_peer(grpc_exec_ctx *exec_ctx,
   /* Always support no compression */
   GPR_BITSET(&call->encodings_accepted_by_peer, GRPC_COMPRESS_NONE);
   for (i = 0; i < accept_encoding_parts.count; i++) {
-    grpc_slice accept_encoding_entry_slice = accept_encoding_parts.slices[i];
-    if (grpc_compression_algorithm_parse(accept_encoding_entry_slice,
-                                         &algorithm)) {
+    const grpc_slice *accept_encoding_entry_slice =
+        &accept_encoding_parts.slices[i];
+    if (grpc_compression_algorithm_parse(
+            (const char *)GRPC_SLICE_START_PTR(*accept_encoding_entry_slice),
+            GRPC_SLICE_LENGTH(*accept_encoding_entry_slice), &algorithm)) {
       GPR_BITSET(&call->encodings_accepted_by_peer, algorithm);
     } else {
       char *accept_encoding_entry_str =
-          grpc_slice_to_c_string(accept_encoding_entry_slice);
+          grpc_dump_slice(*accept_encoding_entry_slice, GPR_DUMP_ASCII);
       gpr_log(GPR_ERROR,
               "Invalid entry in accept encoding metadata: '%s'. Ignoring.",
               accept_encoding_entry_str);
@@ -743,6 +551,36 @@ uint32_t grpc_call_test_only_get_encodings_accepted_by_peer(grpc_call *call) {
   return encodings_accepted_by_peer;
 }
 
+static void get_final_details(grpc_call *call, char **out_details,
+                              size_t *out_details_capacity) {
+  int i;
+  for (i = 0; i < STATUS_SOURCE_COUNT; i++) {
+    if (call->status[i].is_set) {
+      if (call->status[i].details) {
+        grpc_slice details = call->status[i].details->slice;
+        size_t len = GRPC_SLICE_LENGTH(details);
+        if (len + 1 > *out_details_capacity) {
+          *out_details_capacity =
+              GPR_MAX(len + 1, *out_details_capacity * 3 / 2);
+          *out_details = gpr_realloc(*out_details, *out_details_capacity);
+        }
+        memcpy(*out_details, GRPC_SLICE_START_PTR(details), len);
+        (*out_details)[len] = 0;
+      } else {
+        goto no_details;
+      }
+      return;
+    }
+  }
+
+no_details:
+  if (0 == *out_details_capacity) {
+    *out_details_capacity = 8;
+    *out_details = gpr_malloc(*out_details_capacity);
+  }
+  **out_details = 0;
+}
+
 static grpc_linked_mdelem *linked_from_md(grpc_metadata *md) {
   return (grpc_linked_mdelem *)&md->internal_data;
 }
@@ -769,19 +607,24 @@ static int prepare_application_metadata(
         get_md_elem(metadata, additional_metadata, i, count);
     grpc_linked_mdelem *l = (grpc_linked_mdelem *)&md->internal_data;
     GPR_ASSERT(sizeof(grpc_linked_mdelem) == sizeof(md->internal_data));
-    if (!GRPC_LOG_IF_ERROR("validate_metadata",
-                           grpc_validate_header_key_is_legal(md->key))) {
+    l->md = grpc_mdelem_from_string_and_buffer(
+        exec_ctx, md->key, (const uint8_t *)md->value, md->value_length);
+    if (!grpc_header_key_is_legal(grpc_mdstr_as_c_string(l->md->key),
+                                  GRPC_MDSTR_LENGTH(l->md->key))) {
+      gpr_log(GPR_ERROR, "attempt to send invalid metadata key: %s",
+              grpc_mdstr_as_c_string(l->md->key));
       break;
-    } else if (!grpc_is_binary_header(md->key) &&
-               !GRPC_LOG_IF_ERROR(
-                   "validate_metadata",
-                   grpc_validate_header_nonbin_value_is_legal(md->value))) {
+    } else if (!grpc_is_binary_header(grpc_mdstr_as_c_string(l->md->key),
+                                      GRPC_MDSTR_LENGTH(l->md->key)) &&
+               !grpc_header_nonbin_value_is_legal(
+                   grpc_mdstr_as_c_string(l->md->value),
+                   GRPC_MDSTR_LENGTH(l->md->value))) {
+      gpr_log(GPR_ERROR, "attempt to send invalid metadata value");
       break;
     }
-    l->md = grpc_mdelem_from_grpc_metadata(exec_ctx, (grpc_metadata *)md);
   }
   if (i != total_count) {
-    for (int j = 0; j < i; j++) {
+    for (int j = 0; j <= i; j++) {
       const grpc_metadata *md =
           get_md_elem(metadata, additional_metadata, j, count);
       grpc_linked_mdelem *l = (grpc_linked_mdelem *)&md->internal_data;
@@ -793,41 +636,278 @@ static int prepare_application_metadata(
     if (call->send_extra_metadata_count == 0) {
       prepend_extra_metadata = 0;
     } else {
-      for (i = 0; i < call->send_extra_metadata_count; i++) {
-        GRPC_LOG_IF_ERROR("prepare_application_metadata",
-                          grpc_metadata_batch_link_tail(
-                              exec_ctx, batch, &call->send_extra_metadata[i]));
+      for (i = 1; i < call->send_extra_metadata_count; i++) {
+        call->send_extra_metadata[i].prev = &call->send_extra_metadata[i - 1];
+      }
+      for (i = 0; i < call->send_extra_metadata_count - 1; i++) {
+        call->send_extra_metadata[i].next = &call->send_extra_metadata[i + 1];
       }
     }
   }
-  for (i = 0; i < total_count; i++) {
+  for (i = 1; i < total_count; i++) {
+    grpc_metadata *md = get_md_elem(metadata, additional_metadata, i, count);
+    grpc_metadata *prev_md =
+        get_md_elem(metadata, additional_metadata, i - 1, count);
+    linked_from_md(md)->prev = linked_from_md(prev_md);
+  }
+  for (i = 0; i < total_count - 1; i++) {
     grpc_metadata *md = get_md_elem(metadata, additional_metadata, i, count);
-    GRPC_LOG_IF_ERROR(
-        "prepare_application_metadata",
-        grpc_metadata_batch_link_tail(exec_ctx, batch, linked_from_md(md)));
+    grpc_metadata *next_md =
+        get_md_elem(metadata, additional_metadata, i + 1, count);
+    linked_from_md(md)->next = linked_from_md(next_md);
+  }
+
+  switch (prepend_extra_metadata * 2 + (total_count != 0)) {
+    case 0:
+      /* no prepend, no metadata => nothing to do */
+      batch->list.head = batch->list.tail = NULL;
+      break;
+    case 1: {
+      /* metadata, but no prepend */
+      grpc_metadata *first_md =
+          get_md_elem(metadata, additional_metadata, 0, count);
+      grpc_metadata *last_md =
+          get_md_elem(metadata, additional_metadata, total_count - 1, count);
+      batch->list.head = linked_from_md(first_md);
+      batch->list.tail = linked_from_md(last_md);
+      batch->list.head->prev = NULL;
+      batch->list.tail->next = NULL;
+      break;
+    }
+    case 2:
+      /* prepend, but no md */
+      batch->list.head = &call->send_extra_metadata[0];
+      batch->list.tail =
+          &call->send_extra_metadata[call->send_extra_metadata_count - 1];
+      batch->list.head->prev = NULL;
+      batch->list.tail->next = NULL;
+      call->send_extra_metadata_count = 0;
+      break;
+    case 3: {
+      /* prepend AND md */
+      grpc_metadata *first_md =
+          get_md_elem(metadata, additional_metadata, 0, count);
+      grpc_metadata *last_md =
+          get_md_elem(metadata, additional_metadata, total_count - 1, count);
+      batch->list.head = &call->send_extra_metadata[0];
+      call->send_extra_metadata[call->send_extra_metadata_count - 1].next =
+          linked_from_md(first_md);
+      linked_from_md(first_md)->prev =
+          &call->send_extra_metadata[call->send_extra_metadata_count - 1];
+      batch->list.tail = linked_from_md(last_md);
+      batch->list.head->prev = NULL;
+      batch->list.tail->next = NULL;
+      call->send_extra_metadata_count = 0;
+      break;
+    }
+    default:
+      GPR_UNREACHABLE_CODE(return 0);
   }
-  call->send_extra_metadata_count = 0;
 
   return 1;
 }
 
+void grpc_call_destroy(grpc_call *c) {
+  int cancel;
+  grpc_call *parent = c->parent;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+
+  GPR_TIMER_BEGIN("grpc_call_destroy", 0);
+  GRPC_API_TRACE("grpc_call_destroy(c=%p)", 1, (c));
+
+  if (parent) {
+    gpr_mu_lock(&parent->mu);
+    if (c == parent->first_child) {
+      parent->first_child = c->sibling_next;
+      if (c == parent->first_child) {
+        parent->first_child = NULL;
+      }
+      c->sibling_prev->sibling_next = c->sibling_next;
+      c->sibling_next->sibling_prev = c->sibling_prev;
+    }
+    gpr_mu_unlock(&parent->mu);
+    GRPC_CALL_INTERNAL_UNREF(&exec_ctx, parent, "child");
+  }
+
+  gpr_mu_lock(&c->mu);
+  GPR_ASSERT(!c->destroy_called);
+  c->destroy_called = 1;
+  cancel = !c->received_final_op;
+  gpr_mu_unlock(&c->mu);
+  if (cancel) grpc_call_cancel(c, NULL);
+  GRPC_CALL_INTERNAL_UNREF(&exec_ctx, c, "destroy");
+  grpc_exec_ctx_finish(&exec_ctx);
+  GPR_TIMER_END("grpc_call_destroy", 0);
+}
+
+grpc_call_error grpc_call_cancel(grpc_call *call, void *reserved) {
+  GRPC_API_TRACE("grpc_call_cancel(call=%p, reserved=%p)", 2, (call, reserved));
+  GPR_ASSERT(!reserved);
+  return grpc_call_cancel_with_status(call, GRPC_STATUS_CANCELLED, "Cancelled",
+                                      NULL);
+}
+
+grpc_call_error grpc_call_cancel_with_status(grpc_call *c,
+                                             grpc_status_code status,
+                                             const char *description,
+                                             void *reserved) {
+  grpc_call_error r;
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  GRPC_API_TRACE(
+      "grpc_call_cancel_with_status("
+      "c=%p, status=%d, description=%s, reserved=%p)",
+      4, (c, (int)status, description, reserved));
+  GPR_ASSERT(reserved == NULL);
+  gpr_mu_lock(&c->mu);
+  r = cancel_with_status(&exec_ctx, c, status, description);
+  gpr_mu_unlock(&c->mu);
+  grpc_exec_ctx_finish(&exec_ctx);
+  return r;
+}
+
+typedef struct termination_closure {
+  grpc_closure closure;
+  grpc_call *call;
+  grpc_error *error;
+  enum { TC_CANCEL, TC_CLOSE } type;
+  grpc_transport_stream_op op;
+} termination_closure;
+
+static void done_termination(grpc_exec_ctx *exec_ctx, void *tcp,
+                             grpc_error *error) {
+  termination_closure *tc = tcp;
+  switch (tc->type) {
+    case TC_CANCEL:
+      GRPC_CALL_INTERNAL_UNREF(exec_ctx, tc->call, "cancel");
+      break;
+    case TC_CLOSE:
+      GRPC_CALL_INTERNAL_UNREF(exec_ctx, tc->call, "close");
+      break;
+  }
+  GRPC_ERROR_UNREF(tc->error);
+  gpr_free(tc);
+}
+
+static void send_cancel(grpc_exec_ctx *exec_ctx, void *tcp, grpc_error *error) {
+  termination_closure *tc = tcp;
+  memset(&tc->op, 0, sizeof(tc->op));
+  tc->op.cancel_error = tc->error;
+  /* reuse closure to catch completion */
+  grpc_closure_init(&tc->closure, done_termination, tc,
+                    grpc_schedule_on_exec_ctx);
+  tc->op.on_complete = &tc->closure;
+  execute_op(exec_ctx, tc->call, &tc->op);
+}
+
+static void send_close(grpc_exec_ctx *exec_ctx, void *tcp, grpc_error *error) {
+  termination_closure *tc = tcp;
+  memset(&tc->op, 0, sizeof(tc->op));
+  tc->op.close_error = tc->error;
+  /* reuse closure to catch completion */
+  grpc_closure_init(&tc->closure, done_termination, tc,
+                    grpc_schedule_on_exec_ctx);
+  tc->op.on_complete = &tc->closure;
+  execute_op(exec_ctx, tc->call, &tc->op);
+}
+
+static grpc_call_error terminate_with_status(grpc_exec_ctx *exec_ctx,
+                                             termination_closure *tc) {
+  set_status_from_error(exec_ctx, tc->call, STATUS_FROM_API_OVERRIDE,
+                        tc->error);
+
+  if (tc->type == TC_CANCEL) {
+    grpc_closure_init(&tc->closure, send_cancel, tc, grpc_schedule_on_exec_ctx);
+    GRPC_CALL_INTERNAL_REF(tc->call, "cancel");
+  } else if (tc->type == TC_CLOSE) {
+    grpc_closure_init(&tc->closure, send_close, tc, grpc_schedule_on_exec_ctx);
+    GRPC_CALL_INTERNAL_REF(tc->call, "close");
+  }
+  grpc_closure_sched(exec_ctx, &tc->closure, GRPC_ERROR_NONE);
+  return GRPC_CALL_OK;
+}
+
+static grpc_call_error cancel_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                                          grpc_status_code status,
+                                          const char *description) {
+  GPR_ASSERT(status != GRPC_STATUS_OK);
+  termination_closure *tc = gpr_malloc(sizeof(*tc));
+  memset(tc, 0, sizeof(termination_closure));
+  tc->type = TC_CANCEL;
+  tc->call = c;
+  tc->error = grpc_error_set_int(
+      grpc_error_set_str(GRPC_ERROR_CREATE(description),
+                         GRPC_ERROR_STR_GRPC_MESSAGE, description),
+      GRPC_ERROR_INT_GRPC_STATUS, status);
+
+  return terminate_with_status(exec_ctx, tc);
+}
+
+static grpc_call_error close_with_status(grpc_exec_ctx *exec_ctx, grpc_call *c,
+                                         grpc_status_code status,
+                                         const char *description) {
+  GPR_ASSERT(status != GRPC_STATUS_OK);
+  termination_closure *tc = gpr_malloc(sizeof(*tc));
+  memset(tc, 0, sizeof(termination_closure));
+  tc->type = TC_CLOSE;
+  tc->call = c;
+  tc->error = grpc_error_set_int(
+      grpc_error_set_str(GRPC_ERROR_CREATE(description),
+                         GRPC_ERROR_STR_GRPC_MESSAGE, description),
+      GRPC_ERROR_INT_GRPC_STATUS, status);
+
+  return terminate_with_status(exec_ctx, tc);
+}
+
+static void execute_op(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                       grpc_transport_stream_op *op) {
+  grpc_call_element *elem;
+
+  GPR_TIMER_BEGIN("execute_op", 0);
+  elem = CALL_ELEM_FROM_CALL(call, 0);
+  op->context = call->context;
+  elem->filter->start_transport_stream_op(exec_ctx, elem, op);
+  GPR_TIMER_END("execute_op", 0);
+}
+
+char *grpc_call_get_peer(grpc_call *call) {
+  grpc_call_element *elem = CALL_ELEM_FROM_CALL(call, 0);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  char *result;
+  GRPC_API_TRACE("grpc_call_get_peer(%p)", 1, (call));
+  result = elem->filter->get_peer(&exec_ctx, elem);
+  if (result == NULL) {
+    result = grpc_channel_get_target(call->channel);
+  }
+  if (result == NULL) {
+    result = gpr_strdup("unknown");
+  }
+  grpc_exec_ctx_finish(&exec_ctx);
+  return result;
+}
+
+grpc_call *grpc_call_from_top_element(grpc_call_element *elem) {
+  return CALL_FROM_TOP_ELEM(elem);
+}
+
 /* we offset status by a small amount when storing it into transport metadata
    as metadata cannot store a 0 value (which is used as OK for grpc_status_codes
    */
 #define STATUS_OFFSET 1
 static void destroy_status(void *ignored) {}
 
-static uint32_t decode_status(grpc_mdelem md) {
+static uint32_t decode_status(grpc_mdelem *md) {
   uint32_t status;
   void *user_data;
-  if (grpc_mdelem_eq(md, GRPC_MDELEM_GRPC_STATUS_0)) return 0;
-  if (grpc_mdelem_eq(md, GRPC_MDELEM_GRPC_STATUS_1)) return 1;
-  if (grpc_mdelem_eq(md, GRPC_MDELEM_GRPC_STATUS_2)) return 2;
+  if (md == GRPC_MDELEM_GRPC_STATUS_0) return 0;
+  if (md == GRPC_MDELEM_GRPC_STATUS_1) return 1;
+  if (md == GRPC_MDELEM_GRPC_STATUS_2) return 2;
   user_data = grpc_mdelem_get_user_data(md, destroy_status);
   if (user_data != NULL) {
     status = ((uint32_t)(intptr_t)user_data) - STATUS_OFFSET;
   } else {
-    if (!grpc_parse_slice_to_uint32(GRPC_MDVALUE(md), &status)) {
+    if (!gpr_parse_bytes_to_uint32(grpc_mdstr_as_c_string(md->value),
+                                   GRPC_SLICE_LENGTH(md->value->slice),
+                                   &status)) {
       status = GRPC_STATUS_UNKNOWN; /* could not parse status code */
     }
     grpc_mdelem_set_user_data(md, destroy_status,
@@ -836,104 +916,93 @@ static uint32_t decode_status(grpc_mdelem md) {
   return status;
 }
 
-static grpc_compression_algorithm decode_compression(grpc_mdelem md) {
+static grpc_compression_algorithm decode_compression(grpc_mdelem *md) {
   grpc_compression_algorithm algorithm =
-      grpc_compression_algorithm_from_slice(GRPC_MDVALUE(md));
+      grpc_compression_algorithm_from_mdstr(md->value);
   if (algorithm == GRPC_COMPRESS_ALGORITHMS_COUNT) {
-    char *md_c_str = grpc_slice_to_c_string(GRPC_MDVALUE(md));
+    const char *md_c_str = grpc_mdstr_as_c_string(md->value);
     gpr_log(GPR_ERROR,
             "Invalid incoming compression algorithm: '%s'. Interpreting "
             "incoming data as uncompressed.",
             md_c_str);
-    gpr_free(md_c_str);
     return GRPC_COMPRESS_NONE;
   }
   return algorithm;
 }
 
-static void recv_common_filter(grpc_exec_ctx *exec_ctx, grpc_call *call,
-                               grpc_metadata_batch *b) {
-  if (b->idx.named.grpc_status != NULL) {
-    uint32_t status_code = decode_status(b->idx.named.grpc_status->md);
-    grpc_error *error =
-        status_code == GRPC_STATUS_OK
-            ? GRPC_ERROR_NONE
-            : grpc_error_set_int(GRPC_ERROR_CREATE("Error received from peer"),
-                                 GRPC_ERROR_INT_GRPC_STATUS,
-                                 (intptr_t)status_code);
-
-    if (b->idx.named.grpc_message != NULL) {
-      char *msg =
-          grpc_slice_to_c_string(GRPC_MDVALUE(b->idx.named.grpc_message->md));
-      error = grpc_error_set_str(error, GRPC_ERROR_STR_GRPC_MESSAGE, msg);
-      gpr_free(msg);
-      grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.grpc_message);
-    } else {
-      error = grpc_error_set_str(error, GRPC_ERROR_STR_GRPC_MESSAGE, "");
-    }
-
-    set_status_from_error(exec_ctx, call, STATUS_FROM_WIRE, error);
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.grpc_status);
-  }
+static grpc_mdelem *recv_common_filter(grpc_exec_ctx *exec_ctx, grpc_call *call,
+                                       grpc_mdelem *elem) {
+  if (elem->key == GRPC_MDSTR_GRPC_STATUS) {
+    GPR_TIMER_BEGIN("status", 0);
+    set_status_code(call, STATUS_FROM_WIRE, decode_status(elem));
+    GPR_TIMER_END("status", 0);
+    return NULL;
+  } else if (elem->key == GRPC_MDSTR_GRPC_MESSAGE) {
+    GPR_TIMER_BEGIN("status-details", 0);
+    set_status_details(exec_ctx, call, STATUS_FROM_WIRE,
+                       GRPC_MDSTR_REF(elem->value));
+    GPR_TIMER_END("status-details", 0);
+    return NULL;
+  }
+  return elem;
 }
 
-static void publish_app_metadata(grpc_call *call, grpc_metadata_batch *b,
-                                 int is_trailing) {
-  if (b->list.count == 0) return;
-  GPR_TIMER_BEGIN("publish_app_metadata", 0);
+static grpc_mdelem *publish_app_metadata(grpc_call *call, grpc_mdelem *elem,
+                                         int is_trailing) {
   grpc_metadata_array *dest;
   grpc_metadata *mdusr;
+  GPR_TIMER_BEGIN("publish_app_metadata", 0);
   dest = call->buffered_metadata[is_trailing];
-  if (dest->count + b->list.count > dest->capacity) {
-    dest->capacity =
-        GPR_MAX(dest->capacity + b->list.count, dest->capacity * 3 / 2);
+  if (dest->count == dest->capacity) {
+    dest->capacity = GPR_MAX(dest->capacity + 8, dest->capacity * 2);
     dest->metadata =
         gpr_realloc(dest->metadata, sizeof(grpc_metadata) * dest->capacity);
   }
-  for (grpc_linked_mdelem *l = b->list.head; l != NULL; l = l->next) {
-    mdusr = &dest->metadata[dest->count++];
-    /* we pass back borrowed slices that are valid whilst the call is valid */
-    mdusr->key = GRPC_MDKEY(l->md);
-    mdusr->value = GRPC_MDVALUE(l->md);
-  }
+  mdusr = &dest->metadata[dest->count++];
+  mdusr->key = grpc_mdstr_as_c_string(elem->key);
+  mdusr->value = grpc_mdstr_as_c_string(elem->value);
+  mdusr->value_length = GRPC_SLICE_LENGTH(elem->value->slice);
   GPR_TIMER_END("publish_app_metadata", 0);
+  return elem;
 }
 
-static void recv_initial_filter(grpc_exec_ctx *exec_ctx, grpc_call *call,
-                                grpc_metadata_batch *b) {
-  recv_common_filter(exec_ctx, call, b);
-
-  if (b->idx.named.grpc_encoding != NULL) {
+static grpc_mdelem *recv_initial_filter(grpc_exec_ctx *exec_ctx, void *args,
+                                        grpc_mdelem *elem) {
+  grpc_call *call = args;
+  elem = recv_common_filter(exec_ctx, call, elem);
+  if (elem == NULL) {
+    return NULL;
+  } else if (elem->key == GRPC_MDSTR_GRPC_ENCODING) {
     GPR_TIMER_BEGIN("incoming_compression_algorithm", 0);
-    set_incoming_compression_algorithm(
-        call, decode_compression(b->idx.named.grpc_encoding->md));
+    set_incoming_compression_algorithm(call, decode_compression(elem));
     GPR_TIMER_END("incoming_compression_algorithm", 0);
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.grpc_encoding);
-  }
-
-  if (b->idx.named.grpc_accept_encoding != NULL) {
+    return NULL;
+  } else if (elem->key == GRPC_MDSTR_GRPC_ACCEPT_ENCODING) {
     GPR_TIMER_BEGIN("encodings_accepted_by_peer", 0);
-    set_encodings_accepted_by_peer(exec_ctx, call,
-                                   b->idx.named.grpc_accept_encoding->md);
-    grpc_metadata_batch_remove(exec_ctx, b, b->idx.named.grpc_accept_encoding);
+    set_encodings_accepted_by_peer(exec_ctx, call, elem);
     GPR_TIMER_END("encodings_accepted_by_peer", 0);
+    return NULL;
+  } else {
+    return publish_app_metadata(call, elem, 0);
   }
-
-  publish_app_metadata(call, b, false);
 }
 
-static void recv_trailing_filter(grpc_exec_ctx *exec_ctx, void *args,
-                                 grpc_metadata_batch *b) {
+static grpc_mdelem *recv_trailing_filter(grpc_exec_ctx *exec_ctx, void *args,
+                                         grpc_mdelem *elem) {
   grpc_call *call = args;
-  recv_common_filter(exec_ctx, call, b);
-  publish_app_metadata(call, b, true);
+  elem = recv_common_filter(exec_ctx, call, elem);
+  if (elem == NULL) {
+    return NULL;
+  } else {
+    return publish_app_metadata(call, elem, 1);
+  }
 }
 
 grpc_call_stack *grpc_call_get_call_stack(grpc_call *call) {
   return CALL_STACK_FROM_CALL(call);
 }
 
-/*******************************************************************************
+/*
  * BATCH API IMPLEMENTATION
  */
 
@@ -984,83 +1053,14 @@ static void finish_batch_completion(grpc_exec_ctx *exec_ctx, void *user_data,
   GRPC_CALL_INTERNAL_UNREF(exec_ctx, call, "completion");
 }
 
-static grpc_error *consolidate_batch_errors(batch_control *bctl) {
-  size_t n = (size_t)gpr_atm_no_barrier_load(&bctl->num_errors);
-  if (n == 0) {
-    return GRPC_ERROR_NONE;
-  } else if (n == 1) {
-    return bctl->errors[0];
-  } else {
-    grpc_error *error =
-        GRPC_ERROR_CREATE_REFERENCING("Call batch failed", bctl->errors, n);
-    for (size_t i = 0; i < n; i++) {
-      GRPC_ERROR_UNREF(bctl->errors[i]);
-    }
-    return error;
-  }
-}
-
 static void post_batch_completion(grpc_exec_ctx *exec_ctx,
                                   batch_control *bctl) {
-  grpc_call *child_call;
-  grpc_call *next_child_call;
   grpc_call *call = bctl->call;
-  grpc_error *error = consolidate_batch_errors(bctl);
-
-  gpr_mu_lock(&call->mu);
-
-  if (error != GRPC_ERROR_NONE) {
-    set_status_from_error(exec_ctx, call, STATUS_FROM_CORE,
-                          GRPC_ERROR_REF(error));
-  }
-
-  if (bctl->send_initial_metadata) {
-    grpc_metadata_batch_destroy(
-        exec_ctx,
-        &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */]);
-  }
-  if (bctl->send_message) {
-    call->sending_message = false;
-  }
-  if (bctl->send_final_op) {
-    grpc_metadata_batch_destroy(
-        exec_ctx,
-        &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */]);
-  }
+  grpc_error *error = bctl->error;
   if (bctl->recv_final_op) {
-    grpc_metadata_batch *md =
-        &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
-    recv_trailing_filter(exec_ctx, call, md);
-
-    call->received_final_op = true;
-    /* propagate cancellation to any interested children */
-    child_call = call->first_child;
-    if (child_call != NULL) {
-      do {
-        next_child_call = child_call->sibling_next;
-        if (child_call->cancellation_is_inherited) {
-          GRPC_CALL_INTERNAL_REF(child_call, "propagate_cancel");
-          grpc_call_cancel(child_call, NULL);
-          GRPC_CALL_INTERNAL_UNREF(exec_ctx, child_call, "propagate_cancel");
-        }
-        child_call = next_child_call;
-      } while (child_call != call->first_child);
-    }
-
-    if (call->is_client) {
-      get_final_status(call, set_status_value_directly,
-                       call->final_op.client.status,
-                       call->final_op.client.status_details);
-    } else {
-      get_final_status(call, set_cancelled_value,
-                       call->final_op.server.cancelled, NULL);
-    }
-
     GRPC_ERROR_UNREF(error);
     error = GRPC_ERROR_NONE;
   }
-  gpr_mu_unlock(&call->mu);
-
   if (bctl->is_notify_tag_closure) {
     /* unrefs bctl->error */
     grpc_closure_run(exec_ctx, bctl->notify_tag, error);
@@ -1077,12 +1077,6 @@ static void post_batch_completion(grpc_exec_ctx *exec_ctx,
   }
 }
 
-static void finish_batch_step(grpc_exec_ctx *exec_ctx, batch_control *bctl) {
-  if (gpr_unref(&bctl->steps_to_complete)) {
-    post_batch_completion(exec_ctx, bctl);
-  }
-}
-
 static void continue_receiving_slices(grpc_exec_ctx *exec_ctx,
                                       batch_control *bctl) {
   grpc_call *call = bctl->call;
@@ -1093,7 +1087,9 @@ static void continue_receiving_slices(grpc_exec_ctx *exec_ctx,
       call->receiving_message = 0;
       grpc_byte_stream_destroy(exec_ctx, call->receiving_stream);
       call->receiving_stream = NULL;
-      finish_batch_step(exec_ctx, bctl);
+      if (gpr_unref(&bctl->steps_to_complete)) {
+        post_batch_completion(exec_ctx, bctl);
+      }
       return;
     }
     if (grpc_byte_stream_next(exec_ctx, call->receiving_stream,
@@ -1124,7 +1120,9 @@ static void receiving_slice_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
     call->receiving_stream = NULL;
     grpc_byte_buffer_destroy(*call->receiving_buffer);
     *call->receiving_buffer = NULL;
-    finish_batch_step(exec_ctx, bctl);
+    if (gpr_unref(&bctl->steps_to_complete)) {
+      post_batch_completion(exec_ctx, bctl);
+    }
   }
 }
 
@@ -1134,7 +1132,9 @@ static void process_data_after_md(grpc_exec_ctx *exec_ctx,
   if (call->receiving_stream == NULL) {
     *call->receiving_buffer = NULL;
     call->receiving_message = 0;
-    finish_batch_step(exec_ctx, bctl);
+    if (gpr_unref(&bctl->steps_to_complete)) {
+      post_batch_completion(exec_ctx, bctl);
+    }
   } else {
     call->test_only_last_message_flags = call->receiving_stream->flags;
     if ((call->receiving_stream->flags & GRPC_WRITE_INTERNAL_COMPRESS) &&
@@ -1154,11 +1154,14 @@ static void receiving_stream_ready(grpc_exec_ctx *exec_ctx, void *bctlp,
                                    grpc_error *error) {
   batch_control *bctl = bctlp;
   grpc_call *call = bctl->call;
-  gpr_mu_lock(&bctl->call->mu);
   if (error != GRPC_ERROR_NONE) {
-    cancel_with_error(exec_ctx, call, GRPC_ERROR_REF(error));
+    grpc_status_code status;
+    const char *msg;
+    grpc_error_get_status(error, &status, &msg);
+    close_with_status(exec_ctx, call, status, msg);
   }
-  if (call->has_initial_md_been_received || error != GRPC_ERROR_NONE ||
+  gpr_mu_lock(&bctl->call->mu);
+  if (bctl->call->has_initial_md_been_received || error != GRPC_ERROR_NONE ||
       call->receiving_stream == NULL) {
     gpr_mu_unlock(&bctl->call->mu);
     process_data_after_md(exec_ctx, bctlp);
@@ -1183,7 +1186,7 @@ static void validate_filtered_metadata(grpc_exec_ctx *exec_ctx,
       gpr_asprintf(&error_msg, "Invalid compression algorithm value '%d'.",
                    algo);
       gpr_log(GPR_ERROR, "%s", error_msg);
-      cancel_with_status(exec_ctx, call, GRPC_STATUS_UNIMPLEMENTED, error_msg);
+      close_with_status(exec_ctx, call, GRPC_STATUS_UNIMPLEMENTED, error_msg);
     } else if (grpc_compression_options_is_algorithm_enabled(
                    &compression_options, algo) == 0) {
       /* check if algorithm is supported by current channel config */
@@ -1192,7 +1195,7 @@ static void validate_filtered_metadata(grpc_exec_ctx *exec_ctx,
       gpr_asprintf(&error_msg, "Compression algorithm '%s' is disabled.",
                    algo_name);
       gpr_log(GPR_ERROR, "%s", error_msg);
-      cancel_with_status(exec_ctx, call, GRPC_STATUS_UNIMPLEMENTED, error_msg);
+      close_with_status(exec_ctx, call, GRPC_STATUS_UNIMPLEMENTED, error_msg);
     } else {
       call->incoming_compression_algorithm = algo;
     }
@@ -1218,12 +1221,12 @@ static void validate_filtered_metadata(grpc_exec_ctx *exec_ctx,
   }
 }
 
-static void add_batch_error(grpc_exec_ctx *exec_ctx, batch_control *bctl,
-                            grpc_error *error) {
+static void add_batch_error(batch_control *bctl, grpc_error *error) {
   if (error == GRPC_ERROR_NONE) return;
-  cancel_with_error(exec_ctx, bctl->call, GRPC_ERROR_REF(error));
-  int idx = (int)gpr_atm_no_barrier_fetch_add(&bctl->num_errors, 1);
-  bctl->errors[idx] = error;
+  if (bctl->error == GRPC_ERROR_NONE) {
+    bctl->error = GRPC_ERROR_CREATE("Call batch operation failed");
+  }
+  bctl->error = grpc_error_add_child(bctl->error, error);
 }
 
 static void receiving_initial_metadata_ready(grpc_exec_ctx *exec_ctx,
@@ -1233,13 +1236,12 @@ static void receiving_initial_metadata_ready(grpc_exec_ctx *exec_ctx,
 
   gpr_mu_lock(&call->mu);
 
-  add_batch_error(exec_ctx, bctl, GRPC_ERROR_REF(error));
+  add_batch_error(bctl, GRPC_ERROR_REF(error));
   if (error == GRPC_ERROR_NONE) {
     grpc_metadata_batch *md =
         &call->metadata_batch[1 /* is_receiving */][0 /* is_trailing */];
-    recv_initial_filter(exec_ctx, call, md);
+    grpc_metadata_batch_filter(exec_ctx, md, recv_initial_filter, call);
 
-    /* TODO(ctiller): this could be moved into recv_initial_filter now */
     GPR_TIMER_BEGIN("validate_filtered_metadata", 0);
     validate_filtered_metadata(exec_ctx, bctl);
     GPR_TIMER_END("validate_filtered_metadata", 0);
@@ -1263,15 +1265,85 @@ static void receiving_initial_metadata_ready(grpc_exec_ctx *exec_ctx,
 
   gpr_mu_unlock(&call->mu);
 
-  finish_batch_step(exec_ctx, bctl);
+  if (gpr_unref(&bctl->steps_to_complete)) {
+    post_batch_completion(exec_ctx, bctl);
+  }
 }
 
 static void finish_batch(grpc_exec_ctx *exec_ctx, void *bctlp,
                          grpc_error *error) {
   batch_control *bctl = bctlp;
+  grpc_call *call = bctl->call;
+  grpc_call *child_call;
+  grpc_call *next_child_call;
+
+  GRPC_ERROR_REF(error);
+
+  gpr_mu_lock(&call->mu);
+
+  // If the error has an associated status code, set the call's status.
+  intptr_t status;
+  if (error != GRPC_ERROR_NONE &&
+      grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, &status)) {
+    set_status_from_error(exec_ctx, call, STATUS_FROM_CORE, error);
+  }
+
+  if (bctl->send_initial_metadata) {
+    if (error != GRPC_ERROR_NONE) {
+      set_status_from_error(exec_ctx, call, STATUS_FROM_CORE, error);
+    }
+    grpc_metadata_batch_destroy(
+        exec_ctx,
+        &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */]);
+  }
+  if (bctl->send_message) {
+    call->sending_message = 0;
+  }
+  if (bctl->send_final_op) {
+    grpc_metadata_batch_destroy(
+        exec_ctx,
+        &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */]);
+  }
+  if (bctl->recv_final_op) {
+    grpc_metadata_batch *md =
+        &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
+    grpc_metadata_batch_filter(exec_ctx, md, recv_trailing_filter, call);
 
-  add_batch_error(exec_ctx, bctl, GRPC_ERROR_REF(error));
-  finish_batch_step(exec_ctx, bctl);
+    call->received_final_op = true;
+    /* propagate cancellation to any interested children */
+    child_call = call->first_child;
+    if (child_call != NULL) {
+      do {
+        next_child_call = child_call->sibling_next;
+        if (child_call->cancellation_is_inherited) {
+          GRPC_CALL_INTERNAL_REF(child_call, "propagate_cancel");
+          grpc_call_cancel(child_call, NULL);
+          GRPC_CALL_INTERNAL_UNREF(exec_ctx, child_call, "propagate_cancel");
+        }
+        child_call = next_child_call;
+      } while (child_call != call->first_child);
+    }
+
+    if (call->is_client) {
+      get_final_status(call, set_status_value_directly,
+                       call->final_op.client.status);
+      get_final_details(call, call->final_op.client.status_details,
+                        call->final_op.client.status_details_capacity);
+    } else {
+      get_final_status(call, set_cancelled_value,
+                       call->final_op.server.cancelled);
+    }
+
+    GRPC_ERROR_UNREF(error);
+    error = GRPC_ERROR_NONE;
+  }
+  add_batch_error(bctl, GRPC_ERROR_REF(error));
+  gpr_mu_unlock(&call->mu);
+  if (gpr_unref(&bctl->steps_to_complete)) {
+    post_batch_completion(exec_ctx, bctl);
+  }
+
+  GRPC_ERROR_UNREF(error);
 }
 
 static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
@@ -1305,6 +1377,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
 
   if (nops == 0) {
     GRPC_CALL_INTERNAL_REF(call, "completion");
+    bctl->error = GRPC_ERROR_NONE;
     if (!is_notify_tag_closure) {
       grpc_cq_begin_op(call->cq, notify_tag);
     }
@@ -1353,10 +1426,13 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
           const grpc_compression_algorithm calgo =
               compression_algorithm_for_level_locked(
                   call, effective_compression_level);
+          char *calgo_name = NULL;
+          grpc_compression_algorithm_name(calgo, &calgo_name);
           // the following will be picked up by the compress filter and used as
           // the call's compression algorithm.
-          compression_md.key = GRPC_MDSTR_GRPC_INTERNAL_ENCODING_REQUEST;
-          compression_md.value = grpc_compression_algorithm_slice(calgo);
+          compression_md.key = GRPC_COMPRESSION_REQUEST_ALGORITHM_MD_KEY;
+          compression_md.value = calgo_name;
+          compression_md.value_length = strlen(calgo_name);
           additional_metadata_count++;
         }
 
@@ -1385,7 +1461,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
           error = GRPC_CALL_ERROR_INVALID_FLAGS;
           goto done_with_error;
         }
-        if (op->data.send_message == NULL) {
+        if (op->data.send_message.send_message == NULL) {
           error = GRPC_CALL_ERROR_INVALID_MESSAGE;
           goto done_with_error;
         }
@@ -1397,11 +1473,13 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         call->sending_message = 1;
         grpc_slice_buffer_stream_init(
             &call->sending_stream,
-            &op->data.send_message->data.raw.slice_buffer, op->flags);
+            &op->data.send_message.send_message->data.raw.slice_buffer,
+            op->flags);
         /* If the outgoing buffer is already compressed, mark it as so in the
            flags. These will be picked up by the compression filter and further
            (wasteful) attempts at compression skipped. */
-        if (op->data.send_message->data.raw.compression > GRPC_COMPRESS_NONE) {
+        if (op->data.send_message.send_message->data.raw.compression >
+            GRPC_COMPRESS_NONE) {
           call->sending_stream.base.flags |= GRPC_WRITE_INTERNAL_COMPRESS;
         }
         stream_op->send_message = &call->sending_stream.base;
@@ -1449,25 +1527,19 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         call->send_extra_metadata_count = 1;
         call->send_extra_metadata[0].md = grpc_channel_get_reffed_status_elem(
             exec_ctx, call->channel, op->data.send_status_from_server.status);
-        {
-          grpc_error *override_error = GRPC_ERROR_NONE;
-          if (op->data.send_status_from_server.status != GRPC_STATUS_OK) {
-            override_error = GRPC_ERROR_CREATE("Error from server send status");
-          }
-          if (op->data.send_status_from_server.status_details != NULL) {
-            call->send_extra_metadata[1].md = grpc_mdelem_from_slices(
-                exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
-                grpc_slice_ref_internal(
-                    *op->data.send_status_from_server.status_details));
-            call->send_extra_metadata_count++;
-            char *msg = grpc_slice_to_c_string(
-                GRPC_MDVALUE(call->send_extra_metadata[1].md));
-            override_error = grpc_error_set_str(
-                override_error, GRPC_ERROR_STR_GRPC_MESSAGE, msg);
-            gpr_free(msg);
-          }
-          set_status_from_error(exec_ctx, call, STATUS_FROM_API_OVERRIDE,
-                                override_error);
+        if (op->data.send_status_from_server.status_details != NULL) {
+          call->send_extra_metadata[1].md = grpc_mdelem_from_metadata_strings(
+              exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
+              grpc_mdstr_from_string(
+                  op->data.send_status_from_server.status_details));
+          call->send_extra_metadata_count++;
+          set_status_details(
+              exec_ctx, call, STATUS_FROM_API_OVERRIDE,
+              GRPC_MDSTR_REF(call->send_extra_metadata[1].md->value));
+        }
+        if (op->data.send_status_from_server.status != GRPC_STATUS_OK) {
+          set_status_code(call, STATUS_FROM_API_OVERRIDE,
+                          (uint32_t)op->data.send_status_from_server.status);
         }
         if (!prepare_application_metadata(
                 exec_ctx, call,
@@ -1495,7 +1567,8 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
            that case we're not necessarily covered by a poller. */
         stream_op->covered_by_poller = call->is_client;
         call->received_initial_metadata = 1;
-        call->buffered_metadata[0] = op->data.recv_initial_metadata;
+        call->buffered_metadata[0] =
+            op->data.recv_initial_metadata.recv_initial_metadata;
         grpc_closure_init(&call->receiving_initial_metadata_ready,
                           receiving_initial_metadata_ready, bctl,
                           grpc_schedule_on_exec_ctx);
@@ -1518,7 +1591,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         }
         call->receiving_message = 1;
         bctl->recv_message = 1;
-        call->receiving_buffer = op->data.recv_message;
+        call->receiving_buffer = op->data.recv_message.recv_message;
         stream_op->recv_message = &call->receiving_stream;
         grpc_closure_init(&call->receiving_stream_ready, receiving_stream_ready,
                           bctl, grpc_schedule_on_exec_ctx);
@@ -1545,6 +1618,8 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         call->final_op.client.status = op->data.recv_status_on_client.status;
         call->final_op.client.status_details =
             op->data.recv_status_on_client.status_details;
+        call->final_op.client.status_details_capacity =
+            op->data.recv_status_on_client.status_details_capacity;
         bctl->recv_final_op = 1;
         stream_op->recv_trailing_metadata =
             &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
index 8c46a83d42..233340c329 100644
--- a/src/core/lib/surface/call.h
+++ b/src/core/lib/surface/call.h
@@ -61,7 +61,7 @@ typedef struct grpc_call_create_args {
 
   const void *server_transport_data;
 
-  grpc_mdelem *add_initial_metadata;
+  grpc_mdelem **add_initial_metadata;
   size_t add_initial_metadata_count;
 
   gpr_timespec send_deadline;
diff --git a/src/core/lib/surface/call_details.c b/src/core/lib/surface/call_details.c
index d0f88e1969..fe73da3f55 100644
--- a/src/core/lib/surface/call_details.c
+++ b/src/core/lib/surface/call_details.c
@@ -36,21 +36,15 @@
 
 #include <string.h>
 
-#include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/surface/api_trace.h"
 
 void grpc_call_details_init(grpc_call_details* cd) {
   GRPC_API_TRACE("grpc_call_details_init(cd=%p)", 1, (cd));
   memset(cd, 0, sizeof(*cd));
-  cd->method = grpc_empty_slice();
-  cd->host = grpc_empty_slice();
 }
 
 void grpc_call_details_destroy(grpc_call_details* cd) {
   GRPC_API_TRACE("grpc_call_details_destroy(cd=%p)", 1, (cd));
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_slice_unref_internal(&exec_ctx, cd->method);
-  grpc_slice_unref_internal(&exec_ctx, cd->host);
-  grpc_exec_ctx_finish(&exec_ctx);
+  gpr_free(cd->method);
+  gpr_free(cd->host);
 }
diff --git a/src/core/lib/surface/call_log_batch.c b/src/core/lib/surface/call_log_batch.c
index 7fc58e19c2..61b73a138f 100644
--- a/src/core/lib/surface/call_log_batch.c
+++ b/src/core/lib/surface/call_log_batch.c
@@ -35,22 +35,17 @@
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
 
 static void add_metadata(gpr_strvec *b, const grpc_metadata *md, size_t count) {
   size_t i;
-  if (md == NULL) {
-    gpr_strvec_add(b, gpr_strdup("(nil)"));
-    return;
-  }
   for (i = 0; i < count; i++) {
     gpr_strvec_add(b, gpr_strdup("\nkey="));
-    gpr_strvec_add(b, grpc_slice_to_c_string(md[i].key));
+    gpr_strvec_add(b, gpr_strdup(md[i].key));
 
     gpr_strvec_add(b, gpr_strdup(" value="));
-    gpr_strvec_add(b,
-                   grpc_dump_slice(md[i].value, GPR_DUMP_HEX | GPR_DUMP_ASCII));
+    gpr_strvec_add(b, gpr_dump(md[i].value, md[i].value_length,
+                               GPR_DUMP_HEX | GPR_DUMP_ASCII));
   }
 }
 
@@ -68,33 +63,29 @@ char *grpc_op_string(const grpc_op *op) {
                    op->data.send_initial_metadata.count);
       break;
     case GRPC_OP_SEND_MESSAGE:
-      gpr_asprintf(&tmp, "SEND_MESSAGE ptr=%p", op->data.send_message);
+      gpr_asprintf(&tmp, "SEND_MESSAGE ptr=%p",
+                   op->data.send_message.send_message);
       gpr_strvec_add(&b, tmp);
       break;
     case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
       gpr_strvec_add(&b, gpr_strdup("SEND_CLOSE_FROM_CLIENT"));
       break;
     case GRPC_OP_SEND_STATUS_FROM_SERVER:
-      gpr_asprintf(&tmp, "SEND_STATUS_FROM_SERVER status=%d details=",
-                   op->data.send_status_from_server.status);
+      gpr_asprintf(&tmp, "SEND_STATUS_FROM_SERVER status=%d details=%s",
+                   op->data.send_status_from_server.status,
+                   op->data.send_status_from_server.status_details);
       gpr_strvec_add(&b, tmp);
-      if (op->data.send_status_from_server.status_details != NULL) {
-        gpr_strvec_add(&b, grpc_dump_slice(
-                               *op->data.send_status_from_server.status_details,
-                               GPR_DUMP_ASCII));
-      } else {
-        gpr_strvec_add(&b, gpr_strdup("(null)"));
-      }
       add_metadata(&b, op->data.send_status_from_server.trailing_metadata,
                    op->data.send_status_from_server.trailing_metadata_count);
       break;
     case GRPC_OP_RECV_INITIAL_METADATA:
       gpr_asprintf(&tmp, "RECV_INITIAL_METADATA ptr=%p",
-                   op->data.recv_initial_metadata);
+                   op->data.recv_initial_metadata.recv_initial_metadata);
       gpr_strvec_add(&b, tmp);
       break;
     case GRPC_OP_RECV_MESSAGE:
-      gpr_asprintf(&tmp, "RECV_MESSAGE ptr=%p", op->data.recv_message);
+      gpr_asprintf(&tmp, "RECV_MESSAGE ptr=%p",
+                   op->data.recv_message.recv_message);
       gpr_strvec_add(&b, tmp);
       break;
     case GRPC_OP_RECV_STATUS_ON_CLIENT:
diff --git a/src/core/lib/surface/channel.c b/src/core/lib/surface/channel.c
index 429dbad7c7..b87295786e 100644
--- a/src/core/lib/surface/channel.c
+++ b/src/core/lib/surface/channel.c
@@ -43,7 +43,6 @@
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/iomgr/iomgr.h"
-#include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
@@ -58,15 +57,15 @@
 #define NUM_CACHED_STATUS_ELEMS 3
 
 typedef struct registered_call {
-  grpc_mdelem path;
-  grpc_mdelem authority;
+  grpc_mdelem *path;
+  grpc_mdelem *authority;
   struct registered_call *next;
 } registered_call;
 
 struct grpc_channel {
   int is_client;
   grpc_compression_options compression_options;
-  grpc_mdelem default_authority;
+  grpc_mdelem *default_authority;
 
   gpr_mu registered_call_mu;
   registered_call *registered_calls;
@@ -103,8 +102,9 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
       exec_ctx, builder, sizeof(grpc_channel), 1, destroy_channel, NULL,
       (void **)&channel);
   if (error != GRPC_ERROR_NONE) {
-    gpr_log(GPR_ERROR, "channel stack builder failed: %s",
-            grpc_error_string(error));
+    const char *msg = grpc_error_string(error);
+    gpr_log(GPR_ERROR, "channel stack builder failed: %s", msg);
+    grpc_error_free_string(msg);
     GRPC_ERROR_UNREF(error);
     goto done;
   }
@@ -116,19 +116,19 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
   channel->registered_calls = NULL;
 
   grpc_compression_options_init(&channel->compression_options);
+
   for (size_t i = 0; i < args->num_args; i++) {
     if (0 == strcmp(args->args[i].key, GRPC_ARG_DEFAULT_AUTHORITY)) {
       if (args->args[i].type != GRPC_ARG_STRING) {
         gpr_log(GPR_ERROR, "%s ignored: it must be a string",
                 GRPC_ARG_DEFAULT_AUTHORITY);
       } else {
-        if (!GRPC_MDISNULL(channel->default_authority)) {
+        if (channel->default_authority) {
           /* setting this takes precedence over anything else */
           GRPC_MDELEM_UNREF(exec_ctx, channel->default_authority);
         }
-        channel->default_authority = grpc_mdelem_from_slices(
-            exec_ctx, GRPC_MDSTR_AUTHORITY,
-            grpc_slice_from_copied_string(args->args[i].value.string));
+        channel->default_authority = grpc_mdelem_from_strings(
+            exec_ctx, ":authority", args->args[i].value.string);
       }
     } else if (0 ==
                strcmp(args->args[i].key, GRPC_SSL_TARGET_NAME_OVERRIDE_ARG)) {
@@ -136,15 +136,14 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
         gpr_log(GPR_ERROR, "%s ignored: it must be a string",
                 GRPC_SSL_TARGET_NAME_OVERRIDE_ARG);
       } else {
-        if (!GRPC_MDISNULL(channel->default_authority)) {
+        if (channel->default_authority) {
           /* other ways of setting this (notably ssl) take precedence */
           gpr_log(GPR_ERROR,
                   "%s ignored: default host already set some other way",
                   GRPC_SSL_TARGET_NAME_OVERRIDE_ARG);
         } else {
-          channel->default_authority = grpc_mdelem_from_slices(
-              exec_ctx, GRPC_MDSTR_AUTHORITY,
-              grpc_slice_from_copied_string(args->args[i].value.string));
+          channel->default_authority = grpc_mdelem_from_strings(
+              exec_ctx, ":authority", args->args[i].value.string);
         }
       }
     } else if (0 == strcmp(args->args[i].key,
@@ -192,18 +191,18 @@ void grpc_channel_get_info(grpc_channel *channel,
 static grpc_call *grpc_channel_create_call_internal(
     grpc_exec_ctx *exec_ctx, grpc_channel *channel, grpc_call *parent_call,
     uint32_t propagation_mask, grpc_completion_queue *cq,
-    grpc_pollset_set *pollset_set_alternative, grpc_mdelem path_mdelem,
-    grpc_mdelem authority_mdelem, gpr_timespec deadline) {
-  grpc_mdelem send_metadata[2];
+    grpc_pollset_set *pollset_set_alternative, grpc_mdelem *path_mdelem,
+    grpc_mdelem *authority_mdelem, gpr_timespec deadline) {
+  grpc_mdelem *send_metadata[2];
   size_t num_metadata = 0;
 
   GPR_ASSERT(channel->is_client);
   GPR_ASSERT(!(cq != NULL && pollset_set_alternative != NULL));
 
   send_metadata[num_metadata++] = path_mdelem;
-  if (!GRPC_MDISNULL(authority_mdelem)) {
+  if (authority_mdelem != NULL) {
     send_metadata[num_metadata++] = authority_mdelem;
-  } else if (!GRPC_MDISNULL(channel->default_authority)) {
+  } else if (channel->default_authority != NULL) {
     send_metadata[num_metadata++] = GRPC_MDELEM_REF(channel->default_authority);
   }
 
@@ -228,17 +227,27 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
                                     grpc_call *parent_call,
                                     uint32_t propagation_mask,
                                     grpc_completion_queue *cq,
-                                    grpc_slice method, const grpc_slice *host,
+                                    const char *method, const char *host,
                                     gpr_timespec deadline, void *reserved) {
+  GRPC_API_TRACE(
+      "grpc_channel_create_call("
+      "channel=%p, parent_call=%p, propagation_mask=%x, cq=%p, method=%s, "
+      "host=%s, "
+      "deadline=gpr_timespec { tv_sec: %" PRId64
+      ", tv_nsec: %d, clock_type: %d }, "
+      "reserved=%p)",
+      10,
+      (channel, parent_call, (unsigned)propagation_mask, cq, method, host,
+       deadline.tv_sec, deadline.tv_nsec, (int)deadline.clock_type, reserved));
   GPR_ASSERT(!reserved);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_call *call = grpc_channel_create_call_internal(
       &exec_ctx, channel, parent_call, propagation_mask, cq, NULL,
-      grpc_mdelem_from_slices(&exec_ctx, GRPC_MDSTR_PATH,
-                              grpc_slice_ref_internal(method)),
-      host != NULL ? grpc_mdelem_from_slices(&exec_ctx, GRPC_MDSTR_AUTHORITY,
-                                             grpc_slice_ref_internal(*host))
-                   : GRPC_MDNULL,
+      grpc_mdelem_from_metadata_strings(&exec_ctx, GRPC_MDSTR_PATH,
+                                        grpc_mdstr_from_string(method)),
+      host ? grpc_mdelem_from_metadata_strings(&exec_ctx, GRPC_MDSTR_AUTHORITY,
+                                               grpc_mdstr_from_string(host))
+           : NULL,
       deadline);
   grpc_exec_ctx_finish(&exec_ctx);
   return call;
@@ -246,16 +255,17 @@ grpc_call *grpc_channel_create_call(grpc_channel *channel,
 
 grpc_call *grpc_channel_create_pollset_set_call(
     grpc_exec_ctx *exec_ctx, grpc_channel *channel, grpc_call *parent_call,
-    uint32_t propagation_mask, grpc_pollset_set *pollset_set, grpc_slice method,
-    const grpc_slice *host, gpr_timespec deadline, void *reserved) {
+    uint32_t propagation_mask, grpc_pollset_set *pollset_set,
+    const char *method, const char *host, gpr_timespec deadline,
+    void *reserved) {
   GPR_ASSERT(!reserved);
   return grpc_channel_create_call_internal(
       exec_ctx, channel, parent_call, propagation_mask, NULL, pollset_set,
-      grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_PATH,
-                              grpc_slice_ref_internal(method)),
-      host != NULL ? grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_AUTHORITY,
-                                             grpc_slice_ref_internal(*host))
-                   : GRPC_MDNULL,
+      grpc_mdelem_from_metadata_strings(exec_ctx, GRPC_MDSTR_PATH,
+                                        grpc_mdstr_from_string(method)),
+      host ? grpc_mdelem_from_metadata_strings(exec_ctx, GRPC_MDSTR_AUTHORITY,
+                                               grpc_mdstr_from_string(host))
+           : NULL,
       deadline);
 }
 
@@ -267,15 +277,12 @@ void *grpc_channel_register_call(grpc_channel *channel, const char *method,
       4, (channel, method, host, reserved));
   GPR_ASSERT(!reserved);
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-
-  rc->path = grpc_mdelem_from_slices(
-      &exec_ctx, GRPC_MDSTR_PATH,
-      grpc_slice_intern(grpc_slice_from_static_string(method)));
+  rc->path = grpc_mdelem_from_metadata_strings(&exec_ctx, GRPC_MDSTR_PATH,
+                                               grpc_mdstr_from_string(method));
   rc->authority =
-      host ? grpc_mdelem_from_slices(
-                 &exec_ctx, GRPC_MDSTR_AUTHORITY,
-                 grpc_slice_intern(grpc_slice_from_static_string(host)))
-           : GRPC_MDNULL;
+      host ? grpc_mdelem_from_metadata_strings(&exec_ctx, GRPC_MDSTR_AUTHORITY,
+                                               grpc_mdstr_from_string(host))
+           : NULL;
   gpr_mu_lock(&channel->registered_call_mu);
   rc->next = channel->registered_calls;
   channel->registered_calls = rc;
@@ -303,7 +310,8 @@ grpc_call *grpc_channel_create_registered_call(
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_call *call = grpc_channel_create_call_internal(
       &exec_ctx, channel, parent_call, propagation_mask, completion_queue, NULL,
-      GRPC_MDELEM_REF(rc->path), GRPC_MDELEM_REF(rc->authority), deadline);
+      GRPC_MDELEM_REF(rc->path),
+      rc->authority ? GRPC_MDELEM_REF(rc->authority) : NULL, deadline);
   grpc_exec_ctx_finish(&exec_ctx);
   return call;
 }
@@ -332,10 +340,14 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, void *arg,
     registered_call *rc = channel->registered_calls;
     channel->registered_calls = rc->next;
     GRPC_MDELEM_UNREF(exec_ctx, rc->path);
-    GRPC_MDELEM_UNREF(exec_ctx, rc->authority);
+    if (rc->authority) {
+      GRPC_MDELEM_UNREF(exec_ctx, rc->authority);
+    }
     gpr_free(rc);
   }
-  GRPC_MDELEM_UNREF(exec_ctx, channel->default_authority);
+  if (channel->default_authority != NULL) {
+    GRPC_MDELEM_UNREF(exec_ctx, channel->default_authority);
+  }
   gpr_mu_destroy(&channel->registered_call_mu);
   gpr_free(channel->target);
   gpr_free(channel);
@@ -364,8 +376,8 @@ grpc_compression_options grpc_channel_compression_options(
   return channel->compression_options;
 }
 
-grpc_mdelem grpc_channel_get_reffed_status_elem(grpc_exec_ctx *exec_ctx,
-                                                grpc_channel *channel, int i) {
+grpc_mdelem *grpc_channel_get_reffed_status_elem(grpc_exec_ctx *exec_ctx,
+                                                 grpc_channel *channel, int i) {
   char tmp[GPR_LTOA_MIN_BUFSIZE];
   switch (i) {
     case 0:
@@ -376,6 +388,6 @@ grpc_mdelem grpc_channel_get_reffed_status_elem(grpc_exec_ctx *exec_ctx,
       return GRPC_MDELEM_GRPC_STATUS_2;
   }
   gpr_ltoa(i, tmp);
-  return grpc_mdelem_from_slices(exec_ctx, GRPC_MDSTR_GRPC_STATUS,
-                                 grpc_slice_from_copied_string(tmp));
+  return grpc_mdelem_from_metadata_strings(exec_ctx, GRPC_MDSTR_GRPC_STATUS,
+                                           grpc_mdstr_from_string(tmp));
 }
diff --git a/src/core/lib/surface/channel.h b/src/core/lib/surface/channel.h
index 3a441d7add..2ebadb7a15 100644
--- a/src/core/lib/surface/channel.h
+++ b/src/core/lib/surface/channel.h
@@ -52,8 +52,9 @@ grpc_channel *grpc_channel_create(grpc_exec_ctx *exec_ctx, const char *target,
     value of \a propagation_mask (see propagation_bits.h for possible values) */
 grpc_call *grpc_channel_create_pollset_set_call(
     grpc_exec_ctx *exec_ctx, grpc_channel *channel, grpc_call *parent_call,
-    uint32_t propagation_mask, grpc_pollset_set *pollset_set, grpc_slice method,
-    const grpc_slice *host, gpr_timespec deadline, void *reserved);
+    uint32_t propagation_mask, grpc_pollset_set *pollset_set,
+    const char *method, const char *host, gpr_timespec deadline,
+    void *reserved);
 
 /** Get a (borrowed) pointer to this channels underlying channel stack */
 grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel);
@@ -62,9 +63,9 @@ grpc_channel_stack *grpc_channel_get_channel_stack(grpc_channel *channel);
     status_code.
 
     The returned elem is owned by the caller. */
-grpc_mdelem grpc_channel_get_reffed_status_elem(grpc_exec_ctx *exec_ctx,
-                                                grpc_channel *channel,
-                                                int status_code);
+grpc_mdelem *grpc_channel_get_reffed_status_elem(grpc_exec_ctx *exec_ctx,
+                                                 grpc_channel *channel,
+                                                 int status_code);
 
 #ifdef GRPC_STREAM_REFCOUNT_DEBUG
 void grpc_channel_internal_ref(grpc_channel *channel, const char *reason);
diff --git a/src/core/lib/surface/completion_queue.c b/src/core/lib/surface/completion_queue.c
index 1830842d00..4613c9021e 100644
--- a/src/core/lib/surface/completion_queue.c
+++ b/src/core/lib/surface/completion_queue.c
@@ -253,6 +253,7 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
     if (grpc_trace_operation_failures && error != GRPC_ERROR_NONE) {
       gpr_log(GPR_ERROR, "Operation failed: tag=%p, error=%s", tag, errmsg);
     }
+    grpc_error_free_string(errmsg);
   }
 
   storage->tag = tag;
@@ -293,7 +294,7 @@ void grpc_cq_end_op(grpc_exec_ctx *exec_ctx, grpc_completion_queue *cc,
     if (kick_error != GRPC_ERROR_NONE) {
       const char *msg = grpc_error_string(kick_error);
       gpr_log(GPR_ERROR, "Kick failed: %s", msg);
-
+      grpc_error_free_string(msg);
       GRPC_ERROR_UNREF(kick_error);
     }
   } else {
@@ -402,8 +403,8 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
       .stolen_completion = NULL,
       .tag = NULL,
       .first_loop = true};
-  grpc_exec_ctx exec_ctx =
-      GRPC_EXEC_CTX_INITIALIZER(0, cq_is_next_finished, &is_finished_arg);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(
+      cq_is_next_finished, &is_finished_arg);
   for (;;) {
     if (is_finished_arg.stolen_completion != NULL) {
       gpr_mu_unlock(cc->mu);
@@ -460,7 +461,7 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
         gpr_mu_unlock(cc->mu);
         const char *msg = grpc_error_string(err);
         gpr_log(GPR_ERROR, "Completion queue next failed: %s", msg);
-
+        grpc_error_free_string(msg);
         GRPC_ERROR_UNREF(err);
         memset(&ret, 0, sizeof(ret));
         ret.type = GRPC_QUEUE_TIMEOUT;
@@ -571,8 +572,8 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
       .stolen_completion = NULL,
       .tag = tag,
       .first_loop = true};
-  grpc_exec_ctx exec_ctx =
-      GRPC_EXEC_CTX_INITIALIZER(0, cq_is_pluck_finished, &is_finished_arg);
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(
+      cq_is_pluck_finished, &is_finished_arg);
   for (;;) {
     if (is_finished_arg.stolen_completion != NULL) {
       gpr_mu_unlock(cc->mu);
@@ -646,7 +647,7 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
         gpr_mu_unlock(cc->mu);
         const char *msg = grpc_error_string(err);
         gpr_log(GPR_ERROR, "Completion queue next failed: %s", msg);
-
+        grpc_error_free_string(msg);
         GRPC_ERROR_UNREF(err);
         memset(&ret, 0, sizeof(ret));
         ret.type = GRPC_QUEUE_TIMEOUT;
diff --git a/src/core/lib/surface/init.c b/src/core/lib/surface/init.c
index cfa1882775..f61bf1582e 100644
--- a/src/core/lib/surface/init.c
+++ b/src/core/lib/surface/init.c
@@ -55,7 +55,6 @@
 #include "src/core/lib/iomgr/iomgr.h"
 #include "src/core/lib/iomgr/resource_quota.h"
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel_init.h"
@@ -179,7 +178,6 @@ void grpc_init(void) {
   gpr_mu_lock(&g_init_mu);
   if (++g_initializations == 1) {
     gpr_time_init();
-    grpc_slice_intern_init();
     grpc_mdctx_global_init();
     grpc_channel_init_init();
     grpc_register_tracer("api", &grpc_api_trace);
@@ -244,7 +242,6 @@ void grpc_shutdown(void) {
     }
     grpc_mdctx_global_shutdown(&exec_ctx);
     grpc_handshaker_factory_registry_shutdown(&exec_ctx);
-    grpc_slice_intern_shutdown();
   }
   gpr_mu_unlock(&g_init_mu);
   grpc_exec_ctx_finish(&exec_ctx);
diff --git a/src/core/lib/surface/lame_client.c b/src/core/lib/surface/lame_client.c
index 48de0e1d5b..ae1eac09a9 100644
--- a/src/core/lib/surface/lame_client.c
+++ b/src/core/lib/surface/lame_client.c
@@ -44,12 +44,10 @@
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/channel.h"
-#include "src/core/lib/transport/static_metadata.h"
 
 typedef struct {
   grpc_linked_mdelem status;
   grpc_linked_mdelem details;
-  gpr_atm filled_metadata;
 } call_data;
 
 typedef struct {
@@ -60,23 +58,17 @@ typedef struct {
 static void fill_metadata(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
                           grpc_metadata_batch *mdb) {
   call_data *calld = elem->call_data;
-  if (!gpr_atm_no_barrier_cas(&calld->filled_metadata, 0, 1)) {
-    return;
-  }
   channel_data *chand = elem->channel_data;
   char tmp[GPR_LTOA_MIN_BUFSIZE];
   gpr_ltoa(chand->error_code, tmp);
-  calld->status.md = grpc_mdelem_from_slices(
-      exec_ctx, GRPC_MDSTR_GRPC_STATUS, grpc_slice_from_copied_string(tmp));
-  calld->details.md = grpc_mdelem_from_slices(
-      exec_ctx, GRPC_MDSTR_GRPC_MESSAGE,
-      grpc_slice_from_copied_string(chand->error_message));
+  calld->status.md = grpc_mdelem_from_strings(exec_ctx, "grpc-status", tmp);
+  calld->details.md =
+      grpc_mdelem_from_strings(exec_ctx, "grpc-message", chand->error_message);
   calld->status.prev = calld->details.next = NULL;
   calld->status.next = &calld->details;
   calld->details.prev = &calld->status;
   mdb->list.head = &calld->status;
   mdb->list.tail = &calld->details;
-  mdb->list.count = 2;
   mdb->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
 }
 
@@ -123,8 +115,6 @@ static void lame_start_transport_op(grpc_exec_ctx *exec_ctx,
 static grpc_error *init_call_elem(grpc_exec_ctx *exec_ctx,
                                   grpc_call_element *elem,
                                   grpc_call_element_args *args) {
-  call_data *calld = elem->call_data;
-  gpr_atm_no_barrier_store(&calld->filled_metadata, 0);
   return GRPC_ERROR_NONE;
 }
 
diff --git a/src/core/lib/surface/server.c b/src/core/lib/surface/server.c
index 3782b49122..9e916465be 100644
--- a/src/core/lib/surface/server.c
+++ b/src/core/lib/surface/server.c
@@ -98,9 +98,8 @@ typedef struct requested_call {
 typedef struct channel_registered_method {
   registered_method *server_registered_method;
   uint32_t flags;
-  bool has_host;
-  grpc_slice method;
-  grpc_slice host;
+  grpc_mdstr *method;
+  grpc_mdstr *host;
 } channel_registered_method;
 
 struct channel_data {
@@ -145,10 +144,8 @@ struct call_data {
   /** the current state of a call - see call_state */
   call_state state;
 
-  bool path_set;
-  bool host_set;
-  grpc_slice path;
-  grpc_slice host;
+  grpc_mdstr *path;
+  grpc_mdstr *host;
   gpr_timespec deadline;
 
   grpc_completion_queue *cq_new;
@@ -280,20 +277,18 @@ static void shutdown_cleanup(grpc_exec_ctx *exec_ctx, void *arg,
 }
 
 static void send_shutdown(grpc_exec_ctx *exec_ctx, grpc_channel *channel,
-                          bool send_goaway, grpc_error *send_disconnect) {
+                          int send_goaway, grpc_error *send_disconnect) {
   struct shutdown_cleanup_args *sc = gpr_malloc(sizeof(*sc));
   grpc_closure_init(&sc->closure, shutdown_cleanup, sc,
                     grpc_schedule_on_exec_ctx);
   grpc_transport_op *op = grpc_make_transport_op(&sc->closure);
   grpc_channel_element *elem;
 
-  op->goaway_error =
-      send_goaway
-          ? grpc_error_set_int(GRPC_ERROR_CREATE("Server shutdown"),
-                               GRPC_ERROR_INT_GRPC_STATUS, GRPC_STATUS_OK)
-          : GRPC_ERROR_NONE;
+  op->send_goaway = send_goaway;
   op->set_accept_stream = true;
   sc->slice = grpc_slice_from_copied_string("Server shutdown");
+  op->goaway_message = &sc->slice;
+  op->goaway_status = GRPC_STATUS_OK;
   op->disconnect_with_error = send_disconnect;
 
   elem = grpc_channel_stack_element(grpc_channel_get_channel_stack(channel), 0);
@@ -453,6 +448,7 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, channel_data *chand,
   if (grpc_server_channel_trace && error != GRPC_ERROR_NONE) {
     const char *msg = grpc_error_string(error);
     gpr_log(GPR_INFO, "Disconnected client: %s", msg);
+    grpc_error_free_string(msg);
   }
   GRPC_ERROR_UNREF(error);
 
@@ -465,6 +461,17 @@ static void destroy_channel(grpc_exec_ctx *exec_ctx, channel_data *chand,
                        op);
 }
 
+static void cpstr(char **dest, size_t *capacity, grpc_mdstr *value) {
+  grpc_slice slice = value->slice;
+  size_t len = GRPC_SLICE_LENGTH(slice);
+
+  if (len + 1 > *capacity) {
+    *capacity = GPR_MAX(len + 1, *capacity * 2);
+    *dest = gpr_realloc(*dest, *capacity);
+  }
+  memcpy(*dest, grpc_mdstr_as_c_string(value), len + 1);
+}
+
 static void done_request_event(grpc_exec_ctx *exec_ctx, void *req,
                                grpc_cq_completion *c) {
   requested_call *rc = req;
@@ -493,10 +500,12 @@ static void publish_call(grpc_exec_ctx *exec_ctx, grpc_server *server,
   GPR_SWAP(grpc_metadata_array, *rc->initial_metadata, calld->initial_metadata);
   switch (rc->type) {
     case BATCH_CALL:
-      GPR_ASSERT(calld->host_set);
-      GPR_ASSERT(calld->path_set);
-      rc->data.batch.details->host = grpc_slice_ref_internal(calld->host);
-      rc->data.batch.details->method = grpc_slice_ref_internal(calld->path);
+      GPR_ASSERT(calld->host != NULL);
+      GPR_ASSERT(calld->path != NULL);
+      cpstr(&rc->data.batch.details->host,
+            &rc->data.batch.details->host_capacity, calld->host);
+      cpstr(&rc->data.batch.details->method,
+            &rc->data.batch.details->method_capacity, calld->path);
       rc->data.batch.details->deadline = calld->deadline;
       rc->data.batch.details->flags =
           (calld->recv_idempotent_request
@@ -600,7 +609,7 @@ static void finish_start_new_rpc(
       grpc_op op;
       memset(&op, 0, sizeof(op));
       op.op = GRPC_OP_RECV_MESSAGE;
-      op.data.recv_message = &calld->payload;
+      op.data.recv_message.recv_message = &calld->payload;
       grpc_closure_init(&calld->publish, publish_new_rpc, elem,
                         grpc_schedule_on_exec_ctx);
       grpc_call_start_batch_and_execute(exec_ctx, calld->call, &op, 1,
@@ -618,39 +627,35 @@ static void start_new_rpc(grpc_exec_ctx *exec_ctx, grpc_call_element *elem) {
   uint32_t hash;
   channel_registered_method *rm;
 
-  if (chand->registered_methods && calld->path_set && calld->host_set) {
+  if (chand->registered_methods && calld->path && calld->host) {
     /* TODO(ctiller): unify these two searches */
     /* check for an exact match with host */
-    hash = GRPC_MDSTR_KV_HASH(grpc_slice_hash(calld->host),
-                              grpc_slice_hash(calld->path));
+    hash = GRPC_MDSTR_KV_HASH(calld->host->hash, calld->path->hash);
     for (i = 0; i <= chand->registered_method_max_probes; i++) {
       rm = &chand->registered_methods[(hash + i) %
                                       chand->registered_method_slots];
       if (!rm) break;
-      if (!rm->has_host) continue;
-      if (!grpc_slice_eq(rm->host, calld->host)) continue;
-      if (!grpc_slice_eq(rm->method, calld->path)) continue;
+      if (rm->host != calld->host) continue;
+      if (rm->method != calld->path) continue;
       if ((rm->flags & GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST) &&
-          !calld->recv_idempotent_request) {
+          !calld->recv_idempotent_request)
         continue;
-      }
       finish_start_new_rpc(exec_ctx, server, elem,
                            &rm->server_registered_method->request_matcher,
                            rm->server_registered_method->payload_handling);
       return;
     }
     /* check for a wildcard method definition (no host set) */
-    hash = GRPC_MDSTR_KV_HASH(0, grpc_slice_hash(calld->path));
+    hash = GRPC_MDSTR_KV_HASH(0, calld->path->hash);
     for (i = 0; i <= chand->registered_method_max_probes; i++) {
       rm = &chand->registered_methods[(hash + i) %
                                       chand->registered_method_slots];
       if (!rm) break;
-      if (rm->has_host) continue;
-      if (!grpc_slice_eq(rm->method, calld->path)) continue;
+      if (rm->host != NULL) continue;
+      if (rm->method != calld->path) continue;
       if ((rm->flags & GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST) &&
-          !calld->recv_idempotent_request) {
+          !calld->recv_idempotent_request)
         continue;
-      }
       finish_start_new_rpc(exec_ctx, server, elem,
                            &rm->server_registered_method->request_matcher,
                            rm->server_registered_method->payload_handling);
@@ -739,40 +744,43 @@ static void maybe_finish_shutdown(grpc_exec_ctx *exec_ctx,
   }
 }
 
+static grpc_mdelem *server_filter(grpc_exec_ctx *exec_ctx, void *user_data,
+                                  grpc_mdelem *md) {
+  grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
+  if (md->key == GRPC_MDSTR_PATH) {
+    if (calld->path == NULL) {
+      calld->path = GRPC_MDSTR_REF(md->value);
+    }
+    return NULL;
+  } else if (md->key == GRPC_MDSTR_AUTHORITY) {
+    if (calld->host == NULL) {
+      calld->host = GRPC_MDSTR_REF(md->value);
+    }
+    return NULL;
+  }
+  return md;
+}
+
 static void server_on_recv_initial_metadata(grpc_exec_ctx *exec_ctx, void *ptr,
                                             grpc_error *error) {
   grpc_call_element *elem = ptr;
   call_data *calld = elem->call_data;
   gpr_timespec op_deadline;
 
-  if (error == GRPC_ERROR_NONE) {
-    GPR_ASSERT(calld->recv_initial_metadata->idx.named.path != NULL);
-    GPR_ASSERT(calld->recv_initial_metadata->idx.named.authority != NULL);
-    calld->path = grpc_slice_ref_internal(
-        GRPC_MDVALUE(calld->recv_initial_metadata->idx.named.path->md));
-    calld->host = grpc_slice_ref_internal(
-        GRPC_MDVALUE(calld->recv_initial_metadata->idx.named.authority->md));
-    calld->path_set = true;
-    calld->host_set = true;
-    grpc_metadata_batch_remove(exec_ctx, calld->recv_initial_metadata,
-                               calld->recv_initial_metadata->idx.named.path);
-    grpc_metadata_batch_remove(
-        exec_ctx, calld->recv_initial_metadata,
-        calld->recv_initial_metadata->idx.named.authority);
-  } else {
-    GRPC_ERROR_REF(error);
-  }
+  GRPC_ERROR_REF(error);
+  grpc_metadata_batch_filter(exec_ctx, calld->recv_initial_metadata,
+                             server_filter, elem);
   op_deadline = calld->recv_initial_metadata->deadline;
   if (0 != gpr_time_cmp(op_deadline, gpr_inf_future(op_deadline.clock_type))) {
     calld->deadline = op_deadline;
   }
-  if (calld->host_set && calld->path_set) {
+  if (calld->host && calld->path) {
     /* do nothing */
   } else {
-    grpc_error *src_error = error;
+    GRPC_ERROR_UNREF(error);
     error =
         GRPC_ERROR_CREATE_REFERENCING("Missing :authority or :path", &error, 1);
-    GRPC_ERROR_UNREF(src_error);
   }
 
   grpc_closure_run(exec_ctx, calld->on_done_recv_initial_metadata, error);
@@ -849,7 +857,8 @@ static void accept_stream(grpc_exec_ctx *exec_ctx, void *cd,
   grpc_op op;
   memset(&op, 0, sizeof(op));
   op.op = GRPC_OP_RECV_INITIAL_METADATA;
-  op.data.recv_initial_metadata = &calld->initial_metadata;
+  op.data.recv_initial_metadata.recv_initial_metadata =
+      &calld->initial_metadata;
   grpc_closure_init(&calld->got_initial_metadata, got_initial_metadata, elem,
                     grpc_schedule_on_exec_ctx);
   grpc_call_start_batch_and_execute(exec_ctx, call, &op, 1,
@@ -902,11 +911,11 @@ static void destroy_call_elem(grpc_exec_ctx *exec_ctx, grpc_call_element *elem,
 
   GPR_ASSERT(calld->state != PENDING);
 
-  if (calld->host_set) {
-    grpc_slice_unref_internal(exec_ctx, calld->host);
+  if (calld->host) {
+    GRPC_MDSTR_UNREF(exec_ctx, calld->host);
   }
-  if (calld->path_set) {
-    grpc_slice_unref_internal(exec_ctx, calld->path);
+  if (calld->path) {
+    GRPC_MDSTR_UNREF(exec_ctx, calld->path);
   }
   grpc_metadata_array_destroy(&calld->initial_metadata);
 
@@ -938,9 +947,11 @@ static void destroy_channel_elem(grpc_exec_ctx *exec_ctx,
   channel_data *chand = elem->channel_data;
   if (chand->registered_methods) {
     for (i = 0; i < chand->registered_method_slots; i++) {
-      grpc_slice_unref_internal(exec_ctx, chand->registered_methods[i].method);
-      if (chand->registered_methods[i].has_host) {
-        grpc_slice_unref_internal(exec_ctx, chand->registered_methods[i].host);
+      if (chand->registered_methods[i].method) {
+        GRPC_MDSTR_UNREF(exec_ctx, chand->registered_methods[i].method);
+      }
+      if (chand->registered_methods[i].host) {
+        GRPC_MDSTR_UNREF(exec_ctx, chand->registered_methods[i].host);
       }
     }
     gpr_free(chand->registered_methods);
@@ -1138,6 +1149,8 @@ void grpc_server_setup_transport(grpc_exec_ctx *exec_ctx, grpc_server *s,
   channel_registered_method *crm;
   grpc_channel *channel;
   channel_data *chand;
+  grpc_mdstr *host;
+  grpc_mdstr *method;
   uint32_t hash;
   size_t slots;
   uint32_t probes;
@@ -1176,18 +1189,9 @@ void grpc_server_setup_transport(grpc_exec_ctx *exec_ctx, grpc_server *s,
     chand->registered_methods = gpr_malloc(alloc);
     memset(chand->registered_methods, 0, alloc);
     for (rm = s->registered_methods; rm; rm = rm->next) {
-      grpc_slice host;
-      bool has_host;
-      grpc_slice method;
-      if (rm->host != NULL) {
-        host = grpc_slice_intern(grpc_slice_from_static_string(rm->host));
-        has_host = true;
-      } else {
-        has_host = false;
-      }
-      method = grpc_slice_intern(grpc_slice_from_static_string(rm->method));
-      hash = GRPC_MDSTR_KV_HASH(has_host ? grpc_slice_hash(host) : 0,
-                                grpc_slice_hash(method));
+      host = rm->host ? grpc_mdstr_from_string(rm->host) : NULL;
+      method = grpc_mdstr_from_string(rm->method);
+      hash = GRPC_MDSTR_KV_HASH(host ? host->hash : 0, method->hash);
       for (probes = 0; chand->registered_methods[(hash + probes) % slots]
                            .server_registered_method != NULL;
            probes++)
@@ -1196,7 +1200,6 @@ void grpc_server_setup_transport(grpc_exec_ctx *exec_ctx, grpc_server *s,
       crm = &chand->registered_methods[(hash + probes) % slots];
       crm->server_registered_method = rm;
       crm->flags = rm->flags;
-      crm->has_host = has_host;
       crm->host = host;
       crm->method = method;
     }
diff --git a/src/core/lib/surface/validate_metadata.c b/src/core/lib/surface/validate_metadata.c
index 7ec9137265..f49dd8584b 100644
--- a/src/core/lib/surface/validate_metadata.c
+++ b/src/core/lib/surface/validate_metadata.c
@@ -34,71 +34,40 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include <grpc/grpc.h>
-#include <grpc/support/alloc.h>
 #include <grpc/support/port_platform.h>
 
-#include "src/core/lib/iomgr/error.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
-
-static grpc_error *conforms_to(grpc_slice slice, const uint8_t *legal_bits,
-                               const char *err_desc) {
-  const uint8_t *p = GRPC_SLICE_START_PTR(slice);
-  const uint8_t *e = GRPC_SLICE_END_PTR(slice);
+static int conforms_to(const char *s, size_t len, const uint8_t *legal_bits) {
+  const char *p = s;
+  const char *e = s + len;
   for (; p != e; p++) {
-    int idx = *p;
+    int idx = (uint8_t)*p;
     int byte = idx / 8;
     int bit = idx % 8;
-    if ((legal_bits[byte] & (1 << bit)) == 0) {
-      char *dump = grpc_dump_slice(slice, GPR_DUMP_HEX | GPR_DUMP_ASCII);
-      grpc_error *error = grpc_error_set_str(
-          grpc_error_set_int(GRPC_ERROR_CREATE(err_desc), GRPC_ERROR_INT_OFFSET,
-                             p - GRPC_SLICE_START_PTR(slice)),
-          GRPC_ERROR_STR_RAW_BYTES, dump);
-      gpr_free(dump);
-      return error;
-    }
+    if ((legal_bits[byte] & (1 << bit)) == 0) return 0;
   }
-  return GRPC_ERROR_NONE;
-}
-
-static int error2int(grpc_error *error) {
-  int r = (error == GRPC_ERROR_NONE);
-  GRPC_ERROR_UNREF(error);
-  return r;
+  return 1;
 }
 
-grpc_error *grpc_validate_header_key_is_legal(grpc_slice slice) {
+int grpc_header_key_is_legal(const char *key, size_t length) {
   static const uint8_t legal_header_bits[256 / 8] = {
       0x00, 0x00, 0x00, 0x00, 0x00, 0x60, 0xff, 0x03, 0x00, 0x00, 0x00,
       0x80, 0xfe, 0xff, 0xff, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  if (GRPC_SLICE_LENGTH(slice) == 0) {
-    return GRPC_ERROR_CREATE("Metadata keys cannot be zero length");
-  }
-  if (GRPC_SLICE_START_PTR(slice)[0] == ':') {
-    return GRPC_ERROR_CREATE("Metadata keys cannot start with :");
+  if (length == 0 || key[0] == ':') {
+    return 0;
   }
-  return conforms_to(slice, legal_header_bits, "Illegal header key");
+  return conforms_to(key, length, legal_header_bits);
 }
 
-int grpc_header_key_is_legal(grpc_slice slice) {
-  return error2int(grpc_validate_header_key_is_legal(slice));
-}
-
-grpc_error *grpc_validate_header_nonbin_value_is_legal(grpc_slice slice) {
+int grpc_header_nonbin_value_is_legal(const char *value, size_t length) {
   static const uint8_t legal_header_bits[256 / 8] = {
       0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
       0xff, 0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-  return conforms_to(slice, legal_header_bits, "Illegal header value");
-}
-
-int grpc_header_nonbin_value_is_legal(grpc_slice slice) {
-  return error2int(grpc_validate_header_nonbin_value_is_legal(slice));
+  return conforms_to(value, length, legal_header_bits);
 }
 
-int grpc_is_binary_header(grpc_slice slice) {
-  if (GRPC_SLICE_LENGTH(slice) < 5) return 0;
-  return 0 == memcmp(GRPC_SLICE_END_PTR(slice) - 4, "-bin", 4);
+int grpc_is_binary_header(const char *key, size_t length) {
+  if (length < 5) return 0;
+  return 0 == memcmp(key + length - 4, "-bin", 4);
 }
diff --git a/src/core/lib/surface/validate_metadata.h b/src/core/lib/surface/validate_metadata.h
deleted file mode 100644
index 2b800d25a4..0000000000
--- a/src/core/lib/surface/validate_metadata.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- *
- * Copyright 2017, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_SURFACE_VALIDATE_METADATA_H
-#define GRPC_CORE_LIB_SURFACE_VALIDATE_METADATA_H
-
-#include <grpc/slice.h>
-#include "src/core/lib/iomgr/error.h"
-
-grpc_error *grpc_validate_header_key_is_legal(grpc_slice slice);
-grpc_error *grpc_validate_header_nonbin_value_is_legal(grpc_slice slice);
-
-#endif /* GRPC_CORE_LIB_SURFACE_VALIDATE_METADATA_H */
diff --git a/src/core/lib/transport/connectivity_state.c b/src/core/lib/transport/connectivity_state.c
index 8fc5bf3e9a..c656d93740 100644
--- a/src/core/lib/transport/connectivity_state.c
+++ b/src/core/lib/transport/connectivity_state.c
@@ -163,6 +163,7 @@ void grpc_connectivity_state_set(grpc_exec_ctx *exec_ctx,
     gpr_log(GPR_DEBUG, "SET: %p %s: %s --> %s [%s] error=%p %s", tracker,
             tracker->name, grpc_connectivity_state_name(tracker->current_state),
             grpc_connectivity_state_name(state), reason, error, error_string);
+    grpc_error_free_string(error_string);
   }
   switch (state) {
     case GRPC_CHANNEL_INIT:
diff --git a/src/core/lib/transport/error_utils.c b/src/core/lib/transport/error_utils.c
deleted file mode 100644
index da77828d9c..0000000000
--- a/src/core/lib/transport/error_utils.c
+++ /dev/null
@@ -1,124 +0,0 @@
-/*
- *
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include "src/core/lib/transport/error_utils.h"
-
-#include "src/core/lib/iomgr/error_internal.h"
-#include "src/core/lib/transport/status_conversion.h"
-
-static grpc_error *recursively_find_error_with_field(grpc_error *error,
-                                                     grpc_error_ints which) {
-  // If the error itself has a status code, return it.
-  if (grpc_error_get_int(error, which, NULL)) {
-    return error;
-  }
-  if (grpc_error_is_special(error)) return NULL;
-  // Otherwise, search through its children.
-  intptr_t key = 0;
-  while (true) {
-    grpc_error *child_error = gpr_avl_get(error->errs, (void *)key++);
-    if (child_error == NULL) break;
-    grpc_error *result = recursively_find_error_with_field(child_error, which);
-    if (result != NULL) return result;
-  }
-  return NULL;
-}
-
-void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
-                           grpc_status_code *code, const char **msg,
-                           grpc_http2_error_code *http_error) {
-  // Start with the parent error and recurse through the tree of children
-  // until we find the first one that has a status code.
-  grpc_error *found_error =
-      recursively_find_error_with_field(error, GRPC_ERROR_INT_GRPC_STATUS);
-  if (found_error == NULL) {
-    /// If no grpc-status exists, retry through the tree to find a http2 error
-    /// code
-    found_error =
-        recursively_find_error_with_field(error, GRPC_ERROR_INT_HTTP2_ERROR);
-  }
-
-  // If we found an error with a status code above, use that; otherwise,
-  // fall back to using the parent error.
-  if (found_error == NULL) found_error = error;
-
-  grpc_status_code status = GRPC_STATUS_UNKNOWN;
-  intptr_t integer;
-  if (grpc_error_get_int(found_error, GRPC_ERROR_INT_GRPC_STATUS, &integer)) {
-    status = (grpc_status_code)integer;
-  } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR,
-                                &integer)) {
-    status = grpc_http2_error_to_grpc_status((grpc_http2_error_code)integer,
-                                             deadline);
-  }
-  if (code != NULL) *code = status;
-
-  if (http_error != NULL) {
-    if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR, &integer)) {
-      *http_error = (grpc_http2_error_code)integer;
-    } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_GRPC_STATUS,
-                                  &integer)) {
-      *http_error = grpc_status_to_http2_error((grpc_status_code)integer);
-    } else {
-      *http_error = found_error == GRPC_ERROR_NONE ? GRPC_HTTP2_NO_ERROR
-                                                   : GRPC_HTTP2_INTERNAL_ERROR;
-    }
-  }
-
-  // If the error has a status message, use it.  Otherwise, fall back to
-  // the error description.
-  if (msg != NULL) {
-    *msg = grpc_error_get_str(found_error, GRPC_ERROR_STR_GRPC_MESSAGE);
-    if (*msg == NULL && error != GRPC_ERROR_NONE) {
-      *msg = grpc_error_get_str(found_error, GRPC_ERROR_STR_DESCRIPTION);
-      if (*msg == NULL) *msg = "unknown error";  // Just in case.
-    }
-  }
-
-  if (found_error == NULL) found_error = error;
-}
-
-bool grpc_error_has_clear_grpc_status(grpc_error *error) {
-  if (grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, NULL)) {
-    return true;
-  }
-  intptr_t key = 0;
-  while (true) {
-    grpc_error *child_error = gpr_avl_get(error->errs, (void *)key++);
-    if (child_error == NULL) break;
-    if (grpc_error_has_clear_grpc_status(child_error)) {
-      return true;
-    }
-  }
-  return false;
-}
diff --git a/src/core/lib/transport/error_utils.h b/src/core/lib/transport/error_utils.h
deleted file mode 100644
index 105338880a..0000000000
--- a/src/core/lib/transport/error_utils.h
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- *
- * Copyright 2016, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_TRANSPORT_ERROR_UTILS_H
-#define GRPC_CORE_LIB_TRANSPORT_ERROR_UTILS_H
-
-#include "src/core/lib/iomgr/error.h"
-#include "src/core/lib/transport/http2_errors.h"
-
-/// A utility function to get the status code and message to be returned
-/// to the application.  If not set in the top-level message, looks
-/// through child errors until it finds the first one with these attributes.
-/// All attributes are pulled from the same child error. If any of the
-/// attributes (code, msg, http_status) are unneeded, they can be passed as
-/// NULL.
-void grpc_error_get_status(grpc_error *error, gpr_timespec deadline,
-                           grpc_status_code *code, const char **msg,
-                           grpc_http2_error_code *http_status);
-
-/// A utility function to check whether there is a clear status code that
-/// doesn't need to be guessed in \a error. This means that \a error or some
-/// child has GRPC_ERROR_INT_GRPC_STATUS set, or that it is GRPC_ERROR_NONE or
-/// GRPC_ERROR_CANCELLED
-bool grpc_error_has_clear_grpc_status(grpc_error *error);
-
-#endif /* GRPC_CORE_LIB_TRANSPORT_ERROR_UTILS_H */
diff --git a/src/core/lib/transport/http2_errors.h b/src/core/lib/transport/http2_errors.h
deleted file mode 100644
index 330bc987f6..0000000000
--- a/src/core/lib/transport/http2_errors.h
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_TRANSPORT_HTTP2_ERRORS_H
-#define GRPC_CORE_LIB_TRANSPORT_HTTP2_ERRORS_H
-
-/* error codes for RST_STREAM from http2 draft 14 section 7 */
-typedef enum {
-  GRPC_HTTP2_NO_ERROR = 0x0,
-  GRPC_HTTP2_PROTOCOL_ERROR = 0x1,
-  GRPC_HTTP2_INTERNAL_ERROR = 0x2,
-  GRPC_HTTP2_FLOW_CONTROL_ERROR = 0x3,
-  GRPC_HTTP2_SETTINGS_TIMEOUT = 0x4,
-  GRPC_HTTP2_STREAM_CLOSED = 0x5,
-  GRPC_HTTP2_FRAME_SIZE_ERROR = 0x6,
-  GRPC_HTTP2_REFUSED_STREAM = 0x7,
-  GRPC_HTTP2_CANCEL = 0x8,
-  GRPC_HTTP2_COMPRESSION_ERROR = 0x9,
-  GRPC_HTTP2_CONNECT_ERROR = 0xa,
-  GRPC_HTTP2_ENHANCE_YOUR_CALM = 0xb,
-  GRPC_HTTP2_INADEQUATE_SECURITY = 0xc,
-  /* force use of a default clause */
-  GRPC_HTTP2__ERROR_DO_NOT_USE = -1
-} grpc_http2_error_code;
-
-#endif /* GRPC_CORE_LIB_TRANSPORT_HTTP2_ERRORS_H */
diff --git a/src/core/lib/slice/slice_hash_table.c b/src/core/lib/transport/mdstr_hash_table.c
index 46f807f4a5..2791bf653b 100644
--- a/src/core/lib/slice/slice_hash_table.c
+++ b/src/core/lib/transport/mdstr_hash_table.c
@@ -29,7 +29,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 
-#include "src/core/lib/slice/slice_hash_table.h"
+#include "src/core/lib/transport/mdstr_hash_table.h"
 
 #include <stdbool.h>
 #include <string.h>
@@ -37,79 +37,70 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
-#include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/transport/metadata.h"
 
-struct grpc_slice_hash_table {
+struct grpc_mdstr_hash_table {
   gpr_refcount refs;
   size_t size;
-  grpc_slice_hash_table_entry* entries;
+  grpc_mdstr_hash_table_entry* entries;
 };
 
-static bool is_empty(grpc_slice_hash_table_entry* entry) {
-  return entry->vtable == NULL;
-}
-
 // Helper function for insert and get operations that performs quadratic
 // probing (https://en.wikipedia.org/wiki/Quadratic_probing).
-static size_t grpc_slice_hash_table_find_index(
-    const grpc_slice_hash_table* table, const grpc_slice key, bool find_empty) {
-  size_t hash = grpc_slice_hash(key);
+static size_t grpc_mdstr_hash_table_find_index(
+    const grpc_mdstr_hash_table* table, const grpc_mdstr* key,
+    bool find_empty) {
   for (size_t i = 0; i < table->size; ++i) {
-    const size_t idx = (hash + i * i) % table->size;
-    if (is_empty(&table->entries[idx])) {
-      return find_empty ? idx : table->size;
-    }
-    if (grpc_slice_eq(table->entries[idx].key, key)) {
-      return idx;
-    }
+    const size_t idx = (key->hash + i * i) % table->size;
+    if (table->entries[idx].key == NULL) return find_empty ? idx : table->size;
+    if (table->entries[idx].key == key) return idx;
   }
   return table->size;  // Not found.
 }
 
-static void grpc_slice_hash_table_add(
-    grpc_slice_hash_table* table, grpc_slice key, void* value,
-    const grpc_slice_hash_table_vtable* vtable) {
+static void grpc_mdstr_hash_table_add(
+    grpc_mdstr_hash_table* table, grpc_mdstr* key, void* value,
+    const grpc_mdstr_hash_table_vtable* vtable) {
   GPR_ASSERT(value != NULL);
   const size_t idx =
-      grpc_slice_hash_table_find_index(table, key, true /* find_empty */);
+      grpc_mdstr_hash_table_find_index(table, key, true /* find_empty */);
   GPR_ASSERT(idx != table->size);  // Table should never be full.
-  grpc_slice_hash_table_entry* entry = &table->entries[idx];
-  entry->key = grpc_slice_ref_internal(key);
+  grpc_mdstr_hash_table_entry* entry = &table->entries[idx];
+  entry->key = GRPC_MDSTR_REF(key);
   entry->value = vtable->copy_value(value);
   entry->vtable = vtable;
 }
 
-grpc_slice_hash_table* grpc_slice_hash_table_create(
-    size_t num_entries, grpc_slice_hash_table_entry* entries) {
-  grpc_slice_hash_table* table = gpr_malloc(sizeof(*table));
+grpc_mdstr_hash_table* grpc_mdstr_hash_table_create(
+    size_t num_entries, grpc_mdstr_hash_table_entry* entries) {
+  grpc_mdstr_hash_table* table = gpr_malloc(sizeof(*table));
   memset(table, 0, sizeof(*table));
   gpr_ref_init(&table->refs, 1);
   // Quadratic probing gets best performance when the table is no more
   // than half full.
   table->size = num_entries * 2;
-  const size_t entry_size = sizeof(grpc_slice_hash_table_entry) * table->size;
+  const size_t entry_size = sizeof(grpc_mdstr_hash_table_entry) * table->size;
   table->entries = gpr_malloc(entry_size);
   memset(table->entries, 0, entry_size);
   for (size_t i = 0; i < num_entries; ++i) {
-    grpc_slice_hash_table_entry* entry = &entries[i];
-    grpc_slice_hash_table_add(table, entry->key, entry->value, entry->vtable);
+    grpc_mdstr_hash_table_entry* entry = &entries[i];
+    grpc_mdstr_hash_table_add(table, entry->key, entry->value, entry->vtable);
   }
   return table;
 }
 
-grpc_slice_hash_table* grpc_slice_hash_table_ref(grpc_slice_hash_table* table) {
+grpc_mdstr_hash_table* grpc_mdstr_hash_table_ref(grpc_mdstr_hash_table* table) {
   if (table != NULL) gpr_ref(&table->refs);
   return table;
 }
 
-void grpc_slice_hash_table_unref(grpc_exec_ctx* exec_ctx,
-                                 grpc_slice_hash_table* table) {
+void grpc_mdstr_hash_table_unref(grpc_exec_ctx* exec_ctx,
+                                 grpc_mdstr_hash_table* table) {
   if (table != NULL && gpr_unref(&table->refs)) {
     for (size_t i = 0; i < table->size; ++i) {
-      grpc_slice_hash_table_entry* entry = &table->entries[i];
-      if (!is_empty(entry)) {
-        grpc_slice_unref_internal(exec_ctx, entry->key);
+      grpc_mdstr_hash_table_entry* entry = &table->entries[i];
+      if (entry->key != NULL) {
+        GRPC_MDSTR_UNREF(exec_ctx, entry->key);
         entry->vtable->destroy_value(exec_ctx, entry->value);
       }
     }
@@ -118,10 +109,10 @@ void grpc_slice_hash_table_unref(grpc_exec_ctx* exec_ctx,
   }
 }
 
-void* grpc_slice_hash_table_get(const grpc_slice_hash_table* table,
-                                const grpc_slice key) {
+void* grpc_mdstr_hash_table_get(const grpc_mdstr_hash_table* table,
+                                const grpc_mdstr* key) {
   const size_t idx =
-      grpc_slice_hash_table_find_index(table, key, false /* find_empty */);
+      grpc_mdstr_hash_table_find_index(table, key, false /* find_empty */);
   if (idx == table->size) return NULL;  // Not found.
   return table->entries[idx].value;
 }
diff --git a/src/core/lib/slice/slice_hash_table.h b/src/core/lib/transport/mdstr_hash_table.h
index d0c27122d7..57f497ee27 100644
--- a/src/core/lib/slice/slice_hash_table.h
+++ b/src/core/lib/transport/mdstr_hash_table.h
@@ -29,8 +29,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef GRPC_CORE_LIB_SLICE_SLICE_HASH_TABLE_H
-#define GRPC_CORE_LIB_SLICE_SLICE_HASH_TABLE_H
+#ifndef GRPC_CORE_LIB_TRANSPORT_MDSTR_HASH_TABLE_H
+#define GRPC_CORE_LIB_TRANSPORT_MDSTR_HASH_TABLE_H
 
 #include "src/core/lib/transport/metadata.h"
 
@@ -40,38 +40,38 @@
  * (https://en.wikipedia.org/wiki/Open_addressing) with quadratic
  * probing (https://en.wikipedia.org/wiki/Quadratic_probing).
  *
- * The keys are \a grpc_slice objects.  The values are arbitrary pointers
+ * The keys are \a grpc_mdstr objects.  The values are arbitrary pointers
  * with a common vtable.
  *
  * Hash tables are intentionally immutable, to avoid the need for locking.
  */
 
-typedef struct grpc_slice_hash_table grpc_slice_hash_table;
+typedef struct grpc_mdstr_hash_table grpc_mdstr_hash_table;
 
-typedef struct grpc_slice_hash_table_vtable {
-  void (*destroy_value)(grpc_exec_ctx *exec_ctx, void *value);
-  void *(*copy_value)(void *value);
-} grpc_slice_hash_table_vtable;
+typedef struct grpc_mdstr_hash_table_vtable {
+  void (*destroy_value)(grpc_exec_ctx* exec_ctx, void* value);
+  void* (*copy_value)(void* value);
+} grpc_mdstr_hash_table_vtable;
 
-typedef struct grpc_slice_hash_table_entry {
-  grpc_slice key;
-  void *value; /* Must not be NULL. */
-  const grpc_slice_hash_table_vtable *vtable;
-} grpc_slice_hash_table_entry;
+typedef struct grpc_mdstr_hash_table_entry {
+  grpc_mdstr* key;
+  void* value; /* Must not be NULL. */
+  const grpc_mdstr_hash_table_vtable* vtable;
+} grpc_mdstr_hash_table_entry;
 
 /** Creates a new hash table of containing \a entries, which is an array
     of length \a num_entries.
     Creates its own copy of all keys and values from \a entries. */
-grpc_slice_hash_table *grpc_slice_hash_table_create(
-    size_t num_entries, grpc_slice_hash_table_entry *entries);
+grpc_mdstr_hash_table* grpc_mdstr_hash_table_create(
+    size_t num_entries, grpc_mdstr_hash_table_entry* entries);
 
-grpc_slice_hash_table *grpc_slice_hash_table_ref(grpc_slice_hash_table *table);
-void grpc_slice_hash_table_unref(grpc_exec_ctx *exec_ctx,
-                                 grpc_slice_hash_table *table);
+grpc_mdstr_hash_table* grpc_mdstr_hash_table_ref(grpc_mdstr_hash_table* table);
+void grpc_mdstr_hash_table_unref(grpc_exec_ctx* exec_ctx,
+                                 grpc_mdstr_hash_table* table);
 
 /** Returns the value from \a table associated with \a key.
     Returns NULL if \a key is not found. */
-void *grpc_slice_hash_table_get(const grpc_slice_hash_table *table,
-                                const grpc_slice key);
+void* grpc_mdstr_hash_table_get(const grpc_mdstr_hash_table* table,
+                                const grpc_mdstr* key);
 
-#endif /* GRPC_CORE_LIB_SLICE_SLICE_HASH_TABLE_H */
+#endif /* GRPC_CORE_LIB_TRANSPORT_MDSTR_HASH_TABLE_H */
diff --git a/src/core/lib/transport/metadata.c b/src/core/lib/transport/metadata.c
index 489c20cbc8..54c39df6a7 100644
--- a/src/core/lib/transport/metadata.c
+++ b/src/core/lib/transport/metadata.c
@@ -48,11 +48,12 @@
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/profiling/timers.h"
 #include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/murmur_hash.h"
 #include "src/core/lib/support/string.h"
 #include "src/core/lib/transport/static_metadata.h"
 
+grpc_slice (*grpc_chttp2_base64_encode_and_huffman_compress)(grpc_slice input);
+
 /* There are two kinds of mdelem and mdstr instances.
  * Static instances are declared in static_metadata.{h,c} and
  * are initialized by grpc_mdctx_global_init().
@@ -62,6 +63,9 @@
  * used to determine which kind of element a pointer refers to.
  */
 
+#define INITIAL_STRTAB_CAPACITY 4
+#define INITIAL_MDTAB_CAPACITY 4
+
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
 #define DEBUG_ARGS , const char *file, int line
 #define FWD_DEBUG_ARGS , file, line
@@ -72,44 +76,58 @@
 #define REF_MD_LOCKED(shard, s) ref_md_locked((shard), (s))
 #endif
 
-#define INITIAL_SHARD_CAPACITY 8
-#define LOG2_SHARD_COUNT 4
-#define SHARD_COUNT ((size_t)(1 << LOG2_SHARD_COUNT))
-
-#define TABLE_IDX(hash, capacity) (((hash) >> (LOG2_SHARD_COUNT)) % (capacity))
-#define SHARD_IDX(hash) ((hash) & ((1 << (LOG2_SHARD_COUNT)) - 1))
+#define TABLE_IDX(hash, log2_shards, capacity) \
+  (((hash) >> (log2_shards)) % (capacity))
+#define SHARD_IDX(hash, log2_shards) ((hash) & ((1 << (log2_shards)) - 1))
 
 typedef void (*destroy_user_data_func)(void *user_data);
 
-/* Shadow structure for grpc_mdelem_data for interned elements */
-typedef struct interned_metadata {
-  /* must be byte compatible with grpc_mdelem_data */
-  grpc_slice key;
-  grpc_slice value;
+#define SIZE_IN_DECODER_TABLE_NOT_SET -1
+/* Shadow structure for grpc_mdstr for non-static values */
+typedef struct internal_string {
+  /* must be byte compatible with grpc_mdstr */
+  grpc_slice slice;
+  uint32_t hash;
 
   /* private only data */
   gpr_atm refcnt;
 
-  gpr_mu mu_user_data;
-  gpr_atm destroy_user_data;
-  gpr_atm user_data;
+  uint8_t has_base64_and_huffman_encoded;
+  grpc_slice_refcount refcount;
+
+  grpc_slice base64_and_huffman;
 
-  struct interned_metadata *bucket_next;
-} interned_metadata;
+  gpr_atm size_in_decoder_table;
 
-/* Shadow structure for grpc_mdelem_data for allocated elements */
-typedef struct allocated_metadata {
-  /* must be byte compatible with grpc_mdelem_data */
-  grpc_slice key;
-  grpc_slice value;
+  struct internal_string *bucket_next;
+} internal_string;
+
+/* Shadow structure for grpc_mdelem for non-static elements */
+typedef struct internal_metadata {
+  /* must be byte compatible with grpc_mdelem */
+  internal_string *key;
+  internal_string *value;
 
   /* private only data */
   gpr_atm refcnt;
-} allocated_metadata;
+
+  gpr_mu mu_user_data;
+  gpr_atm destroy_user_data;
+  gpr_atm user_data;
+
+  struct internal_metadata *bucket_next;
+} internal_metadata;
+
+typedef struct strtab_shard {
+  gpr_mu mu;
+  internal_string **strs;
+  size_t count;
+  size_t capacity;
+} strtab_shard;
 
 typedef struct mdtab_shard {
   gpr_mu mu;
-  interned_metadata **elems;
+  internal_metadata **elems;
   size_t count;
   size_t capacity;
   /** Estimate of the number of unreferenced mdelems in the hash table.
@@ -118,26 +136,102 @@ typedef struct mdtab_shard {
   gpr_atm free_estimate;
 } mdtab_shard;
 
-static mdtab_shard g_shards[SHARD_COUNT];
+#define LOG2_STRTAB_SHARD_COUNT 5
+#define LOG2_MDTAB_SHARD_COUNT 4
+#define STRTAB_SHARD_COUNT ((size_t)(1 << LOG2_STRTAB_SHARD_COUNT))
+#define MDTAB_SHARD_COUNT ((size_t)(1 << LOG2_MDTAB_SHARD_COUNT))
+
+/* hash seed: decided at initialization time */
+static uint32_t g_hash_seed;
+static int g_forced_hash_seed = 0;
+
+/* linearly probed hash tables for static element lookup */
+static grpc_mdstr *g_static_strtab[GRPC_STATIC_MDSTR_COUNT * 2];
+static grpc_mdelem *g_static_mdtab[GRPC_STATIC_MDELEM_COUNT * 2];
+static size_t g_static_strtab_maxprobe;
+static size_t g_static_mdtab_maxprobe;
+
+static strtab_shard g_strtab_shard[STRTAB_SHARD_COUNT];
+static mdtab_shard g_mdtab_shard[MDTAB_SHARD_COUNT];
 
 static void gc_mdtab(grpc_exec_ctx *exec_ctx, mdtab_shard *shard);
 
+void grpc_test_only_set_metadata_hash_seed(uint32_t seed) {
+  g_hash_seed = seed;
+  g_forced_hash_seed = 1;
+}
+
 void grpc_mdctx_global_init(void) {
+  size_t i, j;
+  if (!g_forced_hash_seed) {
+    g_hash_seed = (uint32_t)gpr_now(GPR_CLOCK_REALTIME).tv_nsec;
+  }
+  g_static_strtab_maxprobe = 0;
+  g_static_mdtab_maxprobe = 0;
+  /* build static tables */
+  memset(g_static_mdtab, 0, sizeof(g_static_mdtab));
+  memset(g_static_strtab, 0, sizeof(g_static_strtab));
+  for (i = 0; i < GRPC_STATIC_MDSTR_COUNT; i++) {
+    grpc_mdstr *elem = &grpc_static_mdstr_table[i];
+    const char *str = grpc_static_metadata_strings[i];
+    uint32_t hash = gpr_murmur_hash3(str, strlen(str), g_hash_seed);
+    *(grpc_slice *)&elem->slice = grpc_slice_from_static_string(str);
+    *(uint32_t *)&elem->hash = hash;
+    for (j = 0;; j++) {
+      size_t idx = (hash + j) % GPR_ARRAY_SIZE(g_static_strtab);
+      if (g_static_strtab[idx] == NULL) {
+        g_static_strtab[idx] = &grpc_static_mdstr_table[i];
+        break;
+      }
+    }
+    if (j > g_static_strtab_maxprobe) {
+      g_static_strtab_maxprobe = j;
+    }
+  }
+  for (i = 0; i < GRPC_STATIC_MDELEM_COUNT; i++) {
+    grpc_mdelem *elem = &grpc_static_mdelem_table[i];
+    grpc_mdstr *key =
+        &grpc_static_mdstr_table[grpc_static_metadata_elem_indices[2 * i + 0]];
+    grpc_mdstr *value =
+        &grpc_static_mdstr_table[grpc_static_metadata_elem_indices[2 * i + 1]];
+    uint32_t hash = GRPC_MDSTR_KV_HASH(key->hash, value->hash);
+    *(grpc_mdstr **)&elem->key = key;
+    *(grpc_mdstr **)&elem->value = value;
+    for (j = 0;; j++) {
+      size_t idx = (hash + j) % GPR_ARRAY_SIZE(g_static_mdtab);
+      if (g_static_mdtab[idx] == NULL) {
+        g_static_mdtab[idx] = elem;
+        break;
+      }
+    }
+    if (j > g_static_mdtab_maxprobe) {
+      g_static_mdtab_maxprobe = j;
+    }
+  }
   /* initialize shards */
-  for (size_t i = 0; i < SHARD_COUNT; i++) {
-    mdtab_shard *shard = &g_shards[i];
+  for (i = 0; i < STRTAB_SHARD_COUNT; i++) {
+    strtab_shard *shard = &g_strtab_shard[i];
+    gpr_mu_init(&shard->mu);
+    shard->count = 0;
+    shard->capacity = INITIAL_STRTAB_CAPACITY;
+    shard->strs = gpr_malloc(sizeof(*shard->strs) * shard->capacity);
+    memset(shard->strs, 0, sizeof(*shard->strs) * shard->capacity);
+  }
+  for (i = 0; i < MDTAB_SHARD_COUNT; i++) {
+    mdtab_shard *shard = &g_mdtab_shard[i];
     gpr_mu_init(&shard->mu);
     shard->count = 0;
     gpr_atm_no_barrier_store(&shard->free_estimate, 0);
-    shard->capacity = INITIAL_SHARD_CAPACITY;
+    shard->capacity = INITIAL_MDTAB_CAPACITY;
     shard->elems = gpr_malloc(sizeof(*shard->elems) * shard->capacity);
     memset(shard->elems, 0, sizeof(*shard->elems) * shard->capacity);
   }
 }
 
 void grpc_mdctx_global_shutdown(grpc_exec_ctx *exec_ctx) {
-  for (size_t i = 0; i < SHARD_COUNT; i++) {
-    mdtab_shard *shard = &g_shards[i];
+  size_t i;
+  for (i = 0; i < MDTAB_SHARD_COUNT; i++) {
+    mdtab_shard *shard = &g_mdtab_shard[i];
     gpr_mu_destroy(&shard->mu);
     gc_mdtab(exec_ctx, shard);
     /* TODO(ctiller): GPR_ASSERT(shard->count == 0); */
@@ -150,35 +244,212 @@ void grpc_mdctx_global_shutdown(grpc_exec_ctx *exec_ctx) {
     }
     gpr_free(shard->elems);
   }
+  for (i = 0; i < STRTAB_SHARD_COUNT; i++) {
+    strtab_shard *shard = &g_strtab_shard[i];
+    gpr_mu_destroy(&shard->mu);
+    /* TODO(ctiller): GPR_ASSERT(shard->count == 0); */
+    if (shard->count != 0) {
+      gpr_log(GPR_DEBUG, "WARNING: %" PRIuPTR " metadata strings were leaked",
+              shard->count);
+      for (size_t j = 0; j < shard->capacity; j++) {
+        for (internal_string *s = shard->strs[j]; s; s = s->bucket_next) {
+          gpr_log(GPR_DEBUG, "LEAKED: %s",
+                  grpc_mdstr_as_c_string((grpc_mdstr *)s));
+        }
+      }
+      if (grpc_iomgr_abort_on_leaks()) {
+        abort();
+      }
+    }
+    gpr_free(shard->strs);
+  }
 }
 
-static int is_mdelem_static(grpc_mdelem e) {
-  return GRPC_MDELEM_DATA(e) >= &grpc_static_mdelem_table[0] &&
-         GRPC_MDELEM_DATA(e) <
-             &grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT];
+static int is_mdstr_static(grpc_mdstr *s) {
+  return s >= &grpc_static_mdstr_table[0] &&
+         s < &grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
+}
+
+static int is_mdelem_static(grpc_mdelem *e) {
+  return e >= &grpc_static_mdelem_table[0] &&
+         e < &grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT];
 }
 
 static void ref_md_locked(mdtab_shard *shard,
-                          interned_metadata *md DEBUG_ARGS) {
+                          internal_metadata *md DEBUG_ARGS) {
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
-  char *key_str = grpc_slice_to_c_string(md->key);
-  char *value_str = grpc_slice_to_c_string(md->value);
   gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
           "ELM   REF:%p:%zu->%zu: '%s' = '%s'", (void *)md,
           gpr_atm_no_barrier_load(&md->refcnt),
-          gpr_atm_no_barrier_load(&md->refcnt) + 1, key_str, value_str);
-  gpr_free(key_str);
-  gpr_free(value_str);
+          gpr_atm_no_barrier_load(&md->refcnt) + 1,
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->key),
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->value));
 #endif
   if (0 == gpr_atm_no_barrier_fetch_add(&md->refcnt, 1)) {
     gpr_atm_no_barrier_fetch_add(&shard->free_estimate, -1);
   }
 }
 
+static void grow_strtab(strtab_shard *shard) {
+  size_t capacity = shard->capacity * 2;
+  size_t i;
+  internal_string **strtab;
+  internal_string *s, *next;
+
+  GPR_TIMER_BEGIN("grow_strtab", 0);
+
+  strtab = gpr_malloc(sizeof(internal_string *) * capacity);
+  memset(strtab, 0, sizeof(internal_string *) * capacity);
+
+  for (i = 0; i < shard->capacity; i++) {
+    for (s = shard->strs[i]; s; s = next) {
+      size_t idx = TABLE_IDX(s->hash, LOG2_STRTAB_SHARD_COUNT, capacity);
+      next = s->bucket_next;
+      s->bucket_next = strtab[idx];
+      strtab[idx] = s;
+    }
+  }
+
+  gpr_free(shard->strs);
+  shard->strs = strtab;
+  shard->capacity = capacity;
+
+  GPR_TIMER_END("grow_strtab", 0);
+}
+
+static void internal_destroy_string(grpc_exec_ctx *exec_ctx,
+                                    strtab_shard *shard, internal_string *is) {
+  internal_string **prev_next;
+  internal_string *cur;
+  GPR_TIMER_BEGIN("internal_destroy_string", 0);
+  if (is->has_base64_and_huffman_encoded) {
+    grpc_slice_unref_internal(exec_ctx, is->base64_and_huffman);
+  }
+  for (prev_next = &shard->strs[TABLE_IDX(is->hash, LOG2_STRTAB_SHARD_COUNT,
+                                          shard->capacity)],
+      cur = *prev_next;
+       cur != is; prev_next = &cur->bucket_next, cur = cur->bucket_next)
+    ;
+  *prev_next = cur->bucket_next;
+  shard->count--;
+  gpr_free(is);
+  GPR_TIMER_END("internal_destroy_string", 0);
+}
+
+static void slice_ref(void *p) {
+  internal_string *is =
+      (internal_string *)((char *)p - offsetof(internal_string, refcount));
+  GRPC_MDSTR_REF((grpc_mdstr *)(is));
+}
+
+static void slice_unref(grpc_exec_ctx *exec_ctx, void *p) {
+  internal_string *is =
+      (internal_string *)((char *)p - offsetof(internal_string, refcount));
+  GRPC_MDSTR_UNREF(exec_ctx, (grpc_mdstr *)(is));
+}
+
+grpc_mdstr *grpc_mdstr_from_string(const char *str) {
+  return grpc_mdstr_from_buffer((const uint8_t *)str, strlen(str));
+}
+
+grpc_mdstr *grpc_mdstr_from_slice(grpc_exec_ctx *exec_ctx, grpc_slice slice) {
+  grpc_mdstr *result = grpc_mdstr_from_buffer(GRPC_SLICE_START_PTR(slice),
+                                              GRPC_SLICE_LENGTH(slice));
+  grpc_slice_unref_internal(exec_ctx, slice);
+  return result;
+}
+
+grpc_mdstr *grpc_mdstr_from_buffer(const uint8_t *buf, size_t length) {
+  uint32_t hash = gpr_murmur_hash3(buf, length, g_hash_seed);
+  internal_string *s;
+  strtab_shard *shard =
+      &g_strtab_shard[SHARD_IDX(hash, LOG2_STRTAB_SHARD_COUNT)];
+  size_t i;
+  size_t idx;
+
+  GPR_TIMER_BEGIN("grpc_mdstr_from_buffer", 0);
+
+  /* search for a static string */
+  for (i = 0; i <= g_static_strtab_maxprobe; i++) {
+    grpc_mdstr *ss;
+    idx = (hash + i) % GPR_ARRAY_SIZE(g_static_strtab);
+    ss = g_static_strtab[idx];
+    if (ss == NULL) break;
+    if (ss->hash == hash && GRPC_SLICE_LENGTH(ss->slice) == length &&
+        (length == 0 ||
+         0 == memcmp(buf, GRPC_SLICE_START_PTR(ss->slice), length))) {
+      GPR_TIMER_END("grpc_mdstr_from_buffer", 0);
+      return ss;
+    }
+  }
+
+  gpr_mu_lock(&shard->mu);
+
+  /* search for an existing string */
+  idx = TABLE_IDX(hash, LOG2_STRTAB_SHARD_COUNT, shard->capacity);
+  for (s = shard->strs[idx]; s; s = s->bucket_next) {
+    if (s->hash == hash && GRPC_SLICE_LENGTH(s->slice) == length &&
+        0 == memcmp(buf, GRPC_SLICE_START_PTR(s->slice), length)) {
+      if (gpr_atm_full_fetch_add(&s->refcnt, 1) == 0) {
+        /* If we get here, we've added a ref to something that was about to
+         * die - drop it immediately.
+         * The *only* possible path here (given the shard mutex) should be to
+         * drop from one ref back to zero - assert that with a CAS */
+        GPR_ASSERT(gpr_atm_rel_cas(&s->refcnt, 1, 0));
+        /* and treat this as if we were never here... sshhh */
+      } else {
+        gpr_mu_unlock(&shard->mu);
+        GPR_TIMER_END("grpc_mdstr_from_buffer", 0);
+        return (grpc_mdstr *)s;
+      }
+    }
+  }
+
+  /* not found: create a new string */
+  if (length + 1 < GRPC_SLICE_INLINED_SIZE) {
+    /* string data goes directly into the slice */
+    s = gpr_malloc(sizeof(internal_string));
+    gpr_atm_rel_store(&s->refcnt, 1);
+    s->slice.refcount = NULL;
+    memcpy(s->slice.data.inlined.bytes, buf, length);
+    s->slice.data.inlined.bytes[length] = 0;
+    s->slice.data.inlined.length = (uint8_t)length;
+  } else {
+    /* string data goes after the internal_string header, and we +1 for null
+       terminator */
+    s = gpr_malloc(sizeof(internal_string) + length + 1);
+    gpr_atm_rel_store(&s->refcnt, 1);
+    s->refcount.ref = slice_ref;
+    s->refcount.unref = slice_unref;
+    s->slice.refcount = &s->refcount;
+    s->slice.data.refcounted.bytes = (uint8_t *)(s + 1);
+    s->slice.data.refcounted.length = length;
+    memcpy(s->slice.data.refcounted.bytes, buf, length);
+    /* add a null terminator for cheap c string conversion when desired */
+    s->slice.data.refcounted.bytes[length] = 0;
+  }
+  s->has_base64_and_huffman_encoded = 0;
+  s->hash = hash;
+  s->size_in_decoder_table = SIZE_IN_DECODER_TABLE_NOT_SET;
+  s->bucket_next = shard->strs[idx];
+  shard->strs[idx] = s;
+
+  shard->count++;
+
+  if (shard->count > shard->capacity * 2) {
+    grow_strtab(shard);
+  }
+
+  gpr_mu_unlock(&shard->mu);
+  GPR_TIMER_END("grpc_mdstr_from_buffer", 0);
+
+  return (grpc_mdstr *)s;
+}
+
 static void gc_mdtab(grpc_exec_ctx *exec_ctx, mdtab_shard *shard) {
   size_t i;
-  interned_metadata **prev_next;
-  interned_metadata *md, *next;
+  internal_metadata **prev_next;
+  internal_metadata *md, *next;
   gpr_atm num_freed = 0;
 
   GPR_TIMER_BEGIN("gc_mdtab", 0);
@@ -188,8 +459,8 @@ static void gc_mdtab(grpc_exec_ctx *exec_ctx, mdtab_shard *shard) {
       void *user_data = (void *)gpr_atm_no_barrier_load(&md->user_data);
       next = md->bucket_next;
       if (gpr_atm_acq_load(&md->refcnt) == 0) {
-        grpc_slice_unref_internal(exec_ctx, md->key);
-        grpc_slice_unref_internal(exec_ctx, md->value);
+        GRPC_MDSTR_UNREF(exec_ctx, (grpc_mdstr *)md->key);
+        GRPC_MDSTR_UNREF(exec_ctx, (grpc_mdstr *)md->value);
         if (md->user_data) {
           ((destroy_user_data_func)gpr_atm_no_barrier_load(
               &md->destroy_user_data))(user_data);
@@ -210,22 +481,21 @@ static void gc_mdtab(grpc_exec_ctx *exec_ctx, mdtab_shard *shard) {
 static void grow_mdtab(mdtab_shard *shard) {
   size_t capacity = shard->capacity * 2;
   size_t i;
-  interned_metadata **mdtab;
-  interned_metadata *md, *next;
+  internal_metadata **mdtab;
+  internal_metadata *md, *next;
   uint32_t hash;
 
   GPR_TIMER_BEGIN("grow_mdtab", 0);
 
-  mdtab = gpr_malloc(sizeof(interned_metadata *) * capacity);
-  memset(mdtab, 0, sizeof(interned_metadata *) * capacity);
+  mdtab = gpr_malloc(sizeof(internal_metadata *) * capacity);
+  memset(mdtab, 0, sizeof(internal_metadata *) * capacity);
 
   for (i = 0; i < shard->capacity; i++) {
     for (md = shard->elems[i]; md; md = next) {
       size_t idx;
-      hash = GRPC_MDSTR_KV_HASH(grpc_slice_hash(md->key),
-                                grpc_slice_hash(md->value));
+      hash = GRPC_MDSTR_KV_HASH(md->key->hash, md->value->hash);
       next = md->bucket_next;
-      idx = TABLE_IDX(hash, capacity);
+      idx = TABLE_IDX(hash, LOG2_MDTAB_SHARD_COUNT, capacity);
       md->bucket_next = mdtab[idx];
       mdtab[idx] = md;
     }
@@ -247,77 +517,62 @@ static void rehash_mdtab(grpc_exec_ctx *exec_ctx, mdtab_shard *shard) {
   }
 }
 
-grpc_mdelem grpc_mdelem_create(
-    grpc_exec_ctx *exec_ctx, grpc_slice key, grpc_slice value,
-    grpc_mdelem_data *compatible_external_backing_store) {
-  if (!grpc_slice_is_interned(key) || !grpc_slice_is_interned(value)) {
-    if (compatible_external_backing_store != NULL) {
-      return GRPC_MAKE_MDELEM(compatible_external_backing_store,
-                              GRPC_MDELEM_STORAGE_EXTERNAL);
-    }
+grpc_mdelem *grpc_mdelem_from_metadata_strings(grpc_exec_ctx *exec_ctx,
+                                               grpc_mdstr *mkey,
+                                               grpc_mdstr *mvalue) {
+  internal_string *key = (internal_string *)mkey;
+  internal_string *value = (internal_string *)mvalue;
+  uint32_t hash = GRPC_MDSTR_KV_HASH(mkey->hash, mvalue->hash);
+  internal_metadata *md;
+  mdtab_shard *shard = &g_mdtab_shard[SHARD_IDX(hash, LOG2_MDTAB_SHARD_COUNT)];
+  size_t i;
+  size_t idx;
 
-    allocated_metadata *allocated = gpr_malloc(sizeof(*allocated));
-    allocated->key = grpc_slice_ref_internal(key);
-    allocated->value = grpc_slice_ref_internal(value);
-    gpr_atm_rel_store(&allocated->refcnt, 1);
-#ifdef GRPC_METADATA_REFCOUNT_DEBUG
-    char *key_str = grpc_slice_to_c_string(allocated->key);
-    char *value_str = grpc_slice_to_c_string(allocated->value);
-    gpr_log(GPR_DEBUG, "ELM ALLOC:%p:%zu: '%s' = '%s'", (void *)allocated,
-            gpr_atm_no_barrier_load(&allocated->refcnt), key_str, value_str);
-    gpr_free(key_str);
-    gpr_free(value_str);
-#endif
-    return GRPC_MAKE_MDELEM(allocated, GRPC_MDELEM_STORAGE_ALLOCATED);
-  }
+  GPR_TIMER_BEGIN("grpc_mdelem_from_metadata_strings", 0);
 
-  if (GRPC_IS_STATIC_METADATA_STRING(key) &&
-      GRPC_IS_STATIC_METADATA_STRING(value)) {
-    grpc_mdelem static_elem = grpc_static_mdelem_for_static_strings(
-        GRPC_STATIC_METADATA_INDEX(key), GRPC_STATIC_METADATA_INDEX(value));
-    if (!GRPC_MDISNULL(static_elem)) {
-      return static_elem;
+  if (is_mdstr_static(mkey) && is_mdstr_static(mvalue)) {
+    for (i = 0; i <= g_static_mdtab_maxprobe; i++) {
+      grpc_mdelem *smd;
+      idx = (hash + i) % GPR_ARRAY_SIZE(g_static_mdtab);
+      smd = g_static_mdtab[idx];
+      if (smd == NULL) break;
+      if (smd->key == mkey && smd->value == mvalue) {
+        GPR_TIMER_END("grpc_mdelem_from_metadata_strings", 0);
+        return smd;
+      }
     }
   }
 
-  uint32_t hash =
-      GRPC_MDSTR_KV_HASH(grpc_slice_hash(key), grpc_slice_hash(value));
-  interned_metadata *md;
-  mdtab_shard *shard = &g_shards[SHARD_IDX(hash)];
-  size_t idx;
-
-  GPR_TIMER_BEGIN("grpc_mdelem_from_metadata_strings", 0);
-
   gpr_mu_lock(&shard->mu);
 
-  idx = TABLE_IDX(hash, shard->capacity);
+  idx = TABLE_IDX(hash, LOG2_MDTAB_SHARD_COUNT, shard->capacity);
   /* search for an existing pair */
   for (md = shard->elems[idx]; md; md = md->bucket_next) {
-    if (grpc_slice_eq(key, md->key) && grpc_slice_eq(value, md->value)) {
+    if (md->key == key && md->value == value) {
       REF_MD_LOCKED(shard, md);
+      GRPC_MDSTR_UNREF(exec_ctx, (grpc_mdstr *)key);
+      GRPC_MDSTR_UNREF(exec_ctx, (grpc_mdstr *)value);
       gpr_mu_unlock(&shard->mu);
       GPR_TIMER_END("grpc_mdelem_from_metadata_strings", 0);
-      return GRPC_MAKE_MDELEM(md, GRPC_MDELEM_STORAGE_INTERNED);
+      return (grpc_mdelem *)md;
     }
   }
 
   /* not found: create a new pair */
-  md = gpr_malloc(sizeof(interned_metadata));
+  md = gpr_malloc(sizeof(internal_metadata));
   gpr_atm_rel_store(&md->refcnt, 1);
-  md->key = grpc_slice_ref_internal(key);
-  md->value = grpc_slice_ref_internal(value);
+  md->key = key;
+  md->value = value;
   md->user_data = 0;
   md->destroy_user_data = 0;
   md->bucket_next = shard->elems[idx];
   shard->elems[idx] = md;
   gpr_mu_init(&md->mu_user_data);
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
-  char *key_str = grpc_slice_to_c_string(md->key);
-  char *value_str = grpc_slice_to_c_string(md->value);
   gpr_log(GPR_DEBUG, "ELM   NEW:%p:%zu: '%s' = '%s'", (void *)md,
-          gpr_atm_no_barrier_load(&md->refcnt), key_str, value_str);
-  gpr_free(key_str);
-  gpr_free(value_str);
+          gpr_atm_no_barrier_load(&md->refcnt),
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->key),
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->value));
 #endif
   shard->count++;
 
@@ -329,26 +584,29 @@ grpc_mdelem grpc_mdelem_create(
 
   GPR_TIMER_END("grpc_mdelem_from_metadata_strings", 0);
 
-  return GRPC_MAKE_MDELEM(md, GRPC_MDELEM_STORAGE_INTERNED);
+  return (grpc_mdelem *)md;
+}
+
+grpc_mdelem *grpc_mdelem_from_strings(grpc_exec_ctx *exec_ctx, const char *key,
+                                      const char *value) {
+  return grpc_mdelem_from_metadata_strings(
+      exec_ctx, grpc_mdstr_from_string(key), grpc_mdstr_from_string(value));
 }
 
-grpc_mdelem grpc_mdelem_from_slices(grpc_exec_ctx *exec_ctx, grpc_slice key,
-                                    grpc_slice value) {
-  grpc_mdelem out = grpc_mdelem_create(exec_ctx, key, value, NULL);
-  grpc_slice_unref_internal(exec_ctx, key);
-  grpc_slice_unref_internal(exec_ctx, value);
-  return out;
+grpc_mdelem *grpc_mdelem_from_slices(grpc_exec_ctx *exec_ctx, grpc_slice key,
+                                     grpc_slice value) {
+  return grpc_mdelem_from_metadata_strings(
+      exec_ctx, grpc_mdstr_from_slice(exec_ctx, key),
+      grpc_mdstr_from_slice(exec_ctx, value));
 }
 
-grpc_mdelem grpc_mdelem_from_grpc_metadata(grpc_exec_ctx *exec_ctx,
-                                           grpc_metadata *metadata) {
-  bool changed = false;
-  grpc_slice key_slice =
-      grpc_slice_maybe_static_intern(metadata->key, &changed);
-  grpc_slice value_slice =
-      grpc_slice_maybe_static_intern(metadata->value, &changed);
-  return grpc_mdelem_create(exec_ctx, key_slice, value_slice,
-                            changed ? NULL : (grpc_mdelem_data *)metadata);
+grpc_mdelem *grpc_mdelem_from_string_and_buffer(grpc_exec_ctx *exec_ctx,
+                                                const char *key,
+                                                const uint8_t *value,
+                                                size_t value_length) {
+  return grpc_mdelem_from_metadata_strings(
+      exec_ctx, grpc_mdstr_from_string(key),
+      grpc_mdstr_from_buffer(value, value_length));
 }
 
 static size_t get_base64_encoded_size(size_t raw_length) {
@@ -356,176 +614,160 @@ static size_t get_base64_encoded_size(size_t raw_length) {
   return raw_length / 3 * 4 + tail_xtra[raw_length % 3];
 }
 
-size_t grpc_mdelem_get_size_in_hpack_table(grpc_mdelem elem) {
-  size_t overhead_and_key = 32 + GRPC_SLICE_LENGTH(GRPC_MDKEY(elem));
-  size_t value_len = GRPC_SLICE_LENGTH(GRPC_MDVALUE(elem));
-  if (grpc_is_binary_header(GRPC_MDKEY(elem))) {
-    return overhead_and_key + get_base64_encoded_size(value_len);
+size_t grpc_mdelem_get_size_in_hpack_table(grpc_mdelem *elem) {
+  size_t overhead_and_key = 32 + GRPC_SLICE_LENGTH(elem->key->slice);
+  size_t value_len = GRPC_SLICE_LENGTH(elem->value->slice);
+  if (is_mdstr_static(elem->value)) {
+    if (grpc_is_binary_header(
+            (const char *)GRPC_SLICE_START_PTR(elem->key->slice),
+            GRPC_SLICE_LENGTH(elem->key->slice))) {
+      return overhead_and_key + get_base64_encoded_size(value_len);
+    } else {
+      return overhead_and_key + value_len;
+    }
   } else {
-    return overhead_and_key + value_len;
+    internal_string *is = (internal_string *)elem->value;
+    gpr_atm current_size = gpr_atm_acq_load(&is->size_in_decoder_table);
+    if (current_size == SIZE_IN_DECODER_TABLE_NOT_SET) {
+      if (grpc_is_binary_header(
+              (const char *)GRPC_SLICE_START_PTR(elem->key->slice),
+              GRPC_SLICE_LENGTH(elem->key->slice))) {
+        current_size = (gpr_atm)get_base64_encoded_size(value_len);
+      } else {
+        current_size = (gpr_atm)value_len;
+      }
+      gpr_atm_rel_store(&is->size_in_decoder_table, current_size);
+    }
+    return overhead_and_key + (size_t)current_size;
   }
 }
 
-grpc_mdelem grpc_mdelem_ref(grpc_mdelem gmd DEBUG_ARGS) {
-  switch (GRPC_MDELEM_STORAGE(gmd)) {
-    case GRPC_MDELEM_STORAGE_EXTERNAL:
-    case GRPC_MDELEM_STORAGE_STATIC:
-      break;
-    case GRPC_MDELEM_STORAGE_INTERNED: {
-      interned_metadata *md = (interned_metadata *)GRPC_MDELEM_DATA(gmd);
+grpc_mdelem *grpc_mdelem_ref(grpc_mdelem *gmd DEBUG_ARGS) {
+  internal_metadata *md = (internal_metadata *)gmd;
+  if (is_mdelem_static(gmd)) return gmd;
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
-      char *key_str = grpc_slice_to_c_string(md->key);
-      char *value_str = grpc_slice_to_c_string(md->value);
-      gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
-              "ELM   REF:%p:%zu->%zu: '%s' = '%s'", (void *)md,
-              gpr_atm_no_barrier_load(&md->refcnt),
-              gpr_atm_no_barrier_load(&md->refcnt) + 1, key_str, value_str);
-      gpr_free(key_str);
-      gpr_free(value_str);
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+          "ELM   REF:%p:%zu->%zu: '%s' = '%s'", (void *)md,
+          gpr_atm_no_barrier_load(&md->refcnt),
+          gpr_atm_no_barrier_load(&md->refcnt) + 1,
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->key),
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->value));
 #endif
-      /* we can assume the ref count is >= 1 as the application is calling
-         this function - meaning that no adjustment to mdtab_free is necessary,
-         simplifying the logic here to be just an atomic increment */
-      /* use C assert to have this removed in opt builds */
-      GPR_ASSERT(gpr_atm_no_barrier_load(&md->refcnt) >= 1);
-      gpr_atm_no_barrier_fetch_add(&md->refcnt, 1);
-      break;
-    }
-    case GRPC_MDELEM_STORAGE_ALLOCATED: {
-      allocated_metadata *md = (allocated_metadata *)GRPC_MDELEM_DATA(gmd);
+  /* we can assume the ref count is >= 1 as the application is calling
+     this function - meaning that no adjustment to mdtab_free is necessary,
+     simplifying the logic here to be just an atomic increment */
+  /* use C assert to have this removed in opt builds */
+  GPR_ASSERT(gpr_atm_no_barrier_load(&md->refcnt) >= 1);
+  gpr_atm_no_barrier_fetch_add(&md->refcnt, 1);
+  return gmd;
+}
+
+void grpc_mdelem_unref(grpc_exec_ctx *exec_ctx, grpc_mdelem *gmd DEBUG_ARGS) {
+  internal_metadata *md = (internal_metadata *)gmd;
+  if (!md) return;
+  if (is_mdelem_static(gmd)) return;
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
-      char *key_str = grpc_slice_to_c_string(md->key);
-      char *value_str = grpc_slice_to_c_string(md->value);
-      gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
-              "ELM   REF:%p:%zu->%zu: '%s' = '%s'", (void *)md,
-              gpr_atm_no_barrier_load(&md->refcnt),
-              gpr_atm_no_barrier_load(&md->refcnt) + 1, key_str, value_str);
-      gpr_free(key_str);
-      gpr_free(value_str);
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
+          "ELM UNREF:%p:%zu->%zu: '%s' = '%s'", (void *)md,
+          gpr_atm_no_barrier_load(&md->refcnt),
+          gpr_atm_no_barrier_load(&md->refcnt) - 1,
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->key),
+          grpc_mdstr_as_c_string((grpc_mdstr *)md->value));
 #endif
-      /* we can assume the ref count is >= 1 as the application is calling
-         this function - meaning that no adjustment to mdtab_free is necessary,
-         simplifying the logic here to be just an atomic increment */
-      /* use C assert to have this removed in opt builds */
-      gpr_atm_no_barrier_fetch_add(&md->refcnt, 1);
-      break;
-    }
+  uint32_t hash = GRPC_MDSTR_KV_HASH(md->key->hash, md->value->hash);
+  const gpr_atm prev_refcount = gpr_atm_full_fetch_add(&md->refcnt, -1);
+  GPR_ASSERT(prev_refcount >= 1);
+  if (1 == prev_refcount) {
+    /* once the refcount hits zero, some other thread can come along and
+       free md at any time: it's unsafe from this point on to access it */
+    mdtab_shard *shard =
+        &g_mdtab_shard[SHARD_IDX(hash, LOG2_MDTAB_SHARD_COUNT)];
+    gpr_atm_no_barrier_fetch_add(&shard->free_estimate, 1);
   }
-  return gmd;
 }
 
-void grpc_mdelem_unref(grpc_exec_ctx *exec_ctx, grpc_mdelem gmd DEBUG_ARGS) {
-  switch (GRPC_MDELEM_STORAGE(gmd)) {
-    case GRPC_MDELEM_STORAGE_EXTERNAL:
-    case GRPC_MDELEM_STORAGE_STATIC:
-      break;
-    case GRPC_MDELEM_STORAGE_INTERNED: {
-      interned_metadata *md = (interned_metadata *)GRPC_MDELEM_DATA(gmd);
+const char *grpc_mdstr_as_c_string(const grpc_mdstr *s) {
+  return (const char *)GRPC_SLICE_START_PTR(s->slice);
+}
+
+size_t grpc_mdstr_length(const grpc_mdstr *s) { return GRPC_MDSTR_LENGTH(s); }
+
+grpc_mdstr *grpc_mdstr_ref(grpc_mdstr *gs DEBUG_ARGS) {
+  internal_string *s = (internal_string *)gs;
+  if (is_mdstr_static(gs)) return gs;
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
-      char *key_str = grpc_slice_to_c_string(md->key);
-      char *value_str = grpc_slice_to_c_string(md->value);
-      gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
-              "ELM UNREF:%p:%zu->%zu: '%s' = '%s'", (void *)md,
-              gpr_atm_no_barrier_load(&md->refcnt),
-              gpr_atm_no_barrier_load(&md->refcnt) - 1, key_str, value_str);
-      gpr_free(key_str);
-      gpr_free(value_str);
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "STR   REF:%p:%zu->%zu: '%s'",
+          (void *)s, gpr_atm_no_barrier_load(&s->refcnt),
+          gpr_atm_no_barrier_load(&s->refcnt) + 1, grpc_mdstr_as_c_string(gs));
 #endif
-      uint32_t hash = GRPC_MDSTR_KV_HASH(grpc_slice_hash(md->key),
-                                         grpc_slice_hash(md->value));
-      const gpr_atm prev_refcount = gpr_atm_full_fetch_add(&md->refcnt, -1);
-      GPR_ASSERT(prev_refcount >= 1);
-      if (1 == prev_refcount) {
-        /* once the refcount hits zero, some other thread can come along and
-           free md at any time: it's unsafe from this point on to access it */
-        mdtab_shard *shard = &g_shards[SHARD_IDX(hash)];
-        gpr_atm_no_barrier_fetch_add(&shard->free_estimate, 1);
-      }
-      break;
-    }
-    case GRPC_MDELEM_STORAGE_ALLOCATED: {
-      allocated_metadata *md = (allocated_metadata *)GRPC_MDELEM_DATA(gmd);
+  GPR_ASSERT(gpr_atm_full_fetch_add(&s->refcnt, 1) > 0);
+  return gs;
+}
+
+void grpc_mdstr_unref(grpc_exec_ctx *exec_ctx, grpc_mdstr *gs DEBUG_ARGS) {
+  internal_string *s = (internal_string *)gs;
+  if (is_mdstr_static(gs)) return;
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
-      char *key_str = grpc_slice_to_c_string(md->key);
-      char *value_str = grpc_slice_to_c_string(md->value);
-      gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG,
-              "ELM UNREF:%p:%zu->%zu: '%s' = '%s'", (void *)md,
-              gpr_atm_no_barrier_load(&md->refcnt),
-              gpr_atm_no_barrier_load(&md->refcnt) - 1, key_str, value_str);
-      gpr_free(key_str);
-      gpr_free(value_str);
+  gpr_log(file, line, GPR_LOG_SEVERITY_DEBUG, "STR UNREF:%p:%zu->%zu: '%s'",
+          (void *)s, gpr_atm_no_barrier_load(&s->refcnt),
+          gpr_atm_no_barrier_load(&s->refcnt) - 1, grpc_mdstr_as_c_string(gs));
 #endif
-      const gpr_atm prev_refcount = gpr_atm_full_fetch_add(&md->refcnt, -1);
-      GPR_ASSERT(prev_refcount >= 1);
-      if (1 == prev_refcount) {
-        grpc_slice_unref_internal(exec_ctx, md->key);
-        grpc_slice_unref_internal(exec_ctx, md->value);
-        gpr_free(md);
-      }
-      break;
-    }
+  if (1 == gpr_atm_full_fetch_add(&s->refcnt, -1)) {
+    strtab_shard *shard =
+        &g_strtab_shard[SHARD_IDX(s->hash, LOG2_STRTAB_SHARD_COUNT)];
+    gpr_mu_lock(&shard->mu);
+    GPR_ASSERT(0 == gpr_atm_no_barrier_load(&s->refcnt));
+    internal_destroy_string(exec_ctx, shard, s);
+    gpr_mu_unlock(&shard->mu);
   }
 }
 
-void *grpc_mdelem_get_user_data(grpc_mdelem md, void (*destroy_func)(void *)) {
-  switch (GRPC_MDELEM_STORAGE(md)) {
-    case GRPC_MDELEM_STORAGE_EXTERNAL:
-    case GRPC_MDELEM_STORAGE_ALLOCATED:
-      return NULL;
-    case GRPC_MDELEM_STORAGE_STATIC:
-      return (void *)grpc_static_mdelem_user_data[GRPC_MDELEM_DATA(md) -
-                                                  grpc_static_mdelem_table];
-    case GRPC_MDELEM_STORAGE_INTERNED: {
-      interned_metadata *im = (interned_metadata *)GRPC_MDELEM_DATA(md);
-      void *result;
-      if (gpr_atm_acq_load(&im->destroy_user_data) == (gpr_atm)destroy_func) {
-        return (void *)gpr_atm_no_barrier_load(&im->user_data);
-      } else {
-        return NULL;
-      }
-      return result;
-    }
+void *grpc_mdelem_get_user_data(grpc_mdelem *md, void (*destroy_func)(void *)) {
+  internal_metadata *im = (internal_metadata *)md;
+  void *result;
+  if (is_mdelem_static(md)) {
+    return (void *)grpc_static_mdelem_user_data[md - grpc_static_mdelem_table];
+  }
+  if (gpr_atm_acq_load(&im->destroy_user_data) == (gpr_atm)destroy_func) {
+    return (void *)gpr_atm_no_barrier_load(&im->user_data);
+  } else {
+    return NULL;
   }
-  GPR_UNREACHABLE_CODE(return NULL);
+  return result;
 }
 
-void *grpc_mdelem_set_user_data(grpc_mdelem md, void (*destroy_func)(void *),
+void *grpc_mdelem_set_user_data(grpc_mdelem *md, void (*destroy_func)(void *),
                                 void *user_data) {
-  switch (GRPC_MDELEM_STORAGE(md)) {
-    case GRPC_MDELEM_STORAGE_EXTERNAL:
-    case GRPC_MDELEM_STORAGE_ALLOCATED:
+  internal_metadata *im = (internal_metadata *)md;
+  GPR_ASSERT(!is_mdelem_static(md));
+  GPR_ASSERT((user_data == NULL) == (destroy_func == NULL));
+  gpr_mu_lock(&im->mu_user_data);
+  if (gpr_atm_no_barrier_load(&im->destroy_user_data)) {
+    /* user data can only be set once */
+    gpr_mu_unlock(&im->mu_user_data);
+    if (destroy_func != NULL) {
       destroy_func(user_data);
-      return NULL;
-    case GRPC_MDELEM_STORAGE_STATIC:
-      destroy_func(user_data);
-      return (void *)grpc_static_mdelem_user_data[GRPC_MDELEM_DATA(md) -
-                                                  grpc_static_mdelem_table];
-    case GRPC_MDELEM_STORAGE_INTERNED: {
-      interned_metadata *im = (interned_metadata *)GRPC_MDELEM_DATA(md);
-      GPR_ASSERT(!is_mdelem_static(md));
-      GPR_ASSERT((user_data == NULL) == (destroy_func == NULL));
-      gpr_mu_lock(&im->mu_user_data);
-      if (gpr_atm_no_barrier_load(&im->destroy_user_data)) {
-        /* user data can only be set once */
-        gpr_mu_unlock(&im->mu_user_data);
-        if (destroy_func != NULL) {
-          destroy_func(user_data);
-        }
-        return (void *)gpr_atm_no_barrier_load(&im->user_data);
-      }
-      gpr_atm_no_barrier_store(&im->user_data, (gpr_atm)user_data);
-      gpr_atm_rel_store(&im->destroy_user_data, (gpr_atm)destroy_func);
-      gpr_mu_unlock(&im->mu_user_data);
-      return user_data;
     }
+    return (void *)gpr_atm_no_barrier_load(&im->user_data);
   }
-  GPR_UNREACHABLE_CODE(return NULL);
+  gpr_atm_no_barrier_store(&im->user_data, (gpr_atm)user_data);
+  gpr_atm_rel_store(&im->destroy_user_data, (gpr_atm)destroy_func);
+  gpr_mu_unlock(&im->mu_user_data);
+  return user_data;
 }
 
-bool grpc_mdelem_eq(grpc_mdelem a, grpc_mdelem b) {
-  if (a.payload == b.payload) return true;
-  if (GRPC_MDELEM_IS_INTERNED(a) && GRPC_MDELEM_IS_INTERNED(b)) return false;
-  if (GRPC_MDISNULL(a) || GRPC_MDISNULL(b)) return false;
-  return grpc_slice_eq(GRPC_MDKEY(a), GRPC_MDKEY(b)) &&
-         grpc_slice_eq(GRPC_MDVALUE(a), GRPC_MDVALUE(b));
+grpc_slice grpc_mdstr_as_base64_encoded_and_huffman_compressed(grpc_mdstr *gs) {
+  internal_string *s = (internal_string *)gs;
+  grpc_slice slice;
+  strtab_shard *shard =
+      &g_strtab_shard[SHARD_IDX(s->hash, LOG2_STRTAB_SHARD_COUNT)];
+  gpr_mu_lock(&shard->mu);
+  if (!s->has_base64_and_huffman_encoded) {
+    s->base64_and_huffman =
+        grpc_chttp2_base64_encode_and_huffman_compress(s->slice);
+    s->has_base64_and_huffman_encoded = 1;
+  }
+  slice = s->base64_and_huffman;
+  gpr_mu_unlock(&shard->mu);
+  return slice;
 }
diff --git a/src/core/lib/transport/metadata.h b/src/core/lib/transport/metadata.h
index f4ba86c854..991eee96f1 100644
--- a/src/core/lib/transport/metadata.h
+++ b/src/core/lib/transport/metadata.h
@@ -34,7 +34,6 @@
 #ifndef GRPC_CORE_LIB_TRANSPORT_METADATA_H
 #define GRPC_CORE_LIB_TRANSPORT_METADATA_H
 
-#include <grpc/grpc.h>
 #include <grpc/slice.h>
 #include <grpc/support/useful.h>
 
@@ -75,110 +74,110 @@ extern "C" {
    declared here - in which case those functions are effectively no-ops. */
 
 /* Forward declarations */
+typedef struct grpc_mdstr grpc_mdstr;
 typedef struct grpc_mdelem grpc_mdelem;
 
-/* if changing this, make identical changes in:
-   - interned_metadata, allocated_metadata in metadata.c
-   - grpc_metadata in grpc_types.h */
-typedef struct grpc_mdelem_data {
-  const grpc_slice key;
-  const grpc_slice value;
+/* if changing this, make identical changes in internal_string in metadata.c */
+struct grpc_mdstr {
+  const grpc_slice slice;
+  const uint32_t hash;
   /* there is a private part to this in metadata.c */
-} grpc_mdelem_data;
-
-/* GRPC_MDELEM_STORAGE_* enum values that can be treated as interned always have
-   this bit set in their integer value */
-#define GRPC_MDELEM_STORAGE_INTERNED_BIT 1
-
-typedef enum {
-  /* memory pointed to by grpc_mdelem::payload is owned by an external system */
-  GRPC_MDELEM_STORAGE_EXTERNAL = 0,
-  /* memory pointed to by grpc_mdelem::payload is interned by the metadata
-     system */
-  GRPC_MDELEM_STORAGE_INTERNED = GRPC_MDELEM_STORAGE_INTERNED_BIT,
-  /* memory pointed to by grpc_mdelem::payload is allocated by the metadata
-     system */
-  GRPC_MDELEM_STORAGE_ALLOCATED = 2,
-  /* memory is in the static metadata table */
-  GRPC_MDELEM_STORAGE_STATIC = 2 | GRPC_MDELEM_STORAGE_INTERNED_BIT,
-} grpc_mdelem_data_storage;
+};
 
+/* if changing this, make identical changes in internal_metadata in
+   metadata.c */
 struct grpc_mdelem {
-  /* a grpc_mdelem_data* generally, with the two lower bits signalling memory
-     ownership as per grpc_mdelem_data_storage */
-  uintptr_t payload;
+  grpc_mdstr *const key;
+  grpc_mdstr *const value;
+  /* there is a private part to this in metadata.c */
 };
 
-#define GRPC_MDELEM_DATA(md) \
-  ((grpc_mdelem_data *)((md).payload & ~(uintptr_t)3))
-#define GRPC_MDELEM_STORAGE(md) \
-  ((grpc_mdelem_data_storage)((md).payload & (uintptr_t)3))
-#define GRPC_MAKE_MDELEM(data, storage) \
-  ((grpc_mdelem){((uintptr_t)(data)) | ((uintptr_t)storage)})
-#define GRPC_MDELEM_IS_INTERNED(md)          \
-  ((grpc_mdelem_data_storage)((md).payload & \
-                              (uintptr_t)GRPC_MDELEM_STORAGE_INTERNED_BIT))
-
+void grpc_test_only_set_metadata_hash_seed(uint32_t seed);
+
+/* Constructors for grpc_mdstr instances; take a variety of data types that
+   clients may have handy */
+grpc_mdstr *grpc_mdstr_from_string(const char *str);
+/* Unrefs the slice. */
+grpc_mdstr *grpc_mdstr_from_slice(grpc_exec_ctx *exec_ctx, grpc_slice slice);
+grpc_mdstr *grpc_mdstr_from_buffer(const uint8_t *str, size_t length);
+
+/* Returns a borrowed slice from the mdstr with its contents base64 encoded
+   and huffman compressed */
+grpc_slice grpc_mdstr_as_base64_encoded_and_huffman_compressed(grpc_mdstr *str);
+
+/* Constructors for grpc_mdelem instances; take a variety of data types that
+   clients may have handy */
+grpc_mdelem *grpc_mdelem_from_metadata_strings(grpc_exec_ctx *exec_ctx,
+                                               grpc_mdstr *key,
+                                               grpc_mdstr *value);
+grpc_mdelem *grpc_mdelem_from_strings(grpc_exec_ctx *exec_ctx, const char *key,
+                                      const char *value);
 /* Unrefs the slices. */
-grpc_mdelem grpc_mdelem_from_slices(grpc_exec_ctx *exec_ctx, grpc_slice key,
-                                    grpc_slice value);
-
-/* Cheaply convert a grpc_metadata to a grpc_mdelem; may use the grpc_metadata
-   object as backing storage (so lifetimes should align) */
-grpc_mdelem grpc_mdelem_from_grpc_metadata(grpc_exec_ctx *exec_ctx,
-                                           grpc_metadata *metadata);
+grpc_mdelem *grpc_mdelem_from_slices(grpc_exec_ctx *exec_ctx, grpc_slice key,
+                                     grpc_slice value);
+grpc_mdelem *grpc_mdelem_from_string_and_buffer(grpc_exec_ctx *exec_ctx,
+                                                const char *key,
+                                                const uint8_t *value,
+                                                size_t value_length);
 
-/* Does not unref the slices; if a new non-interned mdelem is needed, allocates
-   one if compatible_external_backing_store is NULL, or uses
-   compatible_external_backing_store if it is non-NULL (in which case it's the
-   users responsibility to ensure that it outlives usage) */
-grpc_mdelem grpc_mdelem_create(
-    grpc_exec_ctx *exec_ctx, grpc_slice key, grpc_slice value,
-    grpc_mdelem_data *compatible_external_backing_store);
-
-bool grpc_mdelem_eq(grpc_mdelem a, grpc_mdelem b);
-
-size_t grpc_mdelem_get_size_in_hpack_table(grpc_mdelem elem);
+size_t grpc_mdelem_get_size_in_hpack_table(grpc_mdelem *elem);
 
 /* Mutator and accessor for grpc_mdelem user data. The destructor function
    is used as a type tag and is checked during user_data fetch. */
-void *grpc_mdelem_get_user_data(grpc_mdelem md,
+void *grpc_mdelem_get_user_data(grpc_mdelem *md,
                                 void (*if_destroy_func)(void *));
-void *grpc_mdelem_set_user_data(grpc_mdelem md, void (*destroy_func)(void *),
+void *grpc_mdelem_set_user_data(grpc_mdelem *md, void (*destroy_func)(void *),
                                 void *user_data);
 
 /* Reference counting */
 //#define GRPC_METADATA_REFCOUNT_DEBUG
 #ifdef GRPC_METADATA_REFCOUNT_DEBUG
+#define GRPC_MDSTR_REF(s) grpc_mdstr_ref((s), __FILE__, __LINE__)
+#define GRPC_MDSTR_UNREF(exec_ctx, s) \
+  grpc_mdstr_unref((exec_ctx), (s), __FILE__, __LINE__)
 #define GRPC_MDELEM_REF(s) grpc_mdelem_ref((s), __FILE__, __LINE__)
 #define GRPC_MDELEM_UNREF(exec_ctx, s) \
   grpc_mdelem_unref((exec_ctx), (s), __FILE__, __LINE__)
-grpc_mdelem grpc_mdelem_ref(grpc_mdelem md, const char *file, int line);
-void grpc_mdelem_unref(grpc_exec_ctx *exec_ctx, grpc_mdelem md,
+grpc_mdstr *grpc_mdstr_ref(grpc_mdstr *s, const char *file, int line);
+void grpc_mdstr_unref(grpc_exec_ctx *exec_ctx, grpc_mdstr *s, const char *file,
+                      int line);
+grpc_mdelem *grpc_mdelem_ref(grpc_mdelem *md, const char *file, int line);
+void grpc_mdelem_unref(grpc_exec_ctx *exec_ctx, grpc_mdelem *md,
                        const char *file, int line);
 #else
+#define GRPC_MDSTR_REF(s) grpc_mdstr_ref((s))
+#define GRPC_MDSTR_UNREF(exec_ctx, s) grpc_mdstr_unref((exec_ctx), (s))
 #define GRPC_MDELEM_REF(s) grpc_mdelem_ref((s))
 #define GRPC_MDELEM_UNREF(exec_ctx, s) grpc_mdelem_unref((exec_ctx), (s))
-grpc_mdelem grpc_mdelem_ref(grpc_mdelem md);
-void grpc_mdelem_unref(grpc_exec_ctx *exec_ctx, grpc_mdelem md);
+grpc_mdstr *grpc_mdstr_ref(grpc_mdstr *s);
+void grpc_mdstr_unref(grpc_exec_ctx *exec_ctx, grpc_mdstr *s);
+grpc_mdelem *grpc_mdelem_ref(grpc_mdelem *md);
+void grpc_mdelem_unref(grpc_exec_ctx *exec_ctx, grpc_mdelem *md);
 #endif
 
-#define GRPC_MDKEY(md) (GRPC_MDELEM_DATA(md)->key)
-#define GRPC_MDVALUE(md) (GRPC_MDELEM_DATA(md)->value)
+/* Recover a char* from a grpc_mdstr. The returned string is null terminated.
+   Does not promise that the returned string has no embedded nulls however. */
+const char *grpc_mdstr_as_c_string(const grpc_mdstr *s);
 
-#define GRPC_MDNULL GRPC_MAKE_MDELEM(NULL, GRPC_MDELEM_STORAGE_EXTERNAL)
-#define GRPC_MDISNULL(md) (GRPC_MDELEM_DATA(md) == NULL)
+#define GRPC_MDSTR_LENGTH(s) (GRPC_SLICE_LENGTH(s->slice))
 
 /* We add 32 bytes of padding as per RFC-7540 section 6.5.2. */
-#define GRPC_MDELEM_LENGTH(e)                                                  \
-  (GRPC_SLICE_LENGTH(GRPC_MDKEY((e))) + GRPC_SLICE_LENGTH(GRPC_MDVALUE((e))) + \
-   32)
+#define GRPC_MDELEM_LENGTH(e) \
+  (GRPC_MDSTR_LENGTH((e)->key) + GRPC_MDSTR_LENGTH((e)->value) + 32)
+
+int grpc_mdstr_is_legal_header(grpc_mdstr *s);
+int grpc_mdstr_is_legal_nonbin_header(grpc_mdstr *s);
+int grpc_mdstr_is_bin_suffixed(grpc_mdstr *s);
 
 #define GRPC_MDSTR_KV_HASH(k_hash, v_hash) (GPR_ROTL((k_hash), 2) ^ (v_hash))
 
 void grpc_mdctx_global_init(void);
 void grpc_mdctx_global_shutdown(grpc_exec_ctx *exec_ctx);
 
+/* Implementation provided by chttp2_transport */
+extern grpc_slice (*grpc_chttp2_base64_encode_and_huffman_compress)(
+    grpc_slice input);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/core/lib/transport/metadata_batch.c b/src/core/lib/transport/metadata_batch.c
index 95b71d33d7..b62ecc3aa6 100644
--- a/src/core/lib/transport/metadata_batch.c
+++ b/src/core/lib/transport/metadata_batch.c
@@ -40,8 +40,6 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/profiling/timers.h"
-#include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 
 static void assert_valid_list(grpc_mdelem_list *list) {
 #ifndef NDEBUG
@@ -53,34 +51,16 @@ static void assert_valid_list(grpc_mdelem_list *list) {
   GPR_ASSERT(list->tail->next == NULL);
   GPR_ASSERT((list->head == list->tail) == (list->head->next == NULL));
 
-  size_t verified_count = 0;
   for (l = list->head; l; l = l->next) {
-    GPR_ASSERT(!GRPC_MDISNULL(l->md));
+    GPR_ASSERT(l->md);
     GPR_ASSERT((l->prev == NULL) == (l == list->head));
     GPR_ASSERT((l->next == NULL) == (l == list->tail));
     if (l->next) GPR_ASSERT(l->next->prev == l);
     if (l->prev) GPR_ASSERT(l->prev->next == l);
-    verified_count++;
   }
-  GPR_ASSERT(list->count == verified_count);
 #endif /* NDEBUG */
 }
 
-static void assert_valid_callouts(grpc_exec_ctx *exec_ctx,
-                                  grpc_metadata_batch *batch) {
-#ifndef NDEBUG
-  for (grpc_linked_mdelem *l = batch->list.head; l != NULL; l = l->next) {
-    grpc_slice key_interned = grpc_slice_intern(GRPC_MDKEY(l->md));
-    grpc_metadata_batch_callouts_index callout_idx =
-        GRPC_BATCH_INDEX_OF(key_interned);
-    if (callout_idx != GRPC_BATCH_CALLOUTS_COUNT) {
-      GPR_ASSERT(batch->idx.array[callout_idx] == l);
-    }
-    grpc_slice_unref_internal(exec_ctx, key_interned);
-  }
-#endif
-}
-
 #ifndef NDEBUG
 void grpc_metadata_batch_assert_ok(grpc_metadata_batch *batch) {
   assert_valid_list(&batch->list);
@@ -88,7 +68,7 @@ void grpc_metadata_batch_assert_ok(grpc_metadata_batch *batch) {
 #endif /* NDEBUG */
 
 void grpc_metadata_batch_init(grpc_metadata_batch *batch) {
-  memset(batch, 0, sizeof(*batch));
+  batch->list.head = batch->list.tail = NULL;
   batch->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
 }
 
@@ -100,58 +80,17 @@ void grpc_metadata_batch_destroy(grpc_exec_ctx *exec_ctx,
   }
 }
 
-grpc_error *grpc_attach_md_to_error(grpc_error *src, grpc_mdelem md) {
-  char *k = grpc_slice_to_c_string(GRPC_MDKEY(md));
-  char *v = grpc_slice_to_c_string(GRPC_MDVALUE(md));
-  grpc_error *out = grpc_error_set_str(
-      grpc_error_set_str(src, GRPC_ERROR_STR_KEY, k), GRPC_ERROR_STR_VALUE, v);
-  gpr_free(k);
-  gpr_free(v);
-  return out;
-}
-
-static grpc_error *maybe_link_callout(grpc_metadata_batch *batch,
-                                      grpc_linked_mdelem *storage)
-    GRPC_MUST_USE_RESULT;
-
-static grpc_error *maybe_link_callout(grpc_metadata_batch *batch,
-                                      grpc_linked_mdelem *storage) {
-  grpc_metadata_batch_callouts_index idx =
-      GRPC_BATCH_INDEX_OF(GRPC_MDKEY(storage->md));
-  if (idx == GRPC_BATCH_CALLOUTS_COUNT) {
-    return GRPC_ERROR_NONE;
-  }
-  if (batch->idx.array[idx] == NULL) {
-    batch->idx.array[idx] = storage;
-    return GRPC_ERROR_NONE;
-  }
-  return grpc_attach_md_to_error(
-      GRPC_ERROR_CREATE("Unallowed duplicate metadata"), storage->md);
-}
-
-static void maybe_unlink_callout(grpc_metadata_batch *batch,
-                                 grpc_linked_mdelem *storage) {
-  grpc_metadata_batch_callouts_index idx =
-      GRPC_BATCH_INDEX_OF(GRPC_MDKEY(storage->md));
-  if (idx == GRPC_BATCH_CALLOUTS_COUNT) {
-    return;
-  }
-  GPR_ASSERT(batch->idx.array[idx] != NULL);
-  batch->idx.array[idx] = NULL;
-}
-
-grpc_error *grpc_metadata_batch_add_head(grpc_exec_ctx *exec_ctx,
-                                         grpc_metadata_batch *batch,
-                                         grpc_linked_mdelem *storage,
-                                         grpc_mdelem elem_to_add) {
-  GPR_ASSERT(!GRPC_MDISNULL(elem_to_add));
+void grpc_metadata_batch_add_head(grpc_metadata_batch *batch,
+                                  grpc_linked_mdelem *storage,
+                                  grpc_mdelem *elem_to_add) {
+  GPR_ASSERT(elem_to_add);
   storage->md = elem_to_add;
-  return grpc_metadata_batch_link_head(exec_ctx, batch, storage);
+  grpc_metadata_batch_link_head(batch, storage);
 }
 
 static void link_head(grpc_mdelem_list *list, grpc_linked_mdelem *storage) {
   assert_valid_list(list);
-  GPR_ASSERT(!GRPC_MDISNULL(storage->md));
+  GPR_ASSERT(storage->md);
   storage->prev = NULL;
   storage->next = list->head;
   if (list->head != NULL) {
@@ -160,36 +99,25 @@ static void link_head(grpc_mdelem_list *list, grpc_linked_mdelem *storage) {
     list->tail = storage;
   }
   list->head = storage;
-  list->count++;
   assert_valid_list(list);
 }
 
-grpc_error *grpc_metadata_batch_link_head(grpc_exec_ctx *exec_ctx,
-                                          grpc_metadata_batch *batch,
-                                          grpc_linked_mdelem *storage) {
-  assert_valid_callouts(exec_ctx, batch);
-  grpc_error *err = maybe_link_callout(batch, storage);
-  if (err != GRPC_ERROR_NONE) {
-    assert_valid_callouts(exec_ctx, batch);
-    return err;
-  }
+void grpc_metadata_batch_link_head(grpc_metadata_batch *batch,
+                                   grpc_linked_mdelem *storage) {
   link_head(&batch->list, storage);
-  assert_valid_callouts(exec_ctx, batch);
-  return GRPC_ERROR_NONE;
 }
 
-grpc_error *grpc_metadata_batch_add_tail(grpc_exec_ctx *exec_ctx,
-                                         grpc_metadata_batch *batch,
-                                         grpc_linked_mdelem *storage,
-                                         grpc_mdelem elem_to_add) {
-  GPR_ASSERT(!GRPC_MDISNULL(elem_to_add));
+void grpc_metadata_batch_add_tail(grpc_metadata_batch *batch,
+                                  grpc_linked_mdelem *storage,
+                                  grpc_mdelem *elem_to_add) {
+  GPR_ASSERT(elem_to_add);
   storage->md = elem_to_add;
-  return grpc_metadata_batch_link_tail(exec_ctx, batch, storage);
+  grpc_metadata_batch_link_tail(batch, storage);
 }
 
 static void link_tail(grpc_mdelem_list *list, grpc_linked_mdelem *storage) {
   assert_valid_list(list);
-  GPR_ASSERT(!GRPC_MDISNULL(storage->md));
+  GPR_ASSERT(storage->md);
   storage->prev = list->tail;
   storage->next = NULL;
   storage->reserved = NULL;
@@ -199,82 +127,70 @@ static void link_tail(grpc_mdelem_list *list, grpc_linked_mdelem *storage) {
     list->head = storage;
   }
   list->tail = storage;
-  list->count++;
   assert_valid_list(list);
 }
 
-grpc_error *grpc_metadata_batch_link_tail(grpc_exec_ctx *exec_ctx,
-                                          grpc_metadata_batch *batch,
-                                          grpc_linked_mdelem *storage) {
-  assert_valid_callouts(exec_ctx, batch);
-  grpc_error *err = maybe_link_callout(batch, storage);
-  if (err != GRPC_ERROR_NONE) {
-    assert_valid_callouts(exec_ctx, batch);
-    return err;
-  }
+void grpc_metadata_batch_link_tail(grpc_metadata_batch *batch,
+                                   grpc_linked_mdelem *storage) {
   link_tail(&batch->list, storage);
-  assert_valid_callouts(exec_ctx, batch);
-  return GRPC_ERROR_NONE;
 }
 
-static void unlink_storage(grpc_mdelem_list *list,
-                           grpc_linked_mdelem *storage) {
-  assert_valid_list(list);
-  if (storage->prev != NULL) {
-    storage->prev->next = storage->next;
-  } else {
-    list->head = storage->next;
-  }
-  if (storage->next != NULL) {
-    storage->next->prev = storage->prev;
-  } else {
-    list->tail = storage->prev;
-  }
-  list->count--;
-  assert_valid_list(list);
+void grpc_metadata_batch_move(grpc_metadata_batch *dst,
+                              grpc_metadata_batch *src) {
+  *dst = *src;
+  memset(src, 0, sizeof(grpc_metadata_batch));
 }
 
-void grpc_metadata_batch_remove(grpc_exec_ctx *exec_ctx,
+void grpc_metadata_batch_filter(grpc_exec_ctx *exec_ctx,
                                 grpc_metadata_batch *batch,
-                                grpc_linked_mdelem *storage) {
-  assert_valid_callouts(exec_ctx, batch);
-  maybe_unlink_callout(batch, storage);
-  unlink_storage(&batch->list, storage);
-  GRPC_MDELEM_UNREF(exec_ctx, storage->md);
-  assert_valid_callouts(exec_ctx, batch);
-}
+                                grpc_mdelem *(*filter)(grpc_exec_ctx *exec_ctx,
+                                                       void *user_data,
+                                                       grpc_mdelem *elem),
+                                void *user_data) {
+  grpc_linked_mdelem *l;
+  grpc_linked_mdelem *next;
 
-void grpc_metadata_batch_set_value(grpc_exec_ctx *exec_ctx,
-                                   grpc_linked_mdelem *storage,
-                                   grpc_slice value) {
-  grpc_mdelem old = storage->md;
-  grpc_mdelem new = grpc_mdelem_from_slices(
-      exec_ctx, grpc_slice_ref_internal(GRPC_MDKEY(old)), value);
-  storage->md = new;
-  GRPC_MDELEM_UNREF(exec_ctx, old);
-}
+  GPR_TIMER_BEGIN("grpc_metadata_batch_filter", 0);
 
-grpc_error *grpc_metadata_batch_substitute(grpc_exec_ctx *exec_ctx,
-                                           grpc_metadata_batch *batch,
-                                           grpc_linked_mdelem *storage,
-                                           grpc_mdelem new) {
-  grpc_error *error = GRPC_ERROR_NONE;
-  grpc_mdelem old = storage->md;
-  if (!grpc_slice_eq(GRPC_MDKEY(new), GRPC_MDKEY(old))) {
-    maybe_unlink_callout(batch, storage);
-    storage->md = new;
-    error = maybe_link_callout(batch, storage);
-  } else {
-    storage->md = new;
+  assert_valid_list(&batch->list);
+  for (l = batch->list.head; l; l = next) {
+    grpc_mdelem *orig = l->md;
+    grpc_mdelem *filt = filter(exec_ctx, user_data, orig);
+    next = l->next;
+    if (filt == NULL) {
+      if (l->prev) {
+        l->prev->next = l->next;
+      }
+      if (l->next) {
+        l->next->prev = l->prev;
+      }
+      if (batch->list.head == l) {
+        batch->list.head = l->next;
+      }
+      if (batch->list.tail == l) {
+        batch->list.tail = l->prev;
+      }
+      assert_valid_list(&batch->list);
+      GRPC_MDELEM_UNREF(exec_ctx, l->md);
+    } else if (filt != orig) {
+      GRPC_MDELEM_UNREF(exec_ctx, orig);
+      l->md = filt;
+    }
   }
-  GRPC_MDELEM_UNREF(exec_ctx, old);
-  return error;
+  assert_valid_list(&batch->list);
+
+  GPR_TIMER_END("grpc_metadata_batch_filter", 0);
+}
+
+static grpc_mdelem *no_metadata_for_you(grpc_exec_ctx *exec_ctx,
+                                        void *user_data, grpc_mdelem *elem) {
+  return NULL;
 }
 
 void grpc_metadata_batch_clear(grpc_exec_ctx *exec_ctx,
                                grpc_metadata_batch *batch) {
-  grpc_metadata_batch_destroy(exec_ctx, batch);
-  grpc_metadata_batch_init(batch);
+  batch->deadline = gpr_inf_future(GPR_CLOCK_REALTIME);
+  grpc_metadata_batch_filter(exec_ctx, batch, no_metadata_for_you, NULL);
 }
 
 bool grpc_metadata_batch_is_empty(grpc_metadata_batch *batch) {
@@ -291,33 +207,3 @@ size_t grpc_metadata_batch_size(grpc_metadata_batch *batch) {
   }
   return size;
 }
-
-static void add_error(grpc_error **composite, grpc_error *error,
-                      const char *composite_error_string) {
-  if (error == GRPC_ERROR_NONE) return;
-  if (*composite == GRPC_ERROR_NONE) {
-    *composite = GRPC_ERROR_CREATE(composite_error_string);
-  }
-  *composite = grpc_error_add_child(*composite, error);
-}
-
-grpc_error *grpc_metadata_batch_filter(grpc_exec_ctx *exec_ctx,
-                                       grpc_metadata_batch *batch,
-                                       grpc_metadata_batch_filter_func func,
-                                       void *user_data,
-                                       const char *composite_error_string) {
-  grpc_linked_mdelem *l = batch->list.head;
-  grpc_error *error = GRPC_ERROR_NONE;
-  while (l) {
-    grpc_linked_mdelem *next = l->next;
-    grpc_filtered_mdelem new = func(exec_ctx, user_data, l->md);
-    add_error(&error, new.error, composite_error_string);
-    if (GRPC_MDISNULL(new.md)) {
-      grpc_metadata_batch_remove(exec_ctx, batch, l);
-    } else if (new.md.payload != l->md.payload) {
-      grpc_metadata_batch_substitute(exec_ctx, batch, l, new.md);
-    }
-    l = next;
-  }
-  return error;
-}
diff --git a/src/core/lib/transport/metadata_batch.h b/src/core/lib/transport/metadata_batch.h
index 5471539e82..c0bd5174ab 100644
--- a/src/core/lib/transport/metadata_batch.h
+++ b/src/core/lib/transport/metadata_batch.h
@@ -41,21 +41,19 @@
 #include <grpc/support/port_platform.h>
 #include <grpc/support/time.h>
 #include "src/core/lib/transport/metadata.h"
-#include "src/core/lib/transport/static_metadata.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 typedef struct grpc_linked_mdelem {
-  grpc_mdelem md;
+  grpc_mdelem *md;
   struct grpc_linked_mdelem *next;
   struct grpc_linked_mdelem *prev;
   void *reserved;
 } grpc_linked_mdelem;
 
 typedef struct grpc_mdelem_list {
-  size_t count;
   grpc_linked_mdelem *head;
   grpc_linked_mdelem *tail;
 } grpc_mdelem_list;
@@ -63,7 +61,6 @@ typedef struct grpc_mdelem_list {
 typedef struct grpc_metadata_batch {
   /** Metadata elements in this batch */
   grpc_mdelem_list list;
-  grpc_metadata_batch_callouts idx;
   /** Used to calculate grpc-timeout at the point of sending,
       or gpr_inf_future if this batch does not need to send a
       grpc-timeout */
@@ -80,37 +77,25 @@ bool grpc_metadata_batch_is_empty(grpc_metadata_batch *batch);
 /* Returns the transport size of the batch. */
 size_t grpc_metadata_batch_size(grpc_metadata_batch *batch);
 
-/** Remove \a storage from the batch, unreffing the mdelem contained */
-void grpc_metadata_batch_remove(grpc_exec_ctx *exec_ctx,
-                                grpc_metadata_batch *batch,
-                                grpc_linked_mdelem *storage);
-
-/** Substitute a new mdelem for an old value */
-grpc_error *grpc_metadata_batch_substitute(grpc_exec_ctx *exec_ctx,
-                                           grpc_metadata_batch *batch,
-                                           grpc_linked_mdelem *storage,
-                                           grpc_mdelem new_value);
-
-void grpc_metadata_batch_set_value(grpc_exec_ctx *exec_ctx,
-                                   grpc_linked_mdelem *storage,
-                                   grpc_slice value);
+/** Moves the metadata information from \a src to \a dst. Upon return, \a src is
+ * zeroed. */
+void grpc_metadata_batch_move(grpc_metadata_batch *dst,
+                              grpc_metadata_batch *src);
 
 /** Add \a storage to the beginning of \a batch. storage->md is
     assumed to be valid.
     \a storage is owned by the caller and must survive for the
     lifetime of batch. This usually means it should be around
     for the lifetime of the call. */
-grpc_error *grpc_metadata_batch_link_head(
-    grpc_exec_ctx *exec_ctx, grpc_metadata_batch *batch,
-    grpc_linked_mdelem *storage) GRPC_MUST_USE_RESULT;
+void grpc_metadata_batch_link_head(grpc_metadata_batch *batch,
+                                   grpc_linked_mdelem *storage);
 /** Add \a storage to the end of \a batch. storage->md is
     assumed to be valid.
     \a storage is owned by the caller and must survive for the
     lifetime of batch. This usually means it should be around
     for the lifetime of the call. */
-grpc_error *grpc_metadata_batch_link_tail(
-    grpc_exec_ctx *exec_ctx, grpc_metadata_batch *batch,
-    grpc_linked_mdelem *storage) GRPC_MUST_USE_RESULT;
+void grpc_metadata_batch_link_tail(grpc_metadata_batch *batch,
+                                   grpc_linked_mdelem *storage);
 
 /** Add \a elem_to_add as the first element in \a batch, using
     \a storage as backing storage for the linked list element.
@@ -118,38 +103,29 @@ grpc_error *grpc_metadata_batch_link_tail(
     lifetime of batch. This usually means it should be around
     for the lifetime of the call.
     Takes ownership of \a elem_to_add */
-grpc_error *grpc_metadata_batch_add_head(
-    grpc_exec_ctx *exec_ctx, grpc_metadata_batch *batch,
-    grpc_linked_mdelem *storage, grpc_mdelem elem_to_add) GRPC_MUST_USE_RESULT;
+void grpc_metadata_batch_add_head(grpc_metadata_batch *batch,
+                                  grpc_linked_mdelem *storage,
+                                  grpc_mdelem *elem_to_add);
 /** Add \a elem_to_add as the last element in \a batch, using
     \a storage as backing storage for the linked list element.
     \a storage is owned by the caller and must survive for the
     lifetime of batch. This usually means it should be around
     for the lifetime of the call.
     Takes ownership of \a elem_to_add */
-grpc_error *grpc_metadata_batch_add_tail(
-    grpc_exec_ctx *exec_ctx, grpc_metadata_batch *batch,
-    grpc_linked_mdelem *storage, grpc_mdelem elem_to_add) GRPC_MUST_USE_RESULT;
-
-grpc_error *grpc_attach_md_to_error(grpc_error *src, grpc_mdelem md);
-
-typedef struct {
-  grpc_error *error;
-  grpc_mdelem md;
-} grpc_filtered_mdelem;
-
-#define GRPC_FILTERED_ERROR(error) \
-  ((grpc_filtered_mdelem){(error), GRPC_MDNULL})
-#define GRPC_FILTERED_MDELEM(md) ((grpc_filtered_mdelem){GRPC_ERROR_NONE, (md)})
-#define GRPC_FILTERED_REMOVE() \
-  ((grpc_filtered_mdelem){GRPC_ERROR_NONE, GRPC_MDNULL})
-
-typedef grpc_filtered_mdelem (*grpc_metadata_batch_filter_func)(
-    grpc_exec_ctx *exec_ctx, void *user_data, grpc_mdelem elem);
-grpc_error *grpc_metadata_batch_filter(
-    grpc_exec_ctx *exec_ctx, grpc_metadata_batch *batch,
-    grpc_metadata_batch_filter_func func, void *user_data,
-    const char *composite_error_string) GRPC_MUST_USE_RESULT;
+void grpc_metadata_batch_add_tail(grpc_metadata_batch *batch,
+                                  grpc_linked_mdelem *storage,
+                                  grpc_mdelem *elem_to_add);
+
+/** For each element in \a batch, execute \a filter.
+    The return value from \a filter will be substituted for the
+    grpc_mdelem passed to \a filter. If \a filter returns NULL,
+    the element will be moved to the garbage list. */
+void grpc_metadata_batch_filter(grpc_exec_ctx *exec_ctx,
+                                grpc_metadata_batch *batch,
+                                grpc_mdelem *(*filter)(grpc_exec_ctx *exec_ctx,
+                                                       void *user_data,
+                                                       grpc_mdelem *elem),
+                                void *user_data);
 
 #ifndef NDEBUG
 void grpc_metadata_batch_assert_ok(grpc_metadata_batch *comd);
diff --git a/src/core/lib/transport/method_config.c b/src/core/lib/transport/method_config.c
new file mode 100644
index 0000000000..25fb54b37d
--- /dev/null
+++ b/src/core/lib/transport/method_config.c
@@ -0,0 +1,347 @@
+//
+// Copyright 2015, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+#include "src/core/lib/transport/method_config.h"
+
+#include <string.h>
+
+#include <grpc/impl/codegen/grpc_types.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include <grpc/support/time.h>
+
+#include "src/core/lib/transport/mdstr_hash_table.h"
+#include "src/core/lib/transport/metadata.h"
+
+//
+// grpc_method_config
+//
+
+// bool vtable
+
+static void* bool_copy(void* valuep) {
+  bool value = *(bool*)valuep;
+  bool* new_value = gpr_malloc(sizeof(bool));
+  *new_value = value;
+  return new_value;
+}
+
+static int bool_cmp(void* v1, void* v2) {
+  bool b1 = *(bool*)v1;
+  bool b2 = *(bool*)v2;
+  if (!b1 && b2) return -1;
+  if (b1 && !b2) return 1;
+  return 0;
+}
+
+static void free_mem(grpc_exec_ctx* exec_ctx, void* p) { gpr_free(p); }
+
+static grpc_mdstr_hash_table_vtable bool_vtable = {free_mem, bool_copy,
+                                                   bool_cmp};
+
+// timespec vtable
+
+static void* timespec_copy(void* valuep) {
+  gpr_timespec value = *(gpr_timespec*)valuep;
+  gpr_timespec* new_value = gpr_malloc(sizeof(gpr_timespec));
+  *new_value = value;
+  return new_value;
+}
+
+static int timespec_cmp(void* v1, void* v2) {
+  return gpr_time_cmp(*(gpr_timespec*)v1, *(gpr_timespec*)v2);
+}
+
+static grpc_mdstr_hash_table_vtable timespec_vtable = {free_mem, timespec_copy,
+                                                       timespec_cmp};
+
+// int32 vtable
+
+static void* int32_copy(void* valuep) {
+  int32_t value = *(int32_t*)valuep;
+  int32_t* new_value = gpr_malloc(sizeof(int32_t));
+  *new_value = value;
+  return new_value;
+}
+
+static int int32_cmp(void* v1, void* v2) {
+  int32_t i1 = *(int32_t*)v1;
+  int32_t i2 = *(int32_t*)v2;
+  if (i1 < i2) return -1;
+  if (i1 > i2) return 1;
+  return 0;
+}
+
+static grpc_mdstr_hash_table_vtable int32_vtable = {free_mem, int32_copy,
+                                                    int32_cmp};
+
+// Hash table keys.
+#define GRPC_METHOD_CONFIG_WAIT_FOR_READY "grpc.wait_for_ready"  // bool
+#define GRPC_METHOD_CONFIG_TIMEOUT "grpc.timeout"                // gpr_timespec
+#define GRPC_METHOD_CONFIG_MAX_REQUEST_MESSAGE_BYTES \
+  "grpc.max_request_message_bytes"  // int32
+#define GRPC_METHOD_CONFIG_MAX_RESPONSE_MESSAGE_BYTES \
+  "grpc.max_response_message_bytes"  // int32
+
+struct grpc_method_config {
+  grpc_mdstr_hash_table* table;
+  grpc_mdstr* wait_for_ready_key;
+  grpc_mdstr* timeout_key;
+  grpc_mdstr* max_request_message_bytes_key;
+  grpc_mdstr* max_response_message_bytes_key;
+};
+
+grpc_method_config* grpc_method_config_create(
+    bool* wait_for_ready, gpr_timespec* timeout,
+    int32_t* max_request_message_bytes, int32_t* max_response_message_bytes) {
+  grpc_method_config* method_config = gpr_malloc(sizeof(grpc_method_config));
+  memset(method_config, 0, sizeof(grpc_method_config));
+  method_config->wait_for_ready_key =
+      grpc_mdstr_from_string(GRPC_METHOD_CONFIG_WAIT_FOR_READY);
+  method_config->timeout_key =
+      grpc_mdstr_from_string(GRPC_METHOD_CONFIG_TIMEOUT);
+  method_config->max_request_message_bytes_key =
+      grpc_mdstr_from_string(GRPC_METHOD_CONFIG_MAX_REQUEST_MESSAGE_BYTES);
+  method_config->max_response_message_bytes_key =
+      grpc_mdstr_from_string(GRPC_METHOD_CONFIG_MAX_RESPONSE_MESSAGE_BYTES);
+  grpc_mdstr_hash_table_entry entries[4];
+  size_t num_entries = 0;
+  if (wait_for_ready != NULL) {
+    entries[num_entries].key = method_config->wait_for_ready_key;
+    entries[num_entries].value = wait_for_ready;
+    entries[num_entries].vtable = &bool_vtable;
+    ++num_entries;
+  }
+  if (timeout != NULL) {
+    entries[num_entries].key = method_config->timeout_key;
+    entries[num_entries].value = timeout;
+    entries[num_entries].vtable = &timespec_vtable;
+    ++num_entries;
+  }
+  if (max_request_message_bytes != NULL) {
+    entries[num_entries].key = method_config->max_request_message_bytes_key;
+    entries[num_entries].value = max_request_message_bytes;
+    entries[num_entries].vtable = &int32_vtable;
+    ++num_entries;
+  }
+  if (max_response_message_bytes != NULL) {
+    entries[num_entries].key = method_config->max_response_message_bytes_key;
+    entries[num_entries].value = max_response_message_bytes;
+    entries[num_entries].vtable = &int32_vtable;
+    ++num_entries;
+  }
+  method_config->table = grpc_mdstr_hash_table_create(num_entries, entries);
+  return method_config;
+}
+
+grpc_method_config* grpc_method_config_ref(grpc_method_config* method_config) {
+  grpc_mdstr_hash_table_ref(method_config->table);
+  return method_config;
+}
+
+void grpc_method_config_unref(grpc_exec_ctx* exec_ctx,
+                              grpc_method_config* method_config) {
+  if (grpc_mdstr_hash_table_unref(exec_ctx, method_config->table)) {
+    GRPC_MDSTR_UNREF(exec_ctx, method_config->wait_for_ready_key);
+    GRPC_MDSTR_UNREF(exec_ctx, method_config->timeout_key);
+    GRPC_MDSTR_UNREF(exec_ctx, method_config->max_request_message_bytes_key);
+    GRPC_MDSTR_UNREF(exec_ctx, method_config->max_response_message_bytes_key);
+    gpr_free(method_config);
+  }
+}
+
+int grpc_method_config_cmp(const grpc_method_config* method_config1,
+                           const grpc_method_config* method_config2) {
+  return grpc_mdstr_hash_table_cmp(method_config1->table,
+                                   method_config2->table);
+}
+
+const bool* grpc_method_config_get_wait_for_ready(
+    const grpc_method_config* method_config) {
+  return grpc_mdstr_hash_table_get(method_config->table,
+                                   method_config->wait_for_ready_key);
+}
+
+const gpr_timespec* grpc_method_config_get_timeout(
+    const grpc_method_config* method_config) {
+  return grpc_mdstr_hash_table_get(method_config->table,
+                                   method_config->timeout_key);
+}
+
+const int32_t* grpc_method_config_get_max_request_message_bytes(
+    const grpc_method_config* method_config) {
+  return grpc_mdstr_hash_table_get(
+      method_config->table, method_config->max_request_message_bytes_key);
+}
+
+const int32_t* grpc_method_config_get_max_response_message_bytes(
+    const grpc_method_config* method_config) {
+  return grpc_mdstr_hash_table_get(
+      method_config->table, method_config->max_response_message_bytes_key);
+}
+
+//
+// grpc_method_config_table
+//
+
+static void method_config_unref(grpc_exec_ctx* exec_ctx, void* valuep) {
+  grpc_method_config_unref(exec_ctx, valuep);
+}
+
+static void* method_config_ref(void* valuep) {
+  return grpc_method_config_ref(valuep);
+}
+
+static int method_config_cmp(void* valuep1, void* valuep2) {
+  return grpc_method_config_cmp(valuep1, valuep2);
+}
+
+static const grpc_mdstr_hash_table_vtable method_config_table_vtable = {
+    method_config_unref, method_config_ref, method_config_cmp};
+
+grpc_method_config_table* grpc_method_config_table_create(
+    size_t num_entries, grpc_method_config_table_entry* entries) {
+  grpc_mdstr_hash_table_entry* hash_table_entries =
+      gpr_malloc(sizeof(grpc_mdstr_hash_table_entry) * num_entries);
+  for (size_t i = 0; i < num_entries; ++i) {
+    hash_table_entries[i].key = entries[i].method_name;
+    hash_table_entries[i].value = entries[i].method_config;
+    hash_table_entries[i].vtable = &method_config_table_vtable;
+  }
+  grpc_method_config_table* method_config_table =
+      grpc_mdstr_hash_table_create(num_entries, hash_table_entries);
+  gpr_free(hash_table_entries);
+  return method_config_table;
+}
+
+grpc_method_config_table* grpc_method_config_table_ref(
+    grpc_method_config_table* table) {
+  return grpc_mdstr_hash_table_ref(table);
+}
+
+void grpc_method_config_table_unref(grpc_exec_ctx* exec_ctx,
+                                    grpc_method_config_table* table) {
+  grpc_mdstr_hash_table_unref(exec_ctx, table);
+}
+
+int grpc_method_config_table_cmp(const grpc_method_config_table* table1,
+                                 const grpc_method_config_table* table2) {
+  return grpc_mdstr_hash_table_cmp(table1, table2);
+}
+
+void* grpc_method_config_table_get(grpc_exec_ctx* exec_ctx,
+                                   const grpc_mdstr_hash_table* table,
+                                   const grpc_mdstr* path) {
+  void* value = grpc_mdstr_hash_table_get(table, path);
+  // If we didn't find a match for the path, try looking for a wildcard
+  // entry (i.e., change "/service/method" to "/service/*").
+  if (value == NULL) {
+    const char* path_str = grpc_mdstr_as_c_string(path);
+    const char* sep = strrchr(path_str, '/') + 1;
+    const size_t len = (size_t)(sep - path_str);
+    char* buf = gpr_malloc(len + 2);  // '*' and NUL
+    memcpy(buf, path_str, len);
+    buf[len] = '*';
+    buf[len + 1] = '\0';
+    grpc_mdstr* wildcard_path = grpc_mdstr_from_string(buf);
+    gpr_free(buf);
+    value = grpc_mdstr_hash_table_get(table, wildcard_path);
+    GRPC_MDSTR_UNREF(exec_ctx, wildcard_path);
+  }
+  return value;
+}
+
+static void* copy_arg(void* p) { return grpc_method_config_table_ref(p); }
+
+static void destroy_arg(grpc_exec_ctx* exec_ctx, void* p) {
+  grpc_method_config_table_unref(exec_ctx, p);
+}
+
+static int cmp_arg(void* p1, void* p2) {
+  return grpc_method_config_table_cmp(p1, p2);
+}
+
+static grpc_arg_pointer_vtable arg_vtable = {copy_arg, destroy_arg, cmp_arg};
+
+grpc_arg grpc_method_config_table_create_channel_arg(
+    grpc_method_config_table* table) {
+  grpc_arg arg;
+  arg.type = GRPC_ARG_POINTER;
+  arg.key = GRPC_ARG_SERVICE_CONFIG;
+  arg.value.pointer.p = table;
+  arg.value.pointer.vtable = &arg_vtable;
+  return arg;
+}
+
+// State used by convert_entry() below.
+typedef struct conversion_state {
+  void* (*convert_value)(const grpc_method_config* method_config);
+  const grpc_mdstr_hash_table_vtable* vtable;
+  size_t num_entries;
+  grpc_mdstr_hash_table_entry* entries;
+} conversion_state;
+
+// A function to be passed to grpc_mdstr_hash_table_iterate() to create
+// a copy of the entries.
+static void convert_entry(const grpc_mdstr_hash_table_entry* entry,
+                          void* user_data) {
+  conversion_state* state = user_data;
+  state->entries[state->num_entries].key = GRPC_MDSTR_REF(entry->key);
+  state->entries[state->num_entries].value = state->convert_value(entry->value);
+  state->entries[state->num_entries].vtable = state->vtable;
+  ++state->num_entries;
+}
+
+grpc_mdstr_hash_table* grpc_method_config_table_convert(
+    grpc_exec_ctx* exec_ctx, const grpc_method_config_table* table,
+    void* (*convert_value)(const grpc_method_config* method_config),
+    const grpc_mdstr_hash_table_vtable* vtable) {
+  // Create an array of the entries in the table with converted values.
+  conversion_state state;
+  state.convert_value = convert_value;
+  state.vtable = vtable;
+  state.num_entries = 0;
+  state.entries = gpr_malloc(sizeof(grpc_mdstr_hash_table_entry) *
+                             grpc_mdstr_hash_table_num_entries(table));
+  grpc_mdstr_hash_table_iterate(table, convert_entry, &state);
+  // Create a new table based on the array we just constructed.
+  grpc_mdstr_hash_table* new_table =
+      grpc_mdstr_hash_table_create(state.num_entries, state.entries);
+  // Clean up the array.
+  for (size_t i = 0; i < state.num_entries; ++i) {
+    GRPC_MDSTR_UNREF(exec_ctx, state.entries[i].key);
+    vtable->destroy_value(exec_ctx, state.entries[i].value);
+  }
+  gpr_free(state.entries);
+  // Return the new table.
+  return new_table;
+}
diff --git a/src/core/lib/transport/method_config.h b/src/core/lib/transport/method_config.h
new file mode 100644
index 0000000000..d17a493fd4
--- /dev/null
+++ b/src/core/lib/transport/method_config.h
@@ -0,0 +1,139 @@
+//
+// Copyright 2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+#ifndef GRPC_CORE_LIB_TRANSPORT_METHOD_CONFIG_H
+#define GRPC_CORE_LIB_TRANSPORT_METHOD_CONFIG_H
+
+#include <stdbool.h>
+
+#include <grpc/impl/codegen/gpr_types.h>
+#include <grpc/impl/codegen/grpc_types.h>
+
+#include "src/core/lib/transport/mdstr_hash_table.h"
+#include "src/core/lib/transport/metadata.h"
+
+/// Per-method configuration.
+typedef struct grpc_method_config grpc_method_config;
+
+/// Creates a grpc_method_config with the specified parameters.
+/// Any parameter may be NULL to indicate that the value is unset.
+///
+/// \a wait_for_ready indicates whether the client should wait until the
+/// request deadline for the channel to become ready, even if there is a
+/// temporary failure before the deadline while attempting to connect.
+///
+/// \a timeout indicates the timeout for calls.
+///
+/// \a max_request_message_bytes and \a max_response_message_bytes
+/// indicate the maximum sizes of the request (checked when sending) and
+/// response (checked when receiving) messages.
+grpc_method_config* grpc_method_config_create(
+    bool* wait_for_ready, gpr_timespec* timeout,
+    int32_t* max_request_message_bytes, int32_t* max_response_message_bytes);
+
+grpc_method_config* grpc_method_config_ref(grpc_method_config* method_config);
+void grpc_method_config_unref(grpc_exec_ctx* exec_ctx,
+                              grpc_method_config* method_config);
+
+/// Compares two grpc_method_configs.
+/// The sort order is stable but undefined.
+int grpc_method_config_cmp(const grpc_method_config* method_config1,
+                           const grpc_method_config* method_config2);
+
+/// These methods return NULL if the requested field is unset.
+/// The caller does NOT take ownership of the result.
+const bool* grpc_method_config_get_wait_for_ready(
+    const grpc_method_config* method_config);
+const gpr_timespec* grpc_method_config_get_timeout(
+    const grpc_method_config* method_config);
+const int32_t* grpc_method_config_get_max_request_message_bytes(
+    const grpc_method_config* method_config);
+const int32_t* grpc_method_config_get_max_response_message_bytes(
+    const grpc_method_config* method_config);
+
+/// A table of method configs.
+typedef grpc_mdstr_hash_table grpc_method_config_table;
+
+typedef struct grpc_method_config_table_entry {
+  /// The name is of one of the following forms:
+  ///   service/method -- specifies exact service and method name
+  ///   service/*      -- matches all methods for the specified service
+  grpc_mdstr* method_name;
+  grpc_method_config* method_config;
+} grpc_method_config_table_entry;
+
+/// Takes new references to all keys and values in \a entries.
+grpc_method_config_table* grpc_method_config_table_create(
+    size_t num_entries, grpc_method_config_table_entry* entries);
+
+grpc_method_config_table* grpc_method_config_table_ref(
+    grpc_method_config_table* table);
+void grpc_method_config_table_unref(grpc_exec_ctx* exec_ctx,
+                                    grpc_method_config_table* table);
+
+/// Compares two grpc_method_config_tables.
+/// The sort order is stable but undefined.
+int grpc_method_config_table_cmp(const grpc_method_config_table* table1,
+                                 const grpc_method_config_table* table2);
+
+/// Gets the method config for the specified \a path, which should be of
+/// the form "/service/method".
+/// Returns NULL if the method has no config.
+/// Caller does NOT own a reference to the result.
+///
+/// Note: This returns a void* instead of a grpc_method_config* so that
+/// it can also be used for tables constructed via
+/// grpc_method_config_table_convert().
+void* grpc_method_config_table_get(grpc_exec_ctx* exec_ctx,
+                                   const grpc_mdstr_hash_table* table,
+                                   const grpc_mdstr* path);
+
+/// Returns a channel arg containing \a table.
+grpc_arg grpc_method_config_table_create_channel_arg(
+    grpc_method_config_table* table);
+
+/// Generates a new table from \a table whose values are converted to a
+/// new form via the \a convert_value function.  The new table will use
+/// \a vtable for its values.
+///
+/// This is generally used to convert the table's value type from
+/// grpc_method_config to a simple struct containing only the parameters
+/// relevant to a particular filter, thus avoiding the need for a hash
+/// table lookup on the fast path.  In that scenario, \a convert_value
+/// will return a new instance of the struct containing the values from
+/// the grpc_method_config, and \a vtable provides the methods for
+/// operating on the struct type.
+grpc_mdstr_hash_table* grpc_method_config_table_convert(
+    grpc_exec_ctx* exec_ctx, const grpc_method_config_table* table,
+    void* (*convert_value)(const grpc_method_config* method_config),
+    const grpc_mdstr_hash_table_vtable* vtable);
+
+#endif /* GRPC_CORE_LIB_TRANSPORT_METHOD_CONFIG_H */
diff --git a/src/core/lib/transport/service_config.c b/src/core/lib/transport/service_config.c
index 12da2a88fe..552d3ec856 100644
--- a/src/core/lib/transport/service_config.c
+++ b/src/core/lib/transport/service_config.c
@@ -39,10 +39,8 @@
 #include <grpc/support/string_util.h>
 
 #include "src/core/lib/json/json.h"
-#include "src/core/lib/slice/slice_hash_table.h"
-#include "src/core/lib/slice/slice_internal.h"
-#include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
+#include "src/core/lib/transport/mdstr_hash_table.h"
 
 // The main purpose of the code here is to parse the service config in
 // JSON form, which will look like this:
@@ -150,8 +148,8 @@ static char* parse_json_method_name(grpc_json* json) {
 static bool parse_json_method_config(
     grpc_exec_ctx* exec_ctx, grpc_json* json,
     void* (*create_value)(const grpc_json* method_config_json),
-    const grpc_slice_hash_table_vtable* vtable,
-    grpc_slice_hash_table_entry* entries, size_t* idx) {
+    const grpc_mdstr_hash_table_vtable* vtable,
+    grpc_mdstr_hash_table_entry* entries, size_t* idx) {
   // Construct value.
   void* method_config = create_value(json);
   if (method_config == NULL) return false;
@@ -172,7 +170,7 @@ static bool parse_json_method_config(
   if (paths.count == 0) goto done;  // No names specified.
   // Add entry for each path.
   for (size_t i = 0; i < paths.count; ++i) {
-    entries[*idx].key = grpc_slice_from_copied_string(paths.strs[i]);
+    entries[*idx].key = grpc_mdstr_from_string(paths.strs[i]);
     entries[*idx].value = vtable->copy_value(method_config);
     entries[*idx].vtable = vtable;
     ++*idx;
@@ -184,15 +182,15 @@ done:
   return success;
 }
 
-grpc_slice_hash_table* grpc_service_config_create_method_config_table(
+grpc_mdstr_hash_table* grpc_service_config_create_method_config_table(
     grpc_exec_ctx* exec_ctx, const grpc_service_config* service_config,
     void* (*create_value)(const grpc_json* method_config_json),
-    const grpc_slice_hash_table_vtable* vtable) {
+    const grpc_mdstr_hash_table_vtable* vtable) {
   const grpc_json* json = service_config->json_tree;
   // Traverse parsed JSON tree.
   if (json->type != GRPC_JSON_OBJECT || json->key != NULL) return NULL;
   size_t num_entries = 0;
-  grpc_slice_hash_table_entry* entries = NULL;
+  grpc_mdstr_hash_table_entry* entries = NULL;
   for (grpc_json* field = json->child; field != NULL; field = field->next) {
     if (field->key == NULL) return NULL;
     if (strcmp(field->key, "methodConfig") == 0) {
@@ -204,7 +202,7 @@ grpc_slice_hash_table* grpc_service_config_create_method_config_table(
         num_entries += count_names_in_method_config_json(method);
       }
       // Populate method config table entries.
-      entries = gpr_malloc(num_entries * sizeof(grpc_slice_hash_table_entry));
+      entries = gpr_malloc(num_entries * sizeof(grpc_mdstr_hash_table_entry));
       size_t idx = 0;
       for (grpc_json* method = field->child; method != NULL;
            method = method->next) {
@@ -217,12 +215,12 @@ grpc_slice_hash_table* grpc_service_config_create_method_config_table(
     }
   }
   // Instantiate method config table.
-  grpc_slice_hash_table* method_config_table = NULL;
+  grpc_mdstr_hash_table* method_config_table = NULL;
   if (entries != NULL) {
-    method_config_table = grpc_slice_hash_table_create(num_entries, entries);
+    method_config_table = grpc_mdstr_hash_table_create(num_entries, entries);
     // Clean up.
     for (size_t i = 0; i < num_entries; ++i) {
-      grpc_slice_unref_internal(exec_ctx, entries[i].key);
+      GRPC_MDSTR_UNREF(exec_ctx, entries[i].key);
       vtable->destroy_value(exec_ctx, entries[i].value);
     }
     gpr_free(entries);
@@ -231,24 +229,23 @@ grpc_slice_hash_table* grpc_service_config_create_method_config_table(
 }
 
 void* grpc_method_config_table_get(grpc_exec_ctx* exec_ctx,
-                                   const grpc_slice_hash_table* table,
-                                   grpc_slice path) {
-  void* value = grpc_slice_hash_table_get(table, path);
+                                   const grpc_mdstr_hash_table* table,
+                                   const grpc_mdstr* path) {
+  void* value = grpc_mdstr_hash_table_get(table, path);
   // If we didn't find a match for the path, try looking for a wildcard
   // entry (i.e., change "/service/method" to "/service/*").
   if (value == NULL) {
-    char* path_str = grpc_slice_to_c_string(path);
+    const char* path_str = grpc_mdstr_as_c_string(path);
     const char* sep = strrchr(path_str, '/') + 1;
     const size_t len = (size_t)(sep - path_str);
     char* buf = gpr_malloc(len + 2);  // '*' and NUL
     memcpy(buf, path_str, len);
     buf[len] = '*';
     buf[len + 1] = '\0';
-    grpc_slice wildcard_path = grpc_slice_from_copied_string(buf);
+    grpc_mdstr* wildcard_path = grpc_mdstr_from_string(buf);
     gpr_free(buf);
-    value = grpc_slice_hash_table_get(table, wildcard_path);
-    grpc_slice_unref_internal(exec_ctx, wildcard_path);
-    gpr_free(path_str);
+    value = grpc_mdstr_hash_table_get(table, wildcard_path);
+    GRPC_MDSTR_UNREF(exec_ctx, wildcard_path);
   }
   return value;
 }
diff --git a/src/core/lib/transport/service_config.h b/src/core/lib/transport/service_config.h
index cd739a593c..f0897170fa 100644
--- a/src/core/lib/transport/service_config.h
+++ b/src/core/lib/transport/service_config.h
@@ -35,7 +35,7 @@
 #include <grpc/impl/codegen/grpc_types.h>
 
 #include "src/core/lib/json/json.h"
-#include "src/core/lib/slice/slice_hash_table.h"
+#include "src/core/lib/transport/mdstr_hash_table.h"
 
 typedef struct grpc_service_config grpc_service_config;
 
@@ -53,10 +53,10 @@ const char* grpc_service_config_get_lb_policy_name(
 /// returned by \a create_value(), based on data parsed from the JSON tree.
 /// \a vtable provides methods used to manage the values.
 /// Returns NULL on error.
-grpc_slice_hash_table* grpc_service_config_create_method_config_table(
+grpc_mdstr_hash_table* grpc_service_config_create_method_config_table(
     grpc_exec_ctx* exec_ctx, const grpc_service_config* service_config,
     void* (*create_value)(const grpc_json* method_config_json),
-    const grpc_slice_hash_table_vtable* vtable);
+    const grpc_mdstr_hash_table_vtable* vtable);
 
 /// A helper function for looking up values in the table returned by
 /// \a grpc_service_config_create_method_config_table().
@@ -65,7 +65,7 @@ grpc_slice_hash_table* grpc_service_config_create_method_config_table(
 /// Returns NULL if the method has no config.
 /// Caller does NOT own a reference to the result.
 void* grpc_method_config_table_get(grpc_exec_ctx* exec_ctx,
-                                   const grpc_slice_hash_table* table,
-                                   grpc_slice path);
+                                   const grpc_mdstr_hash_table* table,
+                                   const grpc_mdstr* path);
 
 #endif /* GRPC_CORE_LIB_TRANSPORT_SERVICE_CONFIG_H */
diff --git a/src/core/lib/transport/static_metadata.c b/src/core/lib/transport/static_metadata.c
index 5adc3216c9..8b22592b45 100644
--- a/src/core/lib/transport/static_metadata.c
+++ b/src/core/lib/transport/static_metadata.c
@@ -41,770 +41,120 @@
 
 #include "src/core/lib/transport/static_metadata.h"
 
-#include "src/core/lib/slice/slice_internal.h"
-
-static uint8_t g_bytes[] = {
-    58,  112, 97,  116, 104, 58,  109, 101, 116, 104, 111, 100, 58,  115, 116,
-    97,  116, 117, 115, 58,  97,  117, 116, 104, 111, 114, 105, 116, 121, 58,
-    115, 99,  104, 101, 109, 101, 116, 101, 103, 114, 112, 99,  45,  109, 101,
-    115, 115, 97,  103, 101, 103, 114, 112, 99,  45,  115, 116, 97,  116, 117,
-    115, 103, 114, 112, 99,  45,  112, 97,  121, 108, 111, 97,  100, 45,  98,
-    105, 110, 103, 114, 112, 99,  45,  101, 110, 99,  111, 100, 105, 110, 103,
-    103, 114, 112, 99,  45,  97,  99,  99,  101, 112, 116, 45,  101, 110, 99,
-    111, 100, 105, 110, 103, 99,  111, 110, 116, 101, 110, 116, 45,  116, 121,
-    112, 101, 103, 114, 112, 99,  45,  105, 110, 116, 101, 114, 110, 97,  108,
-    45,  101, 110, 99,  111, 100, 105, 110, 103, 45,  114, 101, 113, 117, 101,
-    115, 116, 117, 115, 101, 114, 45,  97,  103, 101, 110, 116, 104, 111, 115,
-    116, 108, 98,  45,  116, 111, 107, 101, 110, 108, 98,  45,  99,  111, 115,
-    116, 45,  98,  105, 110, 103, 114, 112, 99,  45,  116, 105, 109, 101, 111,
-    117, 116, 103, 114, 112, 99,  45,  116, 114, 97,  99,  105, 110, 103, 45,
-    98,  105, 110, 103, 114, 112, 99,  45,  115, 116, 97,  116, 115, 45,  98,
-    105, 110, 103, 114, 112, 99,  46,  119, 97,  105, 116, 95,  102, 111, 114,
-    95,  114, 101, 97,  100, 121, 103, 114, 112, 99,  46,  116, 105, 109, 101,
-    111, 117, 116, 103, 114, 112, 99,  46,  109, 97,  120, 95,  114, 101, 113,
-    117, 101, 115, 116, 95,  109, 101, 115, 115, 97,  103, 101, 95,  98,  121,
-    116, 101, 115, 103, 114, 112, 99,  46,  109, 97,  120, 95,  114, 101, 115,
-    112, 111, 110, 115, 101, 95,  109, 101, 115, 115, 97,  103, 101, 95,  98,
-    121, 116, 101, 115, 47,  103, 114, 112, 99,  46,  108, 98,  46,  118, 49,
-    46,  76,  111, 97,  100, 66,  97,  108, 97,  110, 99,  101, 114, 47,  66,
-    97,  108, 97,  110, 99,  101, 76,  111, 97,  100, 48,  49,  50,  105, 100,
-    101, 110, 116, 105, 116, 121, 103, 122, 105, 112, 100, 101, 102, 108, 97,
-    116, 101, 116, 114, 97,  105, 108, 101, 114, 115, 97,  112, 112, 108, 105,
-    99,  97,  116, 105, 111, 110, 47,  103, 114, 112, 99,  80,  79,  83,  84,
-    50,  48,  48,  52,  48,  52,  104, 116, 116, 112, 104, 116, 116, 112, 115,
-    103, 114, 112, 99,  71,  69,  84,  80,  85,  84,  47,  47,  105, 110, 100,
-    101, 120, 46,  104, 116, 109, 108, 50,  48,  52,  50,  48,  54,  51,  48,
-    52,  52,  48,  48,  53,  48,  48,  97,  99,  99,  101, 112, 116, 45,  99,
-    104, 97,  114, 115, 101, 116, 97,  99,  99,  101, 112, 116, 45,  101, 110,
-    99,  111, 100, 105, 110, 103, 103, 122, 105, 112, 44,  32,  100, 101, 102,
-    108, 97,  116, 101, 97,  99,  99,  101, 112, 116, 45,  108, 97,  110, 103,
-    117, 97,  103, 101, 97,  99,  99,  101, 112, 116, 45,  114, 97,  110, 103,
-    101, 115, 97,  99,  99,  101, 112, 116, 97,  99,  99,  101, 115, 115, 45,
-    99,  111, 110, 116, 114, 111, 108, 45,  97,  108, 108, 111, 119, 45,  111,
-    114, 105, 103, 105, 110, 97,  103, 101, 97,  108, 108, 111, 119, 97,  117,
-    116, 104, 111, 114, 105, 122, 97,  116, 105, 111, 110, 99,  97,  99,  104,
-    101, 45,  99,  111, 110, 116, 114, 111, 108, 99,  111, 110, 116, 101, 110,
-    116, 45,  100, 105, 115, 112, 111, 115, 105, 116, 105, 111, 110, 99,  111,
-    110, 116, 101, 110, 116, 45,  101, 110, 99,  111, 100, 105, 110, 103, 99,
-    111, 110, 116, 101, 110, 116, 45,  108, 97,  110, 103, 117, 97,  103, 101,
-    99,  111, 110, 116, 101, 110, 116, 45,  108, 101, 110, 103, 116, 104, 99,
-    111, 110, 116, 101, 110, 116, 45,  108, 111, 99,  97,  116, 105, 111, 110,
-    99,  111, 110, 116, 101, 110, 116, 45,  114, 97,  110, 103, 101, 99,  111,
-    111, 107, 105, 101, 100, 97,  116, 101, 101, 116, 97,  103, 101, 120, 112,
-    101, 99,  116, 101, 120, 112, 105, 114, 101, 115, 102, 114, 111, 109, 105,
-    102, 45,  109, 97,  116, 99,  104, 105, 102, 45,  109, 111, 100, 105, 102,
-    105, 101, 100, 45,  115, 105, 110, 99,  101, 105, 102, 45,  110, 111, 110,
-    101, 45,  109, 97,  116, 99,  104, 105, 102, 45,  114, 97,  110, 103, 101,
-    105, 102, 45,  117, 110, 109, 111, 100, 105, 102, 105, 101, 100, 45,  115,
-    105, 110, 99,  101, 108, 97,  115, 116, 45,  109, 111, 100, 105, 102, 105,
-    101, 100, 108, 105, 110, 107, 108, 111, 99,  97,  116, 105, 111, 110, 109,
-    97,  120, 45,  102, 111, 114, 119, 97,  114, 100, 115, 112, 114, 111, 120,
-    121, 45,  97,  117, 116, 104, 101, 110, 116, 105, 99,  97,  116, 101, 112,
-    114, 111, 120, 121, 45,  97,  117, 116, 104, 111, 114, 105, 122, 97,  116,
-    105, 111, 110, 114, 97,  110, 103, 101, 114, 101, 102, 101, 114, 101, 114,
-    114, 101, 102, 114, 101, 115, 104, 114, 101, 116, 114, 121, 45,  97,  102,
-    116, 101, 114, 115, 101, 114, 118, 101, 114, 115, 101, 116, 45,  99,  111,
-    111, 107, 105, 101, 115, 116, 114, 105, 99,  116, 45,  116, 114, 97,  110,
-    115, 112, 111, 114, 116, 45,  115, 101, 99,  117, 114, 105, 116, 121, 116,
-    114, 97,  110, 115, 102, 101, 114, 45,  101, 110, 99,  111, 100, 105, 110,
-    103, 118, 97,  114, 121, 118, 105, 97,  119, 119, 119, 45,  97,  117, 116,
-    104, 101, 110, 116, 105, 99,  97,  116, 101, 105, 100, 101, 110, 116, 105,
-    116, 121, 44,  100, 101, 102, 108, 97,  116, 101, 105, 100, 101, 110, 116,
-    105, 116, 121, 44,  103, 122, 105, 112, 100, 101, 102, 108, 97,  116, 101,
-    44,  103, 122, 105, 112, 105, 100, 101, 110, 116, 105, 116, 121, 44,  100,
-    101, 102, 108, 97,  116, 101, 44,  103, 122, 105, 112};
-
-static void static_ref(void *unused) {}
-static void static_unref(grpc_exec_ctx *exec_ctx, void *unused) {}
-static const grpc_slice_refcount_vtable static_sub_vtable = {
-    static_ref, static_unref, grpc_slice_default_eq_impl,
-    grpc_slice_default_hash_impl};
-const grpc_slice_refcount_vtable grpc_static_metadata_vtable = {
-    static_ref, static_unref, grpc_static_slice_eq, grpc_static_slice_hash};
-static grpc_slice_refcount static_sub_refcnt = {&static_sub_vtable,
-                                                &static_sub_refcnt};
-grpc_slice_refcount grpc_static_metadata_refcounts[GRPC_STATIC_MDSTR_COUNT] = {
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-    {&grpc_static_metadata_vtable, &static_sub_refcnt},
-};
-
-const grpc_slice grpc_static_slice_table[GRPC_STATIC_MDSTR_COUNT] = {
-    {.refcount = &grpc_static_metadata_refcounts[0],
-     .data.refcounted = {g_bytes + 0, 5}},
-    {.refcount = &grpc_static_metadata_refcounts[1],
-     .data.refcounted = {g_bytes + 5, 7}},
-    {.refcount = &grpc_static_metadata_refcounts[2],
-     .data.refcounted = {g_bytes + 12, 7}},
-    {.refcount = &grpc_static_metadata_refcounts[3],
-     .data.refcounted = {g_bytes + 19, 10}},
-    {.refcount = &grpc_static_metadata_refcounts[4],
-     .data.refcounted = {g_bytes + 29, 7}},
-    {.refcount = &grpc_static_metadata_refcounts[5],
-     .data.refcounted = {g_bytes + 36, 2}},
-    {.refcount = &grpc_static_metadata_refcounts[6],
-     .data.refcounted = {g_bytes + 38, 12}},
-    {.refcount = &grpc_static_metadata_refcounts[7],
-     .data.refcounted = {g_bytes + 50, 11}},
-    {.refcount = &grpc_static_metadata_refcounts[8],
-     .data.refcounted = {g_bytes + 61, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[9],
-     .data.refcounted = {g_bytes + 77, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[10],
-     .data.refcounted = {g_bytes + 90, 20}},
-    {.refcount = &grpc_static_metadata_refcounts[11],
-     .data.refcounted = {g_bytes + 110, 12}},
-    {.refcount = &grpc_static_metadata_refcounts[12],
-     .data.refcounted = {g_bytes + 122, 30}},
-    {.refcount = &grpc_static_metadata_refcounts[13],
-     .data.refcounted = {g_bytes + 152, 10}},
-    {.refcount = &grpc_static_metadata_refcounts[14],
-     .data.refcounted = {g_bytes + 162, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[15],
-     .data.refcounted = {g_bytes + 166, 8}},
-    {.refcount = &grpc_static_metadata_refcounts[16],
-     .data.refcounted = {g_bytes + 174, 11}},
-    {.refcount = &grpc_static_metadata_refcounts[17],
-     .data.refcounted = {g_bytes + 185, 12}},
-    {.refcount = &grpc_static_metadata_refcounts[18],
-     .data.refcounted = {g_bytes + 197, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[19],
-     .data.refcounted = {g_bytes + 213, 14}},
-    {.refcount = &grpc_static_metadata_refcounts[20],
-     .data.refcounted = {g_bytes + 227, 0}},
-    {.refcount = &grpc_static_metadata_refcounts[21],
-     .data.refcounted = {g_bytes + 227, 19}},
-    {.refcount = &grpc_static_metadata_refcounts[22],
-     .data.refcounted = {g_bytes + 246, 12}},
-    {.refcount = &grpc_static_metadata_refcounts[23],
-     .data.refcounted = {g_bytes + 258, 30}},
-    {.refcount = &grpc_static_metadata_refcounts[24],
-     .data.refcounted = {g_bytes + 288, 31}},
-    {.refcount = &grpc_static_metadata_refcounts[25],
-     .data.refcounted = {g_bytes + 319, 36}},
-    {.refcount = &grpc_static_metadata_refcounts[26],
-     .data.refcounted = {g_bytes + 355, 1}},
-    {.refcount = &grpc_static_metadata_refcounts[27],
-     .data.refcounted = {g_bytes + 356, 1}},
-    {.refcount = &grpc_static_metadata_refcounts[28],
-     .data.refcounted = {g_bytes + 357, 1}},
-    {.refcount = &grpc_static_metadata_refcounts[29],
-     .data.refcounted = {g_bytes + 358, 8}},
-    {.refcount = &grpc_static_metadata_refcounts[30],
-     .data.refcounted = {g_bytes + 366, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[31],
-     .data.refcounted = {g_bytes + 370, 7}},
-    {.refcount = &grpc_static_metadata_refcounts[32],
-     .data.refcounted = {g_bytes + 377, 8}},
-    {.refcount = &grpc_static_metadata_refcounts[33],
-     .data.refcounted = {g_bytes + 385, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[34],
-     .data.refcounted = {g_bytes + 401, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[35],
-     .data.refcounted = {g_bytes + 405, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[36],
-     .data.refcounted = {g_bytes + 408, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[37],
-     .data.refcounted = {g_bytes + 411, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[38],
-     .data.refcounted = {g_bytes + 415, 5}},
-    {.refcount = &grpc_static_metadata_refcounts[39],
-     .data.refcounted = {g_bytes + 420, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[40],
-     .data.refcounted = {g_bytes + 424, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[41],
-     .data.refcounted = {g_bytes + 427, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[42],
-     .data.refcounted = {g_bytes + 430, 1}},
-    {.refcount = &grpc_static_metadata_refcounts[43],
-     .data.refcounted = {g_bytes + 431, 11}},
-    {.refcount = &grpc_static_metadata_refcounts[44],
-     .data.refcounted = {g_bytes + 442, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[45],
-     .data.refcounted = {g_bytes + 445, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[46],
-     .data.refcounted = {g_bytes + 448, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[47],
-     .data.refcounted = {g_bytes + 451, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[48],
-     .data.refcounted = {g_bytes + 454, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[49],
-     .data.refcounted = {g_bytes + 457, 14}},
-    {.refcount = &grpc_static_metadata_refcounts[50],
-     .data.refcounted = {g_bytes + 471, 15}},
-    {.refcount = &grpc_static_metadata_refcounts[51],
-     .data.refcounted = {g_bytes + 486, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[52],
-     .data.refcounted = {g_bytes + 499, 15}},
-    {.refcount = &grpc_static_metadata_refcounts[53],
-     .data.refcounted = {g_bytes + 514, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[54],
-     .data.refcounted = {g_bytes + 527, 6}},
-    {.refcount = &grpc_static_metadata_refcounts[55],
-     .data.refcounted = {g_bytes + 533, 27}},
-    {.refcount = &grpc_static_metadata_refcounts[56],
-     .data.refcounted = {g_bytes + 560, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[57],
-     .data.refcounted = {g_bytes + 563, 5}},
-    {.refcount = &grpc_static_metadata_refcounts[58],
-     .data.refcounted = {g_bytes + 568, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[59],
-     .data.refcounted = {g_bytes + 581, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[60],
-     .data.refcounted = {g_bytes + 594, 19}},
-    {.refcount = &grpc_static_metadata_refcounts[61],
-     .data.refcounted = {g_bytes + 613, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[62],
-     .data.refcounted = {g_bytes + 629, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[63],
-     .data.refcounted = {g_bytes + 645, 14}},
-    {.refcount = &grpc_static_metadata_refcounts[64],
-     .data.refcounted = {g_bytes + 659, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[65],
-     .data.refcounted = {g_bytes + 675, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[66],
-     .data.refcounted = {g_bytes + 688, 6}},
-    {.refcount = &grpc_static_metadata_refcounts[67],
-     .data.refcounted = {g_bytes + 694, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[68],
-     .data.refcounted = {g_bytes + 698, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[69],
-     .data.refcounted = {g_bytes + 702, 6}},
-    {.refcount = &grpc_static_metadata_refcounts[70],
-     .data.refcounted = {g_bytes + 708, 7}},
-    {.refcount = &grpc_static_metadata_refcounts[71],
-     .data.refcounted = {g_bytes + 715, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[72],
-     .data.refcounted = {g_bytes + 719, 8}},
-    {.refcount = &grpc_static_metadata_refcounts[73],
-     .data.refcounted = {g_bytes + 727, 17}},
-    {.refcount = &grpc_static_metadata_refcounts[74],
-     .data.refcounted = {g_bytes + 744, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[75],
-     .data.refcounted = {g_bytes + 757, 8}},
-    {.refcount = &grpc_static_metadata_refcounts[76],
-     .data.refcounted = {g_bytes + 765, 19}},
-    {.refcount = &grpc_static_metadata_refcounts[77],
-     .data.refcounted = {g_bytes + 784, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[78],
-     .data.refcounted = {g_bytes + 797, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[79],
-     .data.refcounted = {g_bytes + 801, 8}},
-    {.refcount = &grpc_static_metadata_refcounts[80],
-     .data.refcounted = {g_bytes + 809, 12}},
-    {.refcount = &grpc_static_metadata_refcounts[81],
-     .data.refcounted = {g_bytes + 821, 18}},
-    {.refcount = &grpc_static_metadata_refcounts[82],
-     .data.refcounted = {g_bytes + 839, 19}},
-    {.refcount = &grpc_static_metadata_refcounts[83],
-     .data.refcounted = {g_bytes + 858, 5}},
-    {.refcount = &grpc_static_metadata_refcounts[84],
-     .data.refcounted = {g_bytes + 863, 7}},
-    {.refcount = &grpc_static_metadata_refcounts[85],
-     .data.refcounted = {g_bytes + 870, 7}},
-    {.refcount = &grpc_static_metadata_refcounts[86],
-     .data.refcounted = {g_bytes + 877, 11}},
-    {.refcount = &grpc_static_metadata_refcounts[87],
-     .data.refcounted = {g_bytes + 888, 6}},
-    {.refcount = &grpc_static_metadata_refcounts[88],
-     .data.refcounted = {g_bytes + 894, 10}},
-    {.refcount = &grpc_static_metadata_refcounts[89],
-     .data.refcounted = {g_bytes + 904, 25}},
-    {.refcount = &grpc_static_metadata_refcounts[90],
-     .data.refcounted = {g_bytes + 929, 17}},
-    {.refcount = &grpc_static_metadata_refcounts[91],
-     .data.refcounted = {g_bytes + 946, 4}},
-    {.refcount = &grpc_static_metadata_refcounts[92],
-     .data.refcounted = {g_bytes + 950, 3}},
-    {.refcount = &grpc_static_metadata_refcounts[93],
-     .data.refcounted = {g_bytes + 953, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[94],
-     .data.refcounted = {g_bytes + 969, 16}},
-    {.refcount = &grpc_static_metadata_refcounts[95],
-     .data.refcounted = {g_bytes + 985, 13}},
-    {.refcount = &grpc_static_metadata_refcounts[96],
-     .data.refcounted = {g_bytes + 998, 12}},
-    {.refcount = &grpc_static_metadata_refcounts[97],
-     .data.refcounted = {g_bytes + 1010, 21}},
-};
+grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 
+grpc_mdelem grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT];
 uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT] = {
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 4, 8, 6, 2, 4, 8, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 4, 6, 6, 8, 8};
-
-static const int8_t elems_r[] = {
-    10, 8,   -3,  0,  9,   21,  -76, 22,  0,   10,  -7,  20, 0,  19, 18, 17,
-    16, 0,   0,   0,  0,   0,   0,   0,   0,   0,   0,   0,  0,  0,  0,  0,
-    0,  0,   0,   0,  0,   0,   0,   0,   0,   0,   0,   0,  0,  0,  0,  0,
-    0,  -49, -50, 16, -52, -53, -54, -54, -55, -56, -57, 0,  38, 37, 36, 35,
-    34, 33,  32,  31, 30,  29,  28,  27,  26,  25,  24,  23, 22, 21, 20, 19,
-    18, 17,  16,  15, 14,  13,  12,  15,  14,  13,  12,  11, 10, 9,  8,  0};
-static uint32_t elems_phash(uint32_t i) {
-  i -= 42;
-  uint32_t x = i % 96;
-  uint32_t y = i / 96;
-  uint32_t h = x;
-  if (y < GPR_ARRAY_SIZE(elems_r)) {
-    uint32_t delta = (uint32_t)elems_r[y];
-    h += delta;
-  }
-  return h;
-}
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
-static const uint16_t elem_keys[] = {
-    1009, 1010, 1011, 240,  241,  242,  243,  244,  138,  139,  42,   43,
-    429,  430,  431,  911,  912,  913,  712,  713,  1098, 522,  714,  1294,
-    1392, 1490, 1588, 4822, 4920, 4951, 5116, 5214, 5312, 1111, 5410, 5508,
-    5606, 5704, 5802, 5900, 5998, 6096, 6194, 6292, 6390, 6488, 6586, 6684,
-    6782, 6880, 6978, 7076, 7174, 7272, 7370, 7468, 7566, 7664, 7762, 7860,
-    7958, 8056, 8154, 8252, 8350, 1074, 1075, 1076, 1077, 8448, 8546, 8644,
-    8742, 8840, 8938, 9036, 9134, 314,  0,    0,    0,    0,    0,    0,
-    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
-    0,    0,    0,    0,    132,  231,  232,  0,    0,    0,    0,    0,
-    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
-    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
-    0};
-static const uint8_t elem_idxs[] = {
-    74,  77,  75,  19,  20,  21,  22,  23,  15,  16,  17,  18,  11,  12,  13,
-    3,   4,   5,   0,   1,   41,  6,   2,   70,  48,  55,  56,  24,  25,  26,
-    27,  28,  29,  7,   30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,
-    42,  43,  44,  45,  46,  47,  49,  50,  51,  52,  53,  54,  57,  58,  59,
-    60,  61,  62,  63,  64,  76,  78,  79,  80,  65,  66,  67,  68,  69,  71,
-    72,  73,  14,  255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
-    255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 8,   9,   10};
+const uint8_t grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2] =
+    {11, 33, 10, 33, 12, 33, 12, 50, 13, 33, 14, 33, 15, 33, 16, 33, 17, 33,
+     19, 33, 20, 33, 21, 33, 22, 33, 23, 33, 24, 33, 25, 33, 26, 33, 27, 33,
+     28, 18, 28, 33, 29, 33, 30, 33, 34, 33, 35, 33, 36, 33, 37, 33, 40, 31,
+     40, 32, 40, 49, 40, 54, 40, 55, 40, 56, 40, 57, 41, 31, 41, 49, 41, 54,
+     46, 0,  46, 1,  46, 2,  51, 33, 58, 33, 59, 33, 60, 33, 61, 33, 62, 33,
+     63, 33, 64, 33, 65, 33, 66, 33, 67, 33, 68, 33, 69, 38, 69, 71, 69, 74,
+     70, 82, 70, 83, 72, 33, 73, 33, 75, 33, 76, 33, 77, 33, 78, 33, 79, 39,
+     79, 52, 79, 53, 80, 33, 81, 33, 84, 3,  84, 4,  84, 5,  84, 6,  84, 7,
+     84, 8,  84, 9,  85, 33, 86, 87, 88, 33, 89, 33, 90, 33, 91, 33, 92, 33};
 
-grpc_mdelem grpc_static_mdelem_for_static_strings(int a, int b) {
-  if (a == -1 || b == -1) return GRPC_MDNULL;
-  uint32_t k = (uint32_t)(a * 98 + b);
-  uint32_t h = elems_phash(k);
-  return elem_keys[h] == k
-             ? GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[elem_idxs[h]],
-                                GRPC_MDELEM_STORAGE_STATIC)
-             : GRPC_MDNULL;
-}
+const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT] = {
+    "0",
+    "1",
+    "2",
+    "200",
+    "204",
+    "206",
+    "304",
+    "400",
+    "404",
+    "500",
+    "accept",
+    "accept-charset",
+    "accept-encoding",
+    "accept-language",
+    "accept-ranges",
+    "access-control-allow-origin",
+    "age",
+    "allow",
+    "application/grpc",
+    ":authority",
+    "authorization",
+    "cache-control",
+    "content-disposition",
+    "content-encoding",
+    "content-language",
+    "content-length",
+    "content-location",
+    "content-range",
+    "content-type",
+    "cookie",
+    "date",
+    "deflate",
+    "deflate,gzip",
+    "",
+    "etag",
+    "expect",
+    "expires",
+    "from",
+    "GET",
+    "grpc",
+    "grpc-accept-encoding",
+    "grpc-encoding",
+    "grpc-internal-encoding-request",
+    "grpc-message",
+    "grpc-payload-bin",
+    "grpc-stats-bin",
+    "grpc-status",
+    "grpc-timeout",
+    "grpc-tracing-bin",
+    "gzip",
+    "gzip, deflate",
+    "host",
+    "http",
+    "https",
+    "identity",
+    "identity,deflate",
+    "identity,deflate,gzip",
+    "identity,gzip",
+    "if-match",
+    "if-modified-since",
+    "if-none-match",
+    "if-range",
+    "if-unmodified-since",
+    "last-modified",
+    "lb-cost-bin",
+    "lb-token",
+    "link",
+    "location",
+    "max-forwards",
+    ":method",
+    ":path",
+    "POST",
+    "proxy-authenticate",
+    "proxy-authorization",
+    "PUT",
+    "range",
+    "referer",
+    "refresh",
+    "retry-after",
+    ":scheme",
+    "server",
+    "set-cookie",
+    "/",
+    "/index.html",
+    ":status",
+    "strict-transport-security",
+    "te",
+    "trailers",
+    "transfer-encoding",
+    "user-agent",
+    "vary",
+    "via",
+    "www-authenticate"};
 
-grpc_mdelem_data grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT] = {
-    {{.refcount = &grpc_static_metadata_refcounts[7],
-      .data.refcounted = {g_bytes + 50, 11}},
-     {.refcount = &grpc_static_metadata_refcounts[26],
-      .data.refcounted = {g_bytes + 355, 1}}},
-    {{.refcount = &grpc_static_metadata_refcounts[7],
-      .data.refcounted = {g_bytes + 50, 11}},
-     {.refcount = &grpc_static_metadata_refcounts[27],
-      .data.refcounted = {g_bytes + 356, 1}}},
-    {{.refcount = &grpc_static_metadata_refcounts[7],
-      .data.refcounted = {g_bytes + 50, 11}},
-     {.refcount = &grpc_static_metadata_refcounts[28],
-      .data.refcounted = {g_bytes + 357, 1}}},
-    {{.refcount = &grpc_static_metadata_refcounts[9],
-      .data.refcounted = {g_bytes + 77, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[29],
-      .data.refcounted = {g_bytes + 358, 8}}},
-    {{.refcount = &grpc_static_metadata_refcounts[9],
-      .data.refcounted = {g_bytes + 77, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[30],
-      .data.refcounted = {g_bytes + 366, 4}}},
-    {{.refcount = &grpc_static_metadata_refcounts[9],
-      .data.refcounted = {g_bytes + 77, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[31],
-      .data.refcounted = {g_bytes + 370, 7}}},
-    {{.refcount = &grpc_static_metadata_refcounts[5],
-      .data.refcounted = {g_bytes + 36, 2}},
-     {.refcount = &grpc_static_metadata_refcounts[32],
-      .data.refcounted = {g_bytes + 377, 8}}},
-    {{.refcount = &grpc_static_metadata_refcounts[11],
-      .data.refcounted = {g_bytes + 110, 12}},
-     {.refcount = &grpc_static_metadata_refcounts[33],
-      .data.refcounted = {g_bytes + 385, 16}}},
-    {{.refcount = &grpc_static_metadata_refcounts[1],
-      .data.refcounted = {g_bytes + 5, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[34],
-      .data.refcounted = {g_bytes + 401, 4}}},
-    {{.refcount = &grpc_static_metadata_refcounts[2],
-      .data.refcounted = {g_bytes + 12, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[35],
-      .data.refcounted = {g_bytes + 405, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[2],
-      .data.refcounted = {g_bytes + 12, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[36],
-      .data.refcounted = {g_bytes + 408, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[4],
-      .data.refcounted = {g_bytes + 29, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[37],
-      .data.refcounted = {g_bytes + 411, 4}}},
-    {{.refcount = &grpc_static_metadata_refcounts[4],
-      .data.refcounted = {g_bytes + 29, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[38],
-      .data.refcounted = {g_bytes + 415, 5}}},
-    {{.refcount = &grpc_static_metadata_refcounts[4],
-      .data.refcounted = {g_bytes + 29, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[39],
-      .data.refcounted = {g_bytes + 420, 4}}},
-    {{.refcount = &grpc_static_metadata_refcounts[3],
-      .data.refcounted = {g_bytes + 19, 10}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[1],
-      .data.refcounted = {g_bytes + 5, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[40],
-      .data.refcounted = {g_bytes + 424, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[1],
-      .data.refcounted = {g_bytes + 5, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[41],
-      .data.refcounted = {g_bytes + 427, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[0],
-      .data.refcounted = {g_bytes + 0, 5}},
-     {.refcount = &grpc_static_metadata_refcounts[42],
-      .data.refcounted = {g_bytes + 430, 1}}},
-    {{.refcount = &grpc_static_metadata_refcounts[0],
-      .data.refcounted = {g_bytes + 0, 5}},
-     {.refcount = &grpc_static_metadata_refcounts[43],
-      .data.refcounted = {g_bytes + 431, 11}}},
-    {{.refcount = &grpc_static_metadata_refcounts[2],
-      .data.refcounted = {g_bytes + 12, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[44],
-      .data.refcounted = {g_bytes + 442, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[2],
-      .data.refcounted = {g_bytes + 12, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[45],
-      .data.refcounted = {g_bytes + 445, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[2],
-      .data.refcounted = {g_bytes + 12, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[46],
-      .data.refcounted = {g_bytes + 448, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[2],
-      .data.refcounted = {g_bytes + 12, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[47],
-      .data.refcounted = {g_bytes + 451, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[2],
-      .data.refcounted = {g_bytes + 12, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[48],
-      .data.refcounted = {g_bytes + 454, 3}}},
-    {{.refcount = &grpc_static_metadata_refcounts[49],
-      .data.refcounted = {g_bytes + 457, 14}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[50],
-      .data.refcounted = {g_bytes + 471, 15}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[50],
-      .data.refcounted = {g_bytes + 471, 15}},
-     {.refcount = &grpc_static_metadata_refcounts[51],
-      .data.refcounted = {g_bytes + 486, 13}}},
-    {{.refcount = &grpc_static_metadata_refcounts[52],
-      .data.refcounted = {g_bytes + 499, 15}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[53],
-      .data.refcounted = {g_bytes + 514, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[54],
-      .data.refcounted = {g_bytes + 527, 6}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[55],
-      .data.refcounted = {g_bytes + 533, 27}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[56],
-      .data.refcounted = {g_bytes + 560, 3}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[57],
-      .data.refcounted = {g_bytes + 563, 5}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[58],
-      .data.refcounted = {g_bytes + 568, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[59],
-      .data.refcounted = {g_bytes + 581, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[60],
-      .data.refcounted = {g_bytes + 594, 19}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[61],
-      .data.refcounted = {g_bytes + 613, 16}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[62],
-      .data.refcounted = {g_bytes + 629, 16}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[63],
-      .data.refcounted = {g_bytes + 645, 14}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[64],
-      .data.refcounted = {g_bytes + 659, 16}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[65],
-      .data.refcounted = {g_bytes + 675, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[11],
-      .data.refcounted = {g_bytes + 110, 12}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[66],
-      .data.refcounted = {g_bytes + 688, 6}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[67],
-      .data.refcounted = {g_bytes + 694, 4}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[68],
-      .data.refcounted = {g_bytes + 698, 4}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[69],
-      .data.refcounted = {g_bytes + 702, 6}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[70],
-      .data.refcounted = {g_bytes + 708, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[71],
-      .data.refcounted = {g_bytes + 715, 4}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[14],
-      .data.refcounted = {g_bytes + 162, 4}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[72],
-      .data.refcounted = {g_bytes + 719, 8}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[73],
-      .data.refcounted = {g_bytes + 727, 17}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[74],
-      .data.refcounted = {g_bytes + 744, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[75],
-      .data.refcounted = {g_bytes + 757, 8}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[76],
-      .data.refcounted = {g_bytes + 765, 19}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[77],
-      .data.refcounted = {g_bytes + 784, 13}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[15],
-      .data.refcounted = {g_bytes + 166, 8}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[16],
-      .data.refcounted = {g_bytes + 174, 11}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[78],
-      .data.refcounted = {g_bytes + 797, 4}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[79],
-      .data.refcounted = {g_bytes + 801, 8}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[80],
-      .data.refcounted = {g_bytes + 809, 12}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[81],
-      .data.refcounted = {g_bytes + 821, 18}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[82],
-      .data.refcounted = {g_bytes + 839, 19}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[83],
-      .data.refcounted = {g_bytes + 858, 5}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[84],
-      .data.refcounted = {g_bytes + 863, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[85],
-      .data.refcounted = {g_bytes + 870, 7}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[86],
-      .data.refcounted = {g_bytes + 877, 11}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[87],
-      .data.refcounted = {g_bytes + 888, 6}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[88],
-      .data.refcounted = {g_bytes + 894, 10}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[89],
-      .data.refcounted = {g_bytes + 904, 25}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[90],
-      .data.refcounted = {g_bytes + 929, 17}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[13],
-      .data.refcounted = {g_bytes + 152, 10}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[91],
-      .data.refcounted = {g_bytes + 946, 4}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[92],
-      .data.refcounted = {g_bytes + 950, 3}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[93],
-      .data.refcounted = {g_bytes + 953, 16}},
-     {.refcount = &grpc_static_metadata_refcounts[20],
-      .data.refcounted = {g_bytes + 227, 0}}},
-    {{.refcount = &grpc_static_metadata_refcounts[10],
-      .data.refcounted = {g_bytes + 90, 20}},
-     {.refcount = &grpc_static_metadata_refcounts[29],
-      .data.refcounted = {g_bytes + 358, 8}}},
-    {{.refcount = &grpc_static_metadata_refcounts[10],
-      .data.refcounted = {g_bytes + 90, 20}},
-     {.refcount = &grpc_static_metadata_refcounts[31],
-      .data.refcounted = {g_bytes + 370, 7}}},
-    {{.refcount = &grpc_static_metadata_refcounts[10],
-      .data.refcounted = {g_bytes + 90, 20}},
-     {.refcount = &grpc_static_metadata_refcounts[94],
-      .data.refcounted = {g_bytes + 969, 16}}},
-    {{.refcount = &grpc_static_metadata_refcounts[10],
-      .data.refcounted = {g_bytes + 90, 20}},
-     {.refcount = &grpc_static_metadata_refcounts[30],
-      .data.refcounted = {g_bytes + 366, 4}}},
-    {{.refcount = &grpc_static_metadata_refcounts[10],
-      .data.refcounted = {g_bytes + 90, 20}},
-     {.refcount = &grpc_static_metadata_refcounts[95],
-      .data.refcounted = {g_bytes + 985, 13}}},
-    {{.refcount = &grpc_static_metadata_refcounts[10],
-      .data.refcounted = {g_bytes + 90, 20}},
-     {.refcount = &grpc_static_metadata_refcounts[96],
-      .data.refcounted = {g_bytes + 998, 12}}},
-    {{.refcount = &grpc_static_metadata_refcounts[10],
-      .data.refcounted = {g_bytes + 90, 20}},
-     {.refcount = &grpc_static_metadata_refcounts[97],
-      .data.refcounted = {g_bytes + 1010, 21}}},
-};
-const uint8_t grpc_static_accept_encoding_metadata[8] = {0,  74, 75, 76,
-                                                         77, 78, 79, 80};
+const uint8_t grpc_static_accept_encoding_metadata[8] = {0,  29, 26, 30,
+                                                         28, 32, 27, 31};
diff --git a/src/core/lib/transport/static_metadata.h b/src/core/lib/transport/static_metadata.h
index 7649ccd5d2..28ad6f2961 100644
--- a/src/core/lib/transport/static_metadata.h
+++ b/src/core/lib/transport/static_metadata.h
@@ -44,521 +44,375 @@
 
 #include "src/core/lib/transport/metadata.h"
 
-#define GRPC_STATIC_MDSTR_COUNT 98
-extern const grpc_slice grpc_static_slice_table[GRPC_STATIC_MDSTR_COUNT];
-/* ":path" */
-#define GRPC_MDSTR_PATH (grpc_static_slice_table[0])
-/* ":method" */
-#define GRPC_MDSTR_METHOD (grpc_static_slice_table[1])
-/* ":status" */
-#define GRPC_MDSTR_STATUS (grpc_static_slice_table[2])
-/* ":authority" */
-#define GRPC_MDSTR_AUTHORITY (grpc_static_slice_table[3])
-/* ":scheme" */
-#define GRPC_MDSTR_SCHEME (grpc_static_slice_table[4])
-/* "te" */
-#define GRPC_MDSTR_TE (grpc_static_slice_table[5])
-/* "grpc-message" */
-#define GRPC_MDSTR_GRPC_MESSAGE (grpc_static_slice_table[6])
-/* "grpc-status" */
-#define GRPC_MDSTR_GRPC_STATUS (grpc_static_slice_table[7])
-/* "grpc-payload-bin" */
-#define GRPC_MDSTR_GRPC_PAYLOAD_BIN (grpc_static_slice_table[8])
-/* "grpc-encoding" */
-#define GRPC_MDSTR_GRPC_ENCODING (grpc_static_slice_table[9])
-/* "grpc-accept-encoding" */
-#define GRPC_MDSTR_GRPC_ACCEPT_ENCODING (grpc_static_slice_table[10])
-/* "content-type" */
-#define GRPC_MDSTR_CONTENT_TYPE (grpc_static_slice_table[11])
-/* "grpc-internal-encoding-request" */
-#define GRPC_MDSTR_GRPC_INTERNAL_ENCODING_REQUEST (grpc_static_slice_table[12])
-/* "user-agent" */
-#define GRPC_MDSTR_USER_AGENT (grpc_static_slice_table[13])
-/* "host" */
-#define GRPC_MDSTR_HOST (grpc_static_slice_table[14])
-/* "lb-token" */
-#define GRPC_MDSTR_LB_TOKEN (grpc_static_slice_table[15])
-/* "lb-cost-bin" */
-#define GRPC_MDSTR_LB_COST_BIN (grpc_static_slice_table[16])
-/* "grpc-timeout" */
-#define GRPC_MDSTR_GRPC_TIMEOUT (grpc_static_slice_table[17])
-/* "grpc-tracing-bin" */
-#define GRPC_MDSTR_GRPC_TRACING_BIN (grpc_static_slice_table[18])
-/* "grpc-stats-bin" */
-#define GRPC_MDSTR_GRPC_STATS_BIN (grpc_static_slice_table[19])
-/* "" */
-#define GRPC_MDSTR_EMPTY (grpc_static_slice_table[20])
-/* "grpc.wait_for_ready" */
-#define GRPC_MDSTR_GRPC_DOT_WAIT_FOR_READY (grpc_static_slice_table[21])
-/* "grpc.timeout" */
-#define GRPC_MDSTR_GRPC_DOT_TIMEOUT (grpc_static_slice_table[22])
-/* "grpc.max_request_message_bytes" */
-#define GRPC_MDSTR_GRPC_DOT_MAX_REQUEST_MESSAGE_BYTES \
-  (grpc_static_slice_table[23])
-/* "grpc.max_response_message_bytes" */
-#define GRPC_MDSTR_GRPC_DOT_MAX_RESPONSE_MESSAGE_BYTES \
-  (grpc_static_slice_table[24])
-/* "/grpc.lb.v1.LoadBalancer/BalanceLoad" */
-#define GRPC_MDSTR_SLASH_GRPC_DOT_LB_DOT_V1_DOT_LOADBALANCER_SLASH_BALANCELOAD \
-  (grpc_static_slice_table[25])
+#define GRPC_STATIC_MDSTR_COUNT 93
+extern grpc_mdstr grpc_static_mdstr_table[GRPC_STATIC_MDSTR_COUNT];
 /* "0" */
-#define GRPC_MDSTR_0 (grpc_static_slice_table[26])
+#define GRPC_MDSTR_0 (&grpc_static_mdstr_table[0])
 /* "1" */
-#define GRPC_MDSTR_1 (grpc_static_slice_table[27])
+#define GRPC_MDSTR_1 (&grpc_static_mdstr_table[1])
 /* "2" */
-#define GRPC_MDSTR_2 (grpc_static_slice_table[28])
-/* "identity" */
-#define GRPC_MDSTR_IDENTITY (grpc_static_slice_table[29])
-/* "gzip" */
-#define GRPC_MDSTR_GZIP (grpc_static_slice_table[30])
-/* "deflate" */
-#define GRPC_MDSTR_DEFLATE (grpc_static_slice_table[31])
-/* "trailers" */
-#define GRPC_MDSTR_TRAILERS (grpc_static_slice_table[32])
-/* "application/grpc" */
-#define GRPC_MDSTR_APPLICATION_SLASH_GRPC (grpc_static_slice_table[33])
-/* "POST" */
-#define GRPC_MDSTR_POST (grpc_static_slice_table[34])
+#define GRPC_MDSTR_2 (&grpc_static_mdstr_table[2])
 /* "200" */
-#define GRPC_MDSTR_200 (grpc_static_slice_table[35])
-/* "404" */
-#define GRPC_MDSTR_404 (grpc_static_slice_table[36])
-/* "http" */
-#define GRPC_MDSTR_HTTP (grpc_static_slice_table[37])
-/* "https" */
-#define GRPC_MDSTR_HTTPS (grpc_static_slice_table[38])
-/* "grpc" */
-#define GRPC_MDSTR_GRPC (grpc_static_slice_table[39])
-/* "GET" */
-#define GRPC_MDSTR_GET (grpc_static_slice_table[40])
-/* "PUT" */
-#define GRPC_MDSTR_PUT (grpc_static_slice_table[41])
-/* "/" */
-#define GRPC_MDSTR_SLASH (grpc_static_slice_table[42])
-/* "/index.html" */
-#define GRPC_MDSTR_SLASH_INDEX_DOT_HTML (grpc_static_slice_table[43])
+#define GRPC_MDSTR_200 (&grpc_static_mdstr_table[3])
 /* "204" */
-#define GRPC_MDSTR_204 (grpc_static_slice_table[44])
+#define GRPC_MDSTR_204 (&grpc_static_mdstr_table[4])
 /* "206" */
-#define GRPC_MDSTR_206 (grpc_static_slice_table[45])
+#define GRPC_MDSTR_206 (&grpc_static_mdstr_table[5])
 /* "304" */
-#define GRPC_MDSTR_304 (grpc_static_slice_table[46])
+#define GRPC_MDSTR_304 (&grpc_static_mdstr_table[6])
 /* "400" */
-#define GRPC_MDSTR_400 (grpc_static_slice_table[47])
+#define GRPC_MDSTR_400 (&grpc_static_mdstr_table[7])
+/* "404" */
+#define GRPC_MDSTR_404 (&grpc_static_mdstr_table[8])
 /* "500" */
-#define GRPC_MDSTR_500 (grpc_static_slice_table[48])
+#define GRPC_MDSTR_500 (&grpc_static_mdstr_table[9])
+/* "accept" */
+#define GRPC_MDSTR_ACCEPT (&grpc_static_mdstr_table[10])
 /* "accept-charset" */
-#define GRPC_MDSTR_ACCEPT_CHARSET (grpc_static_slice_table[49])
+#define GRPC_MDSTR_ACCEPT_CHARSET (&grpc_static_mdstr_table[11])
 /* "accept-encoding" */
-#define GRPC_MDSTR_ACCEPT_ENCODING (grpc_static_slice_table[50])
-/* "gzip, deflate" */
-#define GRPC_MDSTR_GZIP_COMMA_DEFLATE (grpc_static_slice_table[51])
+#define GRPC_MDSTR_ACCEPT_ENCODING (&grpc_static_mdstr_table[12])
 /* "accept-language" */
-#define GRPC_MDSTR_ACCEPT_LANGUAGE (grpc_static_slice_table[52])
+#define GRPC_MDSTR_ACCEPT_LANGUAGE (&grpc_static_mdstr_table[13])
 /* "accept-ranges" */
-#define GRPC_MDSTR_ACCEPT_RANGES (grpc_static_slice_table[53])
-/* "accept" */
-#define GRPC_MDSTR_ACCEPT (grpc_static_slice_table[54])
+#define GRPC_MDSTR_ACCEPT_RANGES (&grpc_static_mdstr_table[14])
 /* "access-control-allow-origin" */
-#define GRPC_MDSTR_ACCESS_CONTROL_ALLOW_ORIGIN (grpc_static_slice_table[55])
+#define GRPC_MDSTR_ACCESS_CONTROL_ALLOW_ORIGIN (&grpc_static_mdstr_table[15])
 /* "age" */
-#define GRPC_MDSTR_AGE (grpc_static_slice_table[56])
+#define GRPC_MDSTR_AGE (&grpc_static_mdstr_table[16])
 /* "allow" */
-#define GRPC_MDSTR_ALLOW (grpc_static_slice_table[57])
+#define GRPC_MDSTR_ALLOW (&grpc_static_mdstr_table[17])
+/* "application/grpc" */
+#define GRPC_MDSTR_APPLICATION_SLASH_GRPC (&grpc_static_mdstr_table[18])
+/* ":authority" */
+#define GRPC_MDSTR_AUTHORITY (&grpc_static_mdstr_table[19])
 /* "authorization" */
-#define GRPC_MDSTR_AUTHORIZATION (grpc_static_slice_table[58])
+#define GRPC_MDSTR_AUTHORIZATION (&grpc_static_mdstr_table[20])
 /* "cache-control" */
-#define GRPC_MDSTR_CACHE_CONTROL (grpc_static_slice_table[59])
+#define GRPC_MDSTR_CACHE_CONTROL (&grpc_static_mdstr_table[21])
 /* "content-disposition" */
-#define GRPC_MDSTR_CONTENT_DISPOSITION (grpc_static_slice_table[60])
+#define GRPC_MDSTR_CONTENT_DISPOSITION (&grpc_static_mdstr_table[22])
 /* "content-encoding" */
-#define GRPC_MDSTR_CONTENT_ENCODING (grpc_static_slice_table[61])
+#define GRPC_MDSTR_CONTENT_ENCODING (&grpc_static_mdstr_table[23])
 /* "content-language" */
-#define GRPC_MDSTR_CONTENT_LANGUAGE (grpc_static_slice_table[62])
+#define GRPC_MDSTR_CONTENT_LANGUAGE (&grpc_static_mdstr_table[24])
 /* "content-length" */
-#define GRPC_MDSTR_CONTENT_LENGTH (grpc_static_slice_table[63])
+#define GRPC_MDSTR_CONTENT_LENGTH (&grpc_static_mdstr_table[25])
 /* "content-location" */
-#define GRPC_MDSTR_CONTENT_LOCATION (grpc_static_slice_table[64])
+#define GRPC_MDSTR_CONTENT_LOCATION (&grpc_static_mdstr_table[26])
 /* "content-range" */
-#define GRPC_MDSTR_CONTENT_RANGE (grpc_static_slice_table[65])
+#define GRPC_MDSTR_CONTENT_RANGE (&grpc_static_mdstr_table[27])
+/* "content-type" */
+#define GRPC_MDSTR_CONTENT_TYPE (&grpc_static_mdstr_table[28])
 /* "cookie" */
-#define GRPC_MDSTR_COOKIE (grpc_static_slice_table[66])
+#define GRPC_MDSTR_COOKIE (&grpc_static_mdstr_table[29])
 /* "date" */
-#define GRPC_MDSTR_DATE (grpc_static_slice_table[67])
+#define GRPC_MDSTR_DATE (&grpc_static_mdstr_table[30])
+/* "deflate" */
+#define GRPC_MDSTR_DEFLATE (&grpc_static_mdstr_table[31])
+/* "deflate,gzip" */
+#define GRPC_MDSTR_DEFLATE_COMMA_GZIP (&grpc_static_mdstr_table[32])
+/* "" */
+#define GRPC_MDSTR_EMPTY (&grpc_static_mdstr_table[33])
 /* "etag" */
-#define GRPC_MDSTR_ETAG (grpc_static_slice_table[68])
+#define GRPC_MDSTR_ETAG (&grpc_static_mdstr_table[34])
 /* "expect" */
-#define GRPC_MDSTR_EXPECT (grpc_static_slice_table[69])
+#define GRPC_MDSTR_EXPECT (&grpc_static_mdstr_table[35])
 /* "expires" */
-#define GRPC_MDSTR_EXPIRES (grpc_static_slice_table[70])
+#define GRPC_MDSTR_EXPIRES (&grpc_static_mdstr_table[36])
 /* "from" */
-#define GRPC_MDSTR_FROM (grpc_static_slice_table[71])
+#define GRPC_MDSTR_FROM (&grpc_static_mdstr_table[37])
+/* "GET" */
+#define GRPC_MDSTR_GET (&grpc_static_mdstr_table[38])
+/* "grpc" */
+#define GRPC_MDSTR_GRPC (&grpc_static_mdstr_table[39])
+/* "grpc-accept-encoding" */
+#define GRPC_MDSTR_GRPC_ACCEPT_ENCODING (&grpc_static_mdstr_table[40])
+/* "grpc-encoding" */
+#define GRPC_MDSTR_GRPC_ENCODING (&grpc_static_mdstr_table[41])
+/* "grpc-internal-encoding-request" */
+#define GRPC_MDSTR_GRPC_INTERNAL_ENCODING_REQUEST (&grpc_static_mdstr_table[42])
+/* "grpc-message" */
+#define GRPC_MDSTR_GRPC_MESSAGE (&grpc_static_mdstr_table[43])
+/* "grpc-payload-bin" */
+#define GRPC_MDSTR_GRPC_PAYLOAD_BIN (&grpc_static_mdstr_table[44])
+/* "grpc-stats-bin" */
+#define GRPC_MDSTR_GRPC_STATS_BIN (&grpc_static_mdstr_table[45])
+/* "grpc-status" */
+#define GRPC_MDSTR_GRPC_STATUS (&grpc_static_mdstr_table[46])
+/* "grpc-timeout" */
+#define GRPC_MDSTR_GRPC_TIMEOUT (&grpc_static_mdstr_table[47])
+/* "grpc-tracing-bin" */
+#define GRPC_MDSTR_GRPC_TRACING_BIN (&grpc_static_mdstr_table[48])
+/* "gzip" */
+#define GRPC_MDSTR_GZIP (&grpc_static_mdstr_table[49])
+/* "gzip, deflate" */
+#define GRPC_MDSTR_GZIP_COMMA_DEFLATE (&grpc_static_mdstr_table[50])
+/* "host" */
+#define GRPC_MDSTR_HOST (&grpc_static_mdstr_table[51])
+/* "http" */
+#define GRPC_MDSTR_HTTP (&grpc_static_mdstr_table[52])
+/* "https" */
+#define GRPC_MDSTR_HTTPS (&grpc_static_mdstr_table[53])
+/* "identity" */
+#define GRPC_MDSTR_IDENTITY (&grpc_static_mdstr_table[54])
+/* "identity,deflate" */
+#define GRPC_MDSTR_IDENTITY_COMMA_DEFLATE (&grpc_static_mdstr_table[55])
+/* "identity,deflate,gzip" */
+#define GRPC_MDSTR_IDENTITY_COMMA_DEFLATE_COMMA_GZIP \
+  (&grpc_static_mdstr_table[56])
+/* "identity,gzip" */
+#define GRPC_MDSTR_IDENTITY_COMMA_GZIP (&grpc_static_mdstr_table[57])
 /* "if-match" */
-#define GRPC_MDSTR_IF_MATCH (grpc_static_slice_table[72])
+#define GRPC_MDSTR_IF_MATCH (&grpc_static_mdstr_table[58])
 /* "if-modified-since" */
-#define GRPC_MDSTR_IF_MODIFIED_SINCE (grpc_static_slice_table[73])
+#define GRPC_MDSTR_IF_MODIFIED_SINCE (&grpc_static_mdstr_table[59])
 /* "if-none-match" */
-#define GRPC_MDSTR_IF_NONE_MATCH (grpc_static_slice_table[74])
+#define GRPC_MDSTR_IF_NONE_MATCH (&grpc_static_mdstr_table[60])
 /* "if-range" */
-#define GRPC_MDSTR_IF_RANGE (grpc_static_slice_table[75])
+#define GRPC_MDSTR_IF_RANGE (&grpc_static_mdstr_table[61])
 /* "if-unmodified-since" */
-#define GRPC_MDSTR_IF_UNMODIFIED_SINCE (grpc_static_slice_table[76])
+#define GRPC_MDSTR_IF_UNMODIFIED_SINCE (&grpc_static_mdstr_table[62])
 /* "last-modified" */
-#define GRPC_MDSTR_LAST_MODIFIED (grpc_static_slice_table[77])
+#define GRPC_MDSTR_LAST_MODIFIED (&grpc_static_mdstr_table[63])
+/* "lb-cost-bin" */
+#define GRPC_MDSTR_LB_COST_BIN (&grpc_static_mdstr_table[64])
+/* "lb-token" */
+#define GRPC_MDSTR_LB_TOKEN (&grpc_static_mdstr_table[65])
 /* "link" */
-#define GRPC_MDSTR_LINK (grpc_static_slice_table[78])
+#define GRPC_MDSTR_LINK (&grpc_static_mdstr_table[66])
 /* "location" */
-#define GRPC_MDSTR_LOCATION (grpc_static_slice_table[79])
+#define GRPC_MDSTR_LOCATION (&grpc_static_mdstr_table[67])
 /* "max-forwards" */
-#define GRPC_MDSTR_MAX_FORWARDS (grpc_static_slice_table[80])
+#define GRPC_MDSTR_MAX_FORWARDS (&grpc_static_mdstr_table[68])
+/* ":method" */
+#define GRPC_MDSTR_METHOD (&grpc_static_mdstr_table[69])
+/* ":path" */
+#define GRPC_MDSTR_PATH (&grpc_static_mdstr_table[70])
+/* "POST" */
+#define GRPC_MDSTR_POST (&grpc_static_mdstr_table[71])
 /* "proxy-authenticate" */
-#define GRPC_MDSTR_PROXY_AUTHENTICATE (grpc_static_slice_table[81])
+#define GRPC_MDSTR_PROXY_AUTHENTICATE (&grpc_static_mdstr_table[72])
 /* "proxy-authorization" */
-#define GRPC_MDSTR_PROXY_AUTHORIZATION (grpc_static_slice_table[82])
+#define GRPC_MDSTR_PROXY_AUTHORIZATION (&grpc_static_mdstr_table[73])
+/* "PUT" */
+#define GRPC_MDSTR_PUT (&grpc_static_mdstr_table[74])
 /* "range" */
-#define GRPC_MDSTR_RANGE (grpc_static_slice_table[83])
+#define GRPC_MDSTR_RANGE (&grpc_static_mdstr_table[75])
 /* "referer" */
-#define GRPC_MDSTR_REFERER (grpc_static_slice_table[84])
+#define GRPC_MDSTR_REFERER (&grpc_static_mdstr_table[76])
 /* "refresh" */
-#define GRPC_MDSTR_REFRESH (grpc_static_slice_table[85])
+#define GRPC_MDSTR_REFRESH (&grpc_static_mdstr_table[77])
 /* "retry-after" */
-#define GRPC_MDSTR_RETRY_AFTER (grpc_static_slice_table[86])
+#define GRPC_MDSTR_RETRY_AFTER (&grpc_static_mdstr_table[78])
+/* ":scheme" */
+#define GRPC_MDSTR_SCHEME (&grpc_static_mdstr_table[79])
 /* "server" */
-#define GRPC_MDSTR_SERVER (grpc_static_slice_table[87])
+#define GRPC_MDSTR_SERVER (&grpc_static_mdstr_table[80])
 /* "set-cookie" */
-#define GRPC_MDSTR_SET_COOKIE (grpc_static_slice_table[88])
+#define GRPC_MDSTR_SET_COOKIE (&grpc_static_mdstr_table[81])
+/* "/" */
+#define GRPC_MDSTR_SLASH (&grpc_static_mdstr_table[82])
+/* "/index.html" */
+#define GRPC_MDSTR_SLASH_INDEX_DOT_HTML (&grpc_static_mdstr_table[83])
+/* ":status" */
+#define GRPC_MDSTR_STATUS (&grpc_static_mdstr_table[84])
 /* "strict-transport-security" */
-#define GRPC_MDSTR_STRICT_TRANSPORT_SECURITY (grpc_static_slice_table[89])
+#define GRPC_MDSTR_STRICT_TRANSPORT_SECURITY (&grpc_static_mdstr_table[85])
+/* "te" */
+#define GRPC_MDSTR_TE (&grpc_static_mdstr_table[86])
+/* "trailers" */
+#define GRPC_MDSTR_TRAILERS (&grpc_static_mdstr_table[87])
 /* "transfer-encoding" */
-#define GRPC_MDSTR_TRANSFER_ENCODING (grpc_static_slice_table[90])
+#define GRPC_MDSTR_TRANSFER_ENCODING (&grpc_static_mdstr_table[88])
+/* "user-agent" */
+#define GRPC_MDSTR_USER_AGENT (&grpc_static_mdstr_table[89])
 /* "vary" */
-#define GRPC_MDSTR_VARY (grpc_static_slice_table[91])
+#define GRPC_MDSTR_VARY (&grpc_static_mdstr_table[90])
 /* "via" */
-#define GRPC_MDSTR_VIA (grpc_static_slice_table[92])
+#define GRPC_MDSTR_VIA (&grpc_static_mdstr_table[91])
 /* "www-authenticate" */
-#define GRPC_MDSTR_WWW_AUTHENTICATE (grpc_static_slice_table[93])
-/* "identity,deflate" */
-#define GRPC_MDSTR_IDENTITY_COMMA_DEFLATE (grpc_static_slice_table[94])
-/* "identity,gzip" */
-#define GRPC_MDSTR_IDENTITY_COMMA_GZIP (grpc_static_slice_table[95])
-/* "deflate,gzip" */
-#define GRPC_MDSTR_DEFLATE_COMMA_GZIP (grpc_static_slice_table[96])
-/* "identity,deflate,gzip" */
-#define GRPC_MDSTR_IDENTITY_COMMA_DEFLATE_COMMA_GZIP \
-  (grpc_static_slice_table[97])
-
-extern const grpc_slice_refcount_vtable grpc_static_metadata_vtable;
-extern grpc_slice_refcount
-    grpc_static_metadata_refcounts[GRPC_STATIC_MDSTR_COUNT];
-#define GRPC_IS_STATIC_METADATA_STRING(slice) \
-  ((slice).refcount != NULL &&                \
-   (slice).refcount->vtable == &grpc_static_metadata_vtable)
-
-#define GRPC_STATIC_METADATA_INDEX(static_slice) \
-  ((int)((static_slice).refcount - grpc_static_metadata_refcounts))
+#define GRPC_MDSTR_WWW_AUTHENTICATE (&grpc_static_mdstr_table[92])
 
 #define GRPC_STATIC_MDELEM_COUNT 81
-extern grpc_mdelem_data grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT];
+extern grpc_mdelem grpc_static_mdelem_table[GRPC_STATIC_MDELEM_COUNT];
 extern uintptr_t grpc_static_mdelem_user_data[GRPC_STATIC_MDELEM_COUNT];
-/* "grpc-status": "0" */
-#define GRPC_MDELEM_GRPC_STATUS_0 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[0], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-status": "1" */
-#define GRPC_MDELEM_GRPC_STATUS_1 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[1], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-status": "2" */
-#define GRPC_MDELEM_GRPC_STATUS_2 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[2], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-encoding": "identity" */
-#define GRPC_MDELEM_GRPC_ENCODING_IDENTITY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[3], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-encoding": "gzip" */
-#define GRPC_MDELEM_GRPC_ENCODING_GZIP \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[4], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-encoding": "deflate" */
-#define GRPC_MDELEM_GRPC_ENCODING_DEFLATE \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[5], GRPC_MDELEM_STORAGE_STATIC))
-/* "te": "trailers" */
-#define GRPC_MDELEM_TE_TRAILERS \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[6], GRPC_MDELEM_STORAGE_STATIC))
-/* "content-type": "application/grpc" */
-#define GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[7], GRPC_MDELEM_STORAGE_STATIC))
-/* ":method": "POST" */
-#define GRPC_MDELEM_METHOD_POST \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[8], GRPC_MDELEM_STORAGE_STATIC))
-/* ":status": "200" */
-#define GRPC_MDELEM_STATUS_200 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[9], GRPC_MDELEM_STORAGE_STATIC))
-/* ":status": "404" */
-#define GRPC_MDELEM_STATUS_404 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[10], GRPC_MDELEM_STORAGE_STATIC))
-/* ":scheme": "http" */
-#define GRPC_MDELEM_SCHEME_HTTP \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[11], GRPC_MDELEM_STORAGE_STATIC))
-/* ":scheme": "https" */
-#define GRPC_MDELEM_SCHEME_HTTPS \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[12], GRPC_MDELEM_STORAGE_STATIC))
-/* ":scheme": "grpc" */
-#define GRPC_MDELEM_SCHEME_GRPC \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[13], GRPC_MDELEM_STORAGE_STATIC))
-/* ":authority": "" */
-#define GRPC_MDELEM_AUTHORITY_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[14], GRPC_MDELEM_STORAGE_STATIC))
-/* ":method": "GET" */
-#define GRPC_MDELEM_METHOD_GET \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[15], GRPC_MDELEM_STORAGE_STATIC))
-/* ":method": "PUT" */
-#define GRPC_MDELEM_METHOD_PUT \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[16], GRPC_MDELEM_STORAGE_STATIC))
-/* ":path": "/" */
-#define GRPC_MDELEM_PATH_SLASH \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[17], GRPC_MDELEM_STORAGE_STATIC))
-/* ":path": "/index.html" */
-#define GRPC_MDELEM_PATH_SLASH_INDEX_DOT_HTML \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[18], GRPC_MDELEM_STORAGE_STATIC))
-/* ":status": "204" */
-#define GRPC_MDELEM_STATUS_204 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[19], GRPC_MDELEM_STORAGE_STATIC))
-/* ":status": "206" */
-#define GRPC_MDELEM_STATUS_206 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[20], GRPC_MDELEM_STORAGE_STATIC))
-/* ":status": "304" */
-#define GRPC_MDELEM_STATUS_304 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[21], GRPC_MDELEM_STORAGE_STATIC))
-/* ":status": "400" */
-#define GRPC_MDELEM_STATUS_400 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[22], GRPC_MDELEM_STORAGE_STATIC))
-/* ":status": "500" */
-#define GRPC_MDELEM_STATUS_500 \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[23], GRPC_MDELEM_STORAGE_STATIC))
 /* "accept-charset": "" */
-#define GRPC_MDELEM_ACCEPT_CHARSET_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[24], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_ACCEPT_CHARSET_EMPTY (&grpc_static_mdelem_table[0])
+/* "accept": "" */
+#define GRPC_MDELEM_ACCEPT_EMPTY (&grpc_static_mdelem_table[1])
 /* "accept-encoding": "" */
-#define GRPC_MDELEM_ACCEPT_ENCODING_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[25], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_ACCEPT_ENCODING_EMPTY (&grpc_static_mdelem_table[2])
 /* "accept-encoding": "gzip, deflate" */
 #define GRPC_MDELEM_ACCEPT_ENCODING_GZIP_COMMA_DEFLATE \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[26], GRPC_MDELEM_STORAGE_STATIC))
+  (&grpc_static_mdelem_table[3])
 /* "accept-language": "" */
-#define GRPC_MDELEM_ACCEPT_LANGUAGE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[27], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_ACCEPT_LANGUAGE_EMPTY (&grpc_static_mdelem_table[4])
 /* "accept-ranges": "" */
-#define GRPC_MDELEM_ACCEPT_RANGES_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[28], GRPC_MDELEM_STORAGE_STATIC))
-/* "accept": "" */
-#define GRPC_MDELEM_ACCEPT_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[29], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_ACCEPT_RANGES_EMPTY (&grpc_static_mdelem_table[5])
 /* "access-control-allow-origin": "" */
 #define GRPC_MDELEM_ACCESS_CONTROL_ALLOW_ORIGIN_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[30], GRPC_MDELEM_STORAGE_STATIC))
+  (&grpc_static_mdelem_table[6])
 /* "age": "" */
-#define GRPC_MDELEM_AGE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[31], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_AGE_EMPTY (&grpc_static_mdelem_table[7])
 /* "allow": "" */
-#define GRPC_MDELEM_ALLOW_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[32], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_ALLOW_EMPTY (&grpc_static_mdelem_table[8])
+/* ":authority": "" */
+#define GRPC_MDELEM_AUTHORITY_EMPTY (&grpc_static_mdelem_table[9])
 /* "authorization": "" */
-#define GRPC_MDELEM_AUTHORIZATION_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[33], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_AUTHORIZATION_EMPTY (&grpc_static_mdelem_table[10])
 /* "cache-control": "" */
-#define GRPC_MDELEM_CACHE_CONTROL_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[34], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CACHE_CONTROL_EMPTY (&grpc_static_mdelem_table[11])
 /* "content-disposition": "" */
-#define GRPC_MDELEM_CONTENT_DISPOSITION_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[35], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CONTENT_DISPOSITION_EMPTY (&grpc_static_mdelem_table[12])
 /* "content-encoding": "" */
-#define GRPC_MDELEM_CONTENT_ENCODING_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[36], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CONTENT_ENCODING_EMPTY (&grpc_static_mdelem_table[13])
 /* "content-language": "" */
-#define GRPC_MDELEM_CONTENT_LANGUAGE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[37], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CONTENT_LANGUAGE_EMPTY (&grpc_static_mdelem_table[14])
 /* "content-length": "" */
-#define GRPC_MDELEM_CONTENT_LENGTH_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[38], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CONTENT_LENGTH_EMPTY (&grpc_static_mdelem_table[15])
 /* "content-location": "" */
-#define GRPC_MDELEM_CONTENT_LOCATION_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[39], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CONTENT_LOCATION_EMPTY (&grpc_static_mdelem_table[16])
 /* "content-range": "" */
-#define GRPC_MDELEM_CONTENT_RANGE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[40], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CONTENT_RANGE_EMPTY (&grpc_static_mdelem_table[17])
+/* "content-type": "application/grpc" */
+#define GRPC_MDELEM_CONTENT_TYPE_APPLICATION_SLASH_GRPC \
+  (&grpc_static_mdelem_table[18])
 /* "content-type": "" */
-#define GRPC_MDELEM_CONTENT_TYPE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[41], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_CONTENT_TYPE_EMPTY (&grpc_static_mdelem_table[19])
 /* "cookie": "" */
-#define GRPC_MDELEM_COOKIE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[42], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_COOKIE_EMPTY (&grpc_static_mdelem_table[20])
 /* "date": "" */
-#define GRPC_MDELEM_DATE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[43], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_DATE_EMPTY (&grpc_static_mdelem_table[21])
 /* "etag": "" */
-#define GRPC_MDELEM_ETAG_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[44], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_ETAG_EMPTY (&grpc_static_mdelem_table[22])
 /* "expect": "" */
-#define GRPC_MDELEM_EXPECT_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[45], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_EXPECT_EMPTY (&grpc_static_mdelem_table[23])
 /* "expires": "" */
-#define GRPC_MDELEM_EXPIRES_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[46], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_EXPIRES_EMPTY (&grpc_static_mdelem_table[24])
 /* "from": "" */
-#define GRPC_MDELEM_FROM_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[47], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_FROM_EMPTY (&grpc_static_mdelem_table[25])
+/* "grpc-accept-encoding": "deflate" */
+#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_DEFLATE (&grpc_static_mdelem_table[26])
+/* "grpc-accept-encoding": "deflate,gzip" */
+#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_DEFLATE_COMMA_GZIP \
+  (&grpc_static_mdelem_table[27])
+/* "grpc-accept-encoding": "gzip" */
+#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_GZIP (&grpc_static_mdelem_table[28])
+/* "grpc-accept-encoding": "identity" */
+#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY \
+  (&grpc_static_mdelem_table[29])
+/* "grpc-accept-encoding": "identity,deflate" */
+#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY_COMMA_DEFLATE \
+  (&grpc_static_mdelem_table[30])
+/* "grpc-accept-encoding": "identity,deflate,gzip" */
+#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY_COMMA_DEFLATE_COMMA_GZIP \
+  (&grpc_static_mdelem_table[31])
+/* "grpc-accept-encoding": "identity,gzip" */
+#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY_COMMA_GZIP \
+  (&grpc_static_mdelem_table[32])
+/* "grpc-encoding": "deflate" */
+#define GRPC_MDELEM_GRPC_ENCODING_DEFLATE (&grpc_static_mdelem_table[33])
+/* "grpc-encoding": "gzip" */
+#define GRPC_MDELEM_GRPC_ENCODING_GZIP (&grpc_static_mdelem_table[34])
+/* "grpc-encoding": "identity" */
+#define GRPC_MDELEM_GRPC_ENCODING_IDENTITY (&grpc_static_mdelem_table[35])
+/* "grpc-status": "0" */
+#define GRPC_MDELEM_GRPC_STATUS_0 (&grpc_static_mdelem_table[36])
+/* "grpc-status": "1" */
+#define GRPC_MDELEM_GRPC_STATUS_1 (&grpc_static_mdelem_table[37])
+/* "grpc-status": "2" */
+#define GRPC_MDELEM_GRPC_STATUS_2 (&grpc_static_mdelem_table[38])
 /* "host": "" */
-#define GRPC_MDELEM_HOST_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[48], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_HOST_EMPTY (&grpc_static_mdelem_table[39])
 /* "if-match": "" */
-#define GRPC_MDELEM_IF_MATCH_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[49], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_IF_MATCH_EMPTY (&grpc_static_mdelem_table[40])
 /* "if-modified-since": "" */
-#define GRPC_MDELEM_IF_MODIFIED_SINCE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[50], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_IF_MODIFIED_SINCE_EMPTY (&grpc_static_mdelem_table[41])
 /* "if-none-match": "" */
-#define GRPC_MDELEM_IF_NONE_MATCH_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[51], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_IF_NONE_MATCH_EMPTY (&grpc_static_mdelem_table[42])
 /* "if-range": "" */
-#define GRPC_MDELEM_IF_RANGE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[52], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_IF_RANGE_EMPTY (&grpc_static_mdelem_table[43])
 /* "if-unmodified-since": "" */
-#define GRPC_MDELEM_IF_UNMODIFIED_SINCE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[53], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_IF_UNMODIFIED_SINCE_EMPTY (&grpc_static_mdelem_table[44])
 /* "last-modified": "" */
-#define GRPC_MDELEM_LAST_MODIFIED_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[54], GRPC_MDELEM_STORAGE_STATIC))
-/* "lb-token": "" */
-#define GRPC_MDELEM_LB_TOKEN_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[55], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_LAST_MODIFIED_EMPTY (&grpc_static_mdelem_table[45])
 /* "lb-cost-bin": "" */
-#define GRPC_MDELEM_LB_COST_BIN_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[56], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_LB_COST_BIN_EMPTY (&grpc_static_mdelem_table[46])
+/* "lb-token": "" */
+#define GRPC_MDELEM_LB_TOKEN_EMPTY (&grpc_static_mdelem_table[47])
 /* "link": "" */
-#define GRPC_MDELEM_LINK_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[57], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_LINK_EMPTY (&grpc_static_mdelem_table[48])
 /* "location": "" */
-#define GRPC_MDELEM_LOCATION_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[58], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_LOCATION_EMPTY (&grpc_static_mdelem_table[49])
 /* "max-forwards": "" */
-#define GRPC_MDELEM_MAX_FORWARDS_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[59], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_MAX_FORWARDS_EMPTY (&grpc_static_mdelem_table[50])
+/* ":method": "GET" */
+#define GRPC_MDELEM_METHOD_GET (&grpc_static_mdelem_table[51])
+/* ":method": "POST" */
+#define GRPC_MDELEM_METHOD_POST (&grpc_static_mdelem_table[52])
+/* ":method": "PUT" */
+#define GRPC_MDELEM_METHOD_PUT (&grpc_static_mdelem_table[53])
+/* ":path": "/" */
+#define GRPC_MDELEM_PATH_SLASH (&grpc_static_mdelem_table[54])
+/* ":path": "/index.html" */
+#define GRPC_MDELEM_PATH_SLASH_INDEX_DOT_HTML (&grpc_static_mdelem_table[55])
 /* "proxy-authenticate": "" */
-#define GRPC_MDELEM_PROXY_AUTHENTICATE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[60], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_PROXY_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[56])
 /* "proxy-authorization": "" */
-#define GRPC_MDELEM_PROXY_AUTHORIZATION_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[61], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_PROXY_AUTHORIZATION_EMPTY (&grpc_static_mdelem_table[57])
 /* "range": "" */
-#define GRPC_MDELEM_RANGE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[62], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_RANGE_EMPTY (&grpc_static_mdelem_table[58])
 /* "referer": "" */
-#define GRPC_MDELEM_REFERER_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[63], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_REFERER_EMPTY (&grpc_static_mdelem_table[59])
 /* "refresh": "" */
-#define GRPC_MDELEM_REFRESH_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[64], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_REFRESH_EMPTY (&grpc_static_mdelem_table[60])
 /* "retry-after": "" */
-#define GRPC_MDELEM_RETRY_AFTER_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[65], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_RETRY_AFTER_EMPTY (&grpc_static_mdelem_table[61])
+/* ":scheme": "grpc" */
+#define GRPC_MDELEM_SCHEME_GRPC (&grpc_static_mdelem_table[62])
+/* ":scheme": "http" */
+#define GRPC_MDELEM_SCHEME_HTTP (&grpc_static_mdelem_table[63])
+/* ":scheme": "https" */
+#define GRPC_MDELEM_SCHEME_HTTPS (&grpc_static_mdelem_table[64])
 /* "server": "" */
-#define GRPC_MDELEM_SERVER_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[66], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_SERVER_EMPTY (&grpc_static_mdelem_table[65])
 /* "set-cookie": "" */
-#define GRPC_MDELEM_SET_COOKIE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[67], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_SET_COOKIE_EMPTY (&grpc_static_mdelem_table[66])
+/* ":status": "200" */
+#define GRPC_MDELEM_STATUS_200 (&grpc_static_mdelem_table[67])
+/* ":status": "204" */
+#define GRPC_MDELEM_STATUS_204 (&grpc_static_mdelem_table[68])
+/* ":status": "206" */
+#define GRPC_MDELEM_STATUS_206 (&grpc_static_mdelem_table[69])
+/* ":status": "304" */
+#define GRPC_MDELEM_STATUS_304 (&grpc_static_mdelem_table[70])
+/* ":status": "400" */
+#define GRPC_MDELEM_STATUS_400 (&grpc_static_mdelem_table[71])
+/* ":status": "404" */
+#define GRPC_MDELEM_STATUS_404 (&grpc_static_mdelem_table[72])
+/* ":status": "500" */
+#define GRPC_MDELEM_STATUS_500 (&grpc_static_mdelem_table[73])
 /* "strict-transport-security": "" */
 #define GRPC_MDELEM_STRICT_TRANSPORT_SECURITY_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[68], GRPC_MDELEM_STORAGE_STATIC))
+  (&grpc_static_mdelem_table[74])
+/* "te": "trailers" */
+#define GRPC_MDELEM_TE_TRAILERS (&grpc_static_mdelem_table[75])
 /* "transfer-encoding": "" */
-#define GRPC_MDELEM_TRANSFER_ENCODING_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[69], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_TRANSFER_ENCODING_EMPTY (&grpc_static_mdelem_table[76])
 /* "user-agent": "" */
-#define GRPC_MDELEM_USER_AGENT_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[70], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_USER_AGENT_EMPTY (&grpc_static_mdelem_table[77])
 /* "vary": "" */
-#define GRPC_MDELEM_VARY_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[71], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_VARY_EMPTY (&grpc_static_mdelem_table[78])
 /* "via": "" */
-#define GRPC_MDELEM_VIA_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[72], GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_VIA_EMPTY (&grpc_static_mdelem_table[79])
 /* "www-authenticate": "" */
-#define GRPC_MDELEM_WWW_AUTHENTICATE_EMPTY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[73], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-accept-encoding": "identity" */
-#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[74], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-accept-encoding": "deflate" */
-#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_DEFLATE \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[75], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-accept-encoding": "identity,deflate" */
-#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY_COMMA_DEFLATE \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[76], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-accept-encoding": "gzip" */
-#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_GZIP \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[77], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-accept-encoding": "identity,gzip" */
-#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY_COMMA_GZIP \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[78], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-accept-encoding": "deflate,gzip" */
-#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_DEFLATE_COMMA_GZIP \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[79], GRPC_MDELEM_STORAGE_STATIC))
-/* "grpc-accept-encoding": "identity,deflate,gzip" */
-#define GRPC_MDELEM_GRPC_ACCEPT_ENCODING_IDENTITY_COMMA_DEFLATE_COMMA_GZIP \
-  (GRPC_MAKE_MDELEM(&grpc_static_mdelem_table[80], GRPC_MDELEM_STORAGE_STATIC))
-
-grpc_mdelem grpc_static_mdelem_for_static_strings(int a, int b);
-typedef enum {
-  GRPC_BATCH_PATH,
-  GRPC_BATCH_METHOD,
-  GRPC_BATCH_STATUS,
-  GRPC_BATCH_AUTHORITY,
-  GRPC_BATCH_SCHEME,
-  GRPC_BATCH_TE,
-  GRPC_BATCH_GRPC_MESSAGE,
-  GRPC_BATCH_GRPC_STATUS,
-  GRPC_BATCH_GRPC_PAYLOAD_BIN,
-  GRPC_BATCH_GRPC_ENCODING,
-  GRPC_BATCH_GRPC_ACCEPT_ENCODING,
-  GRPC_BATCH_CONTENT_TYPE,
-  GRPC_BATCH_GRPC_INTERNAL_ENCODING_REQUEST,
-  GRPC_BATCH_USER_AGENT,
-  GRPC_BATCH_HOST,
-  GRPC_BATCH_LB_TOKEN,
-  GRPC_BATCH_LB_COST_BIN,
-  GRPC_BATCH_CALLOUTS_COUNT
-} grpc_metadata_batch_callouts_index;
-
-typedef union {
-  struct grpc_linked_mdelem *array[GRPC_BATCH_CALLOUTS_COUNT];
-  struct {
-    struct grpc_linked_mdelem *path;
-    struct grpc_linked_mdelem *method;
-    struct grpc_linked_mdelem *status;
-    struct grpc_linked_mdelem *authority;
-    struct grpc_linked_mdelem *scheme;
-    struct grpc_linked_mdelem *te;
-    struct grpc_linked_mdelem *grpc_message;
-    struct grpc_linked_mdelem *grpc_status;
-    struct grpc_linked_mdelem *grpc_payload_bin;
-    struct grpc_linked_mdelem *grpc_encoding;
-    struct grpc_linked_mdelem *grpc_accept_encoding;
-    struct grpc_linked_mdelem *content_type;
-    struct grpc_linked_mdelem *grpc_internal_encoding_request;
-    struct grpc_linked_mdelem *user_agent;
-    struct grpc_linked_mdelem *host;
-    struct grpc_linked_mdelem *lb_token;
-    struct grpc_linked_mdelem *lb_cost_bin;
-  } named;
-} grpc_metadata_batch_callouts;
-
-#define GRPC_BATCH_INDEX_OF(slice)                      \
-  (GRPC_IS_STATIC_METADATA_STRING((slice))              \
-       ? (grpc_metadata_batch_callouts_index)GPR_CLAMP( \
-             GRPC_STATIC_METADATA_INDEX((slice)), 0,    \
-             GRPC_BATCH_CALLOUTS_COUNT)                 \
-       : GRPC_BATCH_CALLOUTS_COUNT)
+#define GRPC_MDELEM_WWW_AUTHENTICATE_EMPTY (&grpc_static_mdelem_table[80])
 
+extern const uint8_t
+    grpc_static_metadata_elem_indices[GRPC_STATIC_MDELEM_COUNT * 2];
+extern const char *const grpc_static_metadata_strings[GRPC_STATIC_MDSTR_COUNT];
 extern const uint8_t grpc_static_accept_encoding_metadata[8];
-#define GRPC_MDELEM_ACCEPT_ENCODING_FOR_ALGORITHMS(algs)                       \
-  (GRPC_MAKE_MDELEM(                                                           \
-      &grpc_static_mdelem_table[grpc_static_accept_encoding_metadata[(algs)]], \
-      GRPC_MDELEM_STORAGE_STATIC))
+#define GRPC_MDELEM_ACCEPT_ENCODING_FOR_ALGORITHMS(algs) \
+  (&grpc_static_mdelem_table[grpc_static_accept_encoding_metadata[(algs)]])
 #endif /* GRPC_CORE_LIB_TRANSPORT_STATIC_METADATA_H */
diff --git a/src/core/lib/transport/status_conversion.c b/src/core/lib/transport/status_conversion.c
deleted file mode 100644
index af0ac89db7..0000000000
--- a/src/core/lib/transport/status_conversion.c
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include "src/core/lib/transport/status_conversion.h"
-
-int grpc_status_to_http2_error(grpc_status_code status) {
-  switch (status) {
-    case GRPC_STATUS_OK:
-      return GRPC_HTTP2_NO_ERROR;
-    case GRPC_STATUS_CANCELLED:
-      return GRPC_HTTP2_CANCEL;
-    case GRPC_STATUS_DEADLINE_EXCEEDED:
-      return GRPC_HTTP2_CANCEL;
-    case GRPC_STATUS_RESOURCE_EXHAUSTED:
-      return GRPC_HTTP2_ENHANCE_YOUR_CALM;
-    case GRPC_STATUS_PERMISSION_DENIED:
-      return GRPC_HTTP2_INADEQUATE_SECURITY;
-    case GRPC_STATUS_UNAVAILABLE:
-      return GRPC_HTTP2_REFUSED_STREAM;
-    default:
-      return GRPC_HTTP2_INTERNAL_ERROR;
-  }
-}
-
-grpc_status_code grpc_http2_error_to_grpc_status(grpc_http2_error_code error,
-                                                 gpr_timespec deadline) {
-  switch (error) {
-    case GRPC_HTTP2_NO_ERROR:
-      /* should never be received */
-      return GRPC_STATUS_INTERNAL;
-    case GRPC_HTTP2_CANCEL:
-      /* http2 cancel translates to STATUS_CANCELLED iff deadline hasn't been
-       * exceeded */
-      return gpr_time_cmp(gpr_now(deadline.clock_type), deadline) >= 0
-                 ? GRPC_STATUS_DEADLINE_EXCEEDED
-                 : GRPC_STATUS_CANCELLED;
-    case GRPC_HTTP2_ENHANCE_YOUR_CALM:
-      return GRPC_STATUS_RESOURCE_EXHAUSTED;
-    case GRPC_HTTP2_INADEQUATE_SECURITY:
-      return GRPC_STATUS_PERMISSION_DENIED;
-    case GRPC_HTTP2_REFUSED_STREAM:
-      return GRPC_STATUS_UNAVAILABLE;
-    default:
-      return GRPC_STATUS_INTERNAL;
-  }
-}
-
-grpc_status_code grpc_http2_status_to_grpc_status(int status) {
-  switch (status) {
-    /* these HTTP2 status codes are called out explicitly in status.proto */
-    case 200:
-      return GRPC_STATUS_OK;
-    case 400:
-      return GRPC_STATUS_INVALID_ARGUMENT;
-    case 401:
-      return GRPC_STATUS_UNAUTHENTICATED;
-    case 403:
-      return GRPC_STATUS_PERMISSION_DENIED;
-    case 404:
-      return GRPC_STATUS_NOT_FOUND;
-    case 409:
-      return GRPC_STATUS_ABORTED;
-    case 412:
-      return GRPC_STATUS_FAILED_PRECONDITION;
-    case 429:
-      return GRPC_STATUS_RESOURCE_EXHAUSTED;
-    case 499:
-      return GRPC_STATUS_CANCELLED;
-    case 500:
-      return GRPC_STATUS_UNKNOWN;
-    case 501:
-      return GRPC_STATUS_UNIMPLEMENTED;
-    case 503:
-      return GRPC_STATUS_UNAVAILABLE;
-    case 504:
-      return GRPC_STATUS_DEADLINE_EXCEEDED;
-    /* everything else is unknown */
-    default:
-      return GRPC_STATUS_UNKNOWN;
-  }
-}
-
-int grpc_status_to_http2_status(grpc_status_code status) { return 200; }
diff --git a/src/core/lib/transport/status_conversion.h b/src/core/lib/transport/status_conversion.h
deleted file mode 100644
index e6a23a606b..0000000000
--- a/src/core/lib/transport/status_conversion.h
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- *
- * Copyright 2015, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#ifndef GRPC_CORE_LIB_TRANSPORT_STATUS_CONVERSION_H
-#define GRPC_CORE_LIB_TRANSPORT_STATUS_CONVERSION_H
-
-#include <grpc/grpc.h>
-#include "src/core/lib/transport/http2_errors.h"
-
-/* Conversion of grpc status codes to http2 error codes (for RST_STREAM) */
-grpc_http2_error_code grpc_status_to_http2_error(grpc_status_code status);
-grpc_status_code grpc_http2_error_to_grpc_status(grpc_http2_error_code error,
-                                                 gpr_timespec deadline);
-
-/* Conversion of HTTP status codes (:status) to grpc status codes */
-grpc_status_code grpc_http2_status_to_grpc_status(int status);
-int grpc_status_to_http2_status(grpc_status_code status);
-
-#endif /* GRPC_CORE_LIB_TRANSPORT_STATUS_CONVERSION_H */
diff --git a/src/core/lib/transport/timeout_encoding.c b/src/core/lib/transport/timeout_encoding.c
index 0d4d7e5a7e..b58ebbd0a8 100644
--- a/src/core/lib/transport/timeout_encoding.c
+++ b/src/core/lib/transport/timeout_encoding.c
@@ -131,21 +131,20 @@ void grpc_http2_encode_timeout(gpr_timespec timeout, char *buffer) {
   }
 }
 
-static int is_all_whitespace(const char *p, const char *end) {
-  while (p != end && *p == ' ') p++;
-  return p == end;
+static int is_all_whitespace(const char *p) {
+  while (*p == ' ') p++;
+  return *p == 0;
 }
 
-int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout) {
+int grpc_http2_decode_timeout(const char *buffer, gpr_timespec *timeout) {
   int32_t x = 0;
-  const uint8_t *p = GRPC_SLICE_START_PTR(text);
-  const uint8_t *end = GRPC_SLICE_END_PTR(text);
+  const uint8_t *p = (const uint8_t *)buffer;
   int have_digit = 0;
   /* skip whitespace */
-  for (; p != end && *p == ' '; p++)
+  for (; *p == ' '; p++)
     ;
   /* decode numeric part */
-  for (; p != end && *p >= '0' && *p <= '9'; p++) {
+  for (; *p >= '0' && *p <= '9'; p++) {
     int32_t digit = (int32_t)(*p - (uint8_t)'0');
     have_digit = 1;
     /* spec allows max. 8 digits, but we allow values up to 1,000,000,000 */
@@ -159,9 +158,8 @@ int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout) {
   }
   if (!have_digit) return 0;
   /* skip whitespace */
-  for (; p != end && *p == ' '; p++)
+  for (; *p == ' '; p++)
     ;
-  if (p == end) return 0;
   /* decode unit specifier */
   switch (*p) {
     case 'n':
@@ -186,5 +184,5 @@ int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout) {
       return 0;
   }
   p++;
-  return is_all_whitespace((const char *)p, (const char *)end);
+  return is_all_whitespace((const char *)p);
 }
diff --git a/src/core/lib/transport/timeout_encoding.h b/src/core/lib/transport/timeout_encoding.h
index 4c8025d800..92f02f6ecd 100644
--- a/src/core/lib/transport/timeout_encoding.h
+++ b/src/core/lib/transport/timeout_encoding.h
@@ -34,9 +34,7 @@
 #ifndef GRPC_CORE_LIB_TRANSPORT_TIMEOUT_ENCODING_H
 #define GRPC_CORE_LIB_TRANSPORT_TIMEOUT_ENCODING_H
 
-#include <grpc/slice.h>
 #include <grpc/support/time.h>
-
 #include "src/core/lib/support/string.h"
 
 #define GRPC_HTTP2_TIMEOUT_ENCODE_MIN_BUFSIZE (GPR_LTOA_MIN_BUFSIZE + 1)
@@ -44,6 +42,6 @@
 /* Encode/decode timeouts to the GRPC over HTTP/2 format;
    encoding may round up arbitrarily */
 void grpc_http2_encode_timeout(gpr_timespec timeout, char *buffer);
-int grpc_http2_decode_timeout(grpc_slice text, gpr_timespec *timeout);
+int grpc_http2_decode_timeout(const char *buffer, gpr_timespec *timeout);
 
 #endif /* GRPC_CORE_LIB_TRANSPORT_TIMEOUT_ENCODING_H */
diff --git a/src/core/lib/transport/transport.c b/src/core/lib/transport/transport.c
index 004e748f25..055edbb39f 100644
--- a/src/core/lib/transport/transport.c
+++ b/src/core/lib/transport/transport.c
@@ -40,7 +40,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 
-#include "src/core/lib/iomgr/executor.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_string_helpers.h"
 #include "src/core/lib/support/string.h"
@@ -70,16 +69,6 @@ void grpc_stream_unref(grpc_exec_ctx *exec_ctx,
                        grpc_stream_refcount *refcount) {
 #endif
   if (gpr_unref(&refcount->refs)) {
-    if (exec_ctx->flags & GRPC_EXEC_CTX_FLAG_THREAD_RESOURCE_LOOP) {
-      /* Ick.
-         The thread we're running on MAY be owned (indirectly) by a call-stack.
-         If that's the case, destroying the call-stack MAY try to destroy the
-         thread, which is a tangled mess that we just don't want to ever have to
-         cope with.
-         Throw this over to the executor (on a core-owned thread) and process it
-         there. */
-      refcount->destroy.scheduler = grpc_executor_scheduler;
-    }
     grpc_closure_sched(exec_ctx, &refcount->destroy, GRPC_ERROR_NONE);
   }
 }
@@ -184,7 +173,93 @@ void grpc_transport_stream_op_finish_with_failure(grpc_exec_ctx *exec_ctx,
   grpc_closure_sched(exec_ctx, op->recv_initial_metadata_ready,
                      GRPC_ERROR_REF(error));
   grpc_closure_sched(exec_ctx, op->on_complete, error);
-  GRPC_ERROR_UNREF(op->cancel_error);
+}
+
+typedef struct {
+  grpc_error *error;
+  grpc_closure *then_call;
+  grpc_closure closure;
+} close_message_data;
+
+static void free_message(grpc_exec_ctx *exec_ctx, void *p, grpc_error *error) {
+  close_message_data *cmd = p;
+  GRPC_ERROR_UNREF(cmd->error);
+  if (cmd->then_call != NULL) {
+    cmd->then_call->cb(exec_ctx, cmd->then_call->cb_arg, error);
+  }
+  gpr_free(cmd);
+}
+
+static void add_error(grpc_transport_stream_op *op, grpc_error **which,
+                      grpc_error *error) {
+  close_message_data *cmd;
+  cmd = gpr_malloc(sizeof(*cmd));
+  cmd->error = error;
+  cmd->then_call = op->on_complete;
+  grpc_closure_init(&cmd->closure, free_message, cmd,
+                    grpc_schedule_on_exec_ctx);
+  op->on_complete = &cmd->closure;
+  *which = error;
+}
+
+void grpc_transport_stream_op_add_cancellation(grpc_transport_stream_op *op,
+                                               grpc_status_code status) {
+  GPR_ASSERT(status != GRPC_STATUS_OK);
+  if (op->cancel_error == GRPC_ERROR_NONE) {
+    op->cancel_error = grpc_error_set_int(GRPC_ERROR_CANCELLED,
+                                          GRPC_ERROR_INT_GRPC_STATUS, status);
+    op->close_error = GRPC_ERROR_NONE;
+  }
+}
+
+void grpc_transport_stream_op_add_cancellation_with_message(
+    grpc_exec_ctx *exec_ctx, grpc_transport_stream_op *op,
+    grpc_status_code status, grpc_slice *optional_message) {
+  GPR_ASSERT(status != GRPC_STATUS_OK);
+  if (op->cancel_error != GRPC_ERROR_NONE) {
+    if (optional_message) {
+      grpc_slice_unref_internal(exec_ctx, *optional_message);
+    }
+    return;
+  }
+  grpc_error *error;
+  if (optional_message != NULL) {
+    char *msg = grpc_dump_slice(*optional_message, GPR_DUMP_ASCII);
+    error = grpc_error_set_str(GRPC_ERROR_CREATE(msg),
+                               GRPC_ERROR_STR_GRPC_MESSAGE, msg);
+    gpr_free(msg);
+    grpc_slice_unref_internal(exec_ctx, *optional_message);
+  } else {
+    error = GRPC_ERROR_CREATE("Call cancelled");
+  }
+  error = grpc_error_set_int(error, GRPC_ERROR_INT_GRPC_STATUS, status);
+  add_error(op, &op->cancel_error, error);
+}
+
+void grpc_transport_stream_op_add_close(grpc_exec_ctx *exec_ctx,
+                                        grpc_transport_stream_op *op,
+                                        grpc_status_code status,
+                                        grpc_slice *optional_message) {
+  GPR_ASSERT(status != GRPC_STATUS_OK);
+  if (op->cancel_error != GRPC_ERROR_NONE ||
+      op->close_error != GRPC_ERROR_NONE) {
+    if (optional_message) {
+      grpc_slice_unref_internal(exec_ctx, *optional_message);
+    }
+    return;
+  }
+  grpc_error *error;
+  if (optional_message != NULL) {
+    char *msg = grpc_dump_slice(*optional_message, GPR_DUMP_ASCII);
+    error = grpc_error_set_str(GRPC_ERROR_CREATE(msg),
+                               GRPC_ERROR_STR_GRPC_MESSAGE, msg);
+    gpr_free(msg);
+    grpc_slice_unref_internal(exec_ctx, *optional_message);
+  } else {
+    error = GRPC_ERROR_CREATE("Call force closed");
+  }
+  error = grpc_error_set_int(error, GRPC_ERROR_INT_GRPC_STATUS, status);
+  add_error(op, &op->close_error, error);
 }
 
 typedef struct {
diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index 9a0abe1ca4..d1281830aa 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -150,18 +150,13 @@ typedef struct grpc_transport_stream_op {
   /** Collect any stats into provided buffer, zero internal stat counters */
   grpc_transport_stream_stats *collect_stats;
 
-  /** If != GRPC_ERROR_NONE, forcefully close this stream.
-      The HTTP2 semantics should be:
-      - server side: if cancel_error has GRPC_ERROR_INT_GRPC_STATUS, and
-        trailing metadata has not been sent, send trailing metadata with status
-        and message from cancel_error (use grpc_error_get_status) followed by
-        a RST_STREAM with error=GRPC_CHTTP2_NO_ERROR to force a full close
-      - at all other times: use grpc_error_get_status to get a status code, and
-        convert to a HTTP2 error code using
-        grpc_chttp2_grpc_status_to_http2_error. Send a RST_STREAM with this
-        error. */
+  /** If != GRPC_ERROR_NONE, cancel this stream */
   grpc_error *cancel_error;
 
+  /** If != GRPC_ERROR_NONE, send grpc-status, grpc-message, and close this
+      stream for both reading and writing */
+  grpc_error *close_error;
+
   /* Indexes correspond to grpc_context_index enum values */
   grpc_call_context_element *context;
 
@@ -181,8 +176,13 @@ typedef struct grpc_transport_op {
   grpc_connectivity_state *connectivity_state;
   /** should the transport be disconnected */
   grpc_error *disconnect_with_error;
+  /** should we send a goaway?
+      after a goaway is sent, once there are no more active calls on
+      the transport, the transport should disconnect */
+  bool send_goaway;
   /** what should the goaway contain? */
-  grpc_error *goaway_error;
+  grpc_status_code goaway_status;
+  grpc_slice *goaway_message;
   /** set the callback for accepting new streams;
       this is a permanent callback, unlike the other one-shot closures.
       If true, the callback is set to set_accept_stream_fn, with its
@@ -245,6 +245,18 @@ void grpc_transport_stream_op_finish_with_failure(grpc_exec_ctx *exec_ctx,
                                                   grpc_transport_stream_op *op,
                                                   grpc_error *error);
 
+void grpc_transport_stream_op_add_cancellation(grpc_transport_stream_op *op,
+                                               grpc_status_code status);
+
+void grpc_transport_stream_op_add_cancellation_with_message(
+    grpc_exec_ctx *exec_ctx, grpc_transport_stream_op *op,
+    grpc_status_code status, grpc_slice *optional_message);
+
+void grpc_transport_stream_op_add_close(grpc_exec_ctx *exec_ctx,
+                                        grpc_transport_stream_op *op,
+                                        grpc_status_code status,
+                                        grpc_slice *optional_message);
+
 char *grpc_transport_stream_op_string(grpc_transport_stream_op *op);
 char *grpc_transport_op_string(grpc_transport_op *op);
 
diff --git a/src/core/lib/transport/transport_op_string.c b/src/core/lib/transport/transport_op_string.c
index 28360e3784..58d6ad508e 100644
--- a/src/core/lib/transport/transport_op_string.c
+++ b/src/core/lib/transport/transport_op_string.c
@@ -47,14 +47,14 @@
 /* These routines are here to facilitate debugging - they produce string
    representations of various transport data structures */
 
-static void put_metadata(gpr_strvec *b, grpc_mdelem md) {
+static void put_metadata(gpr_strvec *b, grpc_mdelem *md) {
   gpr_strvec_add(b, gpr_strdup("key="));
   gpr_strvec_add(
-      b, grpc_dump_slice(GRPC_MDKEY(md), GPR_DUMP_HEX | GPR_DUMP_ASCII));
+      b, grpc_dump_slice(md->key->slice, GPR_DUMP_HEX | GPR_DUMP_ASCII));
 
   gpr_strvec_add(b, gpr_strdup(" value="));
   gpr_strvec_add(
-      b, grpc_dump_slice(GRPC_MDVALUE(md), GPR_DUMP_HEX | GPR_DUMP_ASCII));
+      b, grpc_dump_slice(md->value->slice, GPR_DUMP_HEX | GPR_DUMP_ASCII));
 }
 
 static void put_metadata_list(gpr_strvec *b, grpc_metadata_batch md) {
@@ -121,7 +121,15 @@ char *grpc_transport_stream_op_string(grpc_transport_stream_op *op) {
     gpr_strvec_add(&b, gpr_strdup(" "));
     const char *msg = grpc_error_string(op->cancel_error);
     gpr_asprintf(&tmp, "CANCEL:%s", msg);
+    grpc_error_free_string(msg);
+    gpr_strvec_add(&b, tmp);
+  }
 
+  if (op->close_error != GRPC_ERROR_NONE) {
+    gpr_strvec_add(&b, gpr_strdup(" "));
+    const char *msg = grpc_error_string(op->close_error);
+    gpr_asprintf(&tmp, "CLOSE:%s", msg);
+    grpc_error_free_string(msg);
     gpr_strvec_add(&b, tmp);
   }
 
@@ -160,14 +168,18 @@ char *grpc_transport_op_string(grpc_transport_op *op) {
     const char *err = grpc_error_string(op->disconnect_with_error);
     gpr_asprintf(&tmp, "DISCONNECT:%s", err);
     gpr_strvec_add(&b, tmp);
+    grpc_error_free_string(err);
   }
 
-  if (op->goaway_error) {
+  if (op->send_goaway) {
     if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
     first = false;
-    const char *msg = grpc_error_string(op->goaway_error);
-    gpr_asprintf(&tmp, "SEND_GOAWAY:%s", msg);
-
+    char *msg = op->goaway_message == NULL
+                    ? "null"
+                    : grpc_dump_slice(*op->goaway_message,
+                                      GPR_DUMP_ASCII | GPR_DUMP_HEX);
+    gpr_asprintf(&tmp, "SEND_GOAWAY:status=%d:msg=%s", op->goaway_status, msg);
+    if (op->goaway_message != NULL) gpr_free(msg);
     gpr_strvec_add(&b, tmp);
   }