Merge pull request #4342 from grpc/release-0_12

Merge release-0_12 into master

41 files changed, 950 insertions, 2658 deletions

diff --git a/src/python/grpcio/grpc/_adapter/_c/module.c b/src/python/grpcio/grpc/_adapter/_c/module.c
deleted file mode 100644
index 9b93b051f6..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/module.c
+++ /dev/null
@@ -1,67 +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 <stdlib.h>
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-
-#include "grpc/_adapter/_c/types.h"
-
-static PyMethodDef c_methods[] = {
-    {NULL}
-};
-
-PyMODINIT_FUNC init_c(void) {
-  PyObject *module;
-
-  module = Py_InitModule3("_c", c_methods,
-                          "Wrappings of C structures and functions.");
-
-  if (pygrpc_module_add_types(module) < 0) {
-    return;
-  }
-
-  if (PyModule_AddStringConstant(
-          module, "PRIMARY_USER_AGENT_KEY",
-          GRPC_ARG_PRIMARY_USER_AGENT_STRING) < 0) {
-    return;
-  }
-
-  /* GRPC maintains an internal counter of how many times it has been
-     initialized and handles multiple pairs of grpc_init()/grpc_shutdown()
-     invocations accordingly. */
-  grpc_init();
-  atexit(&grpc_shutdown);
-}
diff --git a/src/python/grpcio/grpc/_adapter/_c/types.c b/src/python/grpcio/grpc/_adapter/_c/types.c
deleted file mode 100644
index 8dedf5902b..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types.c
+++ /dev/null
@@ -1,61 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-
-int pygrpc_module_add_types(PyObject *module) {
-  int i;
-  PyTypeObject *types[] = {
-      &pygrpc_CallCredentials_type,
-      &pygrpc_ChannelCredentials_type,
-      &pygrpc_ServerCredentials_type,
-      &pygrpc_CompletionQueue_type,
-      &pygrpc_Call_type,
-      &pygrpc_Channel_type,
-      &pygrpc_Server_type
-  };
-  for (i = 0; i < sizeof(types)/sizeof(PyTypeObject *); ++i) {
-    if (PyType_Ready(types[i]) < 0) {
-      return -1;
-    }
-  }
-  for (i = 0; i < sizeof(types)/sizeof(PyTypeObject *); ++i) {
-    Py_INCREF(types[i]);
-    PyModule_AddObject(module, types[i]->tp_name, (PyObject *)types[i]);
-  }
-  return 0;
-}
diff --git a/src/python/grpcio/grpc/_adapter/_c/types.h b/src/python/grpcio/grpc/_adapter/_c/types.h
deleted file mode 100644
index 9ab415d216..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types.h
+++ /dev/null
@@ -1,286 +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__ADAPTER__C_TYPES_H_
-#define GRPC__ADAPTER__C_TYPES_H_
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-#include <grpc/grpc_security.h>
-
-
-/*=========================*/
-/* Client-side credentials */
-/*=========================*/
-
-typedef struct ChannelCredentials {
-  PyObject_HEAD
-  grpc_channel_credentials *c_creds;
-} ChannelCredentials;
-void pygrpc_ChannelCredentials_dealloc(ChannelCredentials *self);
-ChannelCredentials *pygrpc_ChannelCredentials_google_default(
-    PyTypeObject *type, PyObject *ignored);
-ChannelCredentials *pygrpc_ChannelCredentials_ssl(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-ChannelCredentials *pygrpc_ChannelCredentials_composite(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-extern PyTypeObject pygrpc_ChannelCredentials_type;
-
-typedef struct CallCredentials {
-  PyObject_HEAD
-  grpc_call_credentials *c_creds;
-} CallCredentials;
-void pygrpc_CallCredentials_dealloc(CallCredentials *self);
-CallCredentials *pygrpc_CallCredentials_composite(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-CallCredentials *pygrpc_CallCredentials_compute_engine(
-    PyTypeObject *type, PyObject *ignored);
-CallCredentials *pygrpc_CallCredentials_jwt(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-CallCredentials *pygrpc_CallCredentials_refresh_token(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-CallCredentials *pygrpc_CallCredentials_iam(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-extern PyTypeObject pygrpc_CallCredentials_type;
-
-/*=========================*/
-/* Server-side credentials */
-/*=========================*/
-
-typedef struct ServerCredentials {
-  PyObject_HEAD
-  grpc_server_credentials *c_creds;
-} ServerCredentials;
-void pygrpc_ServerCredentials_dealloc(ServerCredentials *self);
-ServerCredentials *pygrpc_ServerCredentials_ssl(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-extern PyTypeObject pygrpc_ServerCredentials_type;
-
-
-/*==================*/
-/* Completion queue */
-/*==================*/
-
-typedef struct CompletionQueue {
-  PyObject_HEAD
-  grpc_completion_queue *c_cq;
-} CompletionQueue;
-CompletionQueue *pygrpc_CompletionQueue_new(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-void pygrpc_CompletionQueue_dealloc(CompletionQueue *self);
-PyObject *pygrpc_CompletionQueue_next(
-    CompletionQueue *self, PyObject *args, PyObject *kwargs);
-PyObject *pygrpc_CompletionQueue_shutdown(
-    CompletionQueue *self, PyObject *ignored);
-extern PyTypeObject pygrpc_CompletionQueue_type;
-
-
-/*======*/
-/* Call */
-/*======*/
-
-typedef struct Call {
-  PyObject_HEAD
-  grpc_call *c_call;
-  CompletionQueue *cq;
-} Call;
-Call *pygrpc_Call_new_empty(CompletionQueue *cq);
-void pygrpc_Call_dealloc(Call *self);
-PyObject *pygrpc_Call_start_batch(Call *self, PyObject *args, PyObject *kwargs);
-PyObject *pygrpc_Call_cancel(Call *self, PyObject *args, PyObject *kwargs);
-PyObject *pygrpc_Call_peer(Call *self);
-PyObject *pygrpc_Call_set_credentials(Call *self, PyObject *args,
-                                      PyObject *kwargs);
-extern PyTypeObject pygrpc_Call_type;
-
-
-/*=========*/
-/* Channel */
-/*=========*/
-
-typedef struct Channel {
-  PyObject_HEAD
-  grpc_channel *c_chan;
-} Channel;
-Channel *pygrpc_Channel_new(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs);
-void pygrpc_Channel_dealloc(Channel *self);
-Call *pygrpc_Channel_create_call(
-    Channel *self, PyObject *args, PyObject *kwargs);
-PyObject *pygrpc_Channel_check_connectivity_state(Channel *self, PyObject *args,
-                                                  PyObject *kwargs);
-PyObject *pygrpc_Channel_watch_connectivity_state(Channel *self, PyObject *args,
-                                                  PyObject *kwargs);
-PyObject *pygrpc_Channel_target(Channel *self);
-extern PyTypeObject pygrpc_Channel_type;
-
-
-/*========*/
-/* Server */
-/*========*/
-
-typedef struct Server {
-  PyObject_HEAD
-  grpc_server *c_serv;
-  CompletionQueue *cq;
-  int shutdown_called;
-} Server;
-Server *pygrpc_Server_new(PyTypeObject *type, PyObject *args, PyObject *kwargs);
-void pygrpc_Server_dealloc(Server *self);
-PyObject *pygrpc_Server_request_call(
-    Server *self, PyObject *args, PyObject *kwargs);
-PyObject *pygrpc_Server_add_http2_port(
-    Server *self, PyObject *args, PyObject *kwargs);
-PyObject *pygrpc_Server_start(Server *self, PyObject *ignored);
-PyObject *pygrpc_Server_shutdown(
-    Server *self, PyObject *args, PyObject *kwargs);
-PyObject *pygrpc_Server_cancel_all_calls(Server *self, PyObject *unused);
-extern PyTypeObject pygrpc_Server_type;
-
-/*=========*/
-/* Utility */
-/*=========*/
-
-/* Every tag that passes from Python GRPC to GRPC core is of this type. */
-typedef struct pygrpc_tag {
-  PyObject *user_tag;
-  Call *call;
-  grpc_call_details request_call_details;
-  grpc_metadata_array request_metadata;
-  grpc_op *ops;
-  size_t nops;
-  int is_new_call;
-} pygrpc_tag;
-
-/* Construct a tag associated with a batch call. Does not take ownership of the
-   resources in the elements of ops. */
-pygrpc_tag *pygrpc_produce_batch_tag(PyObject *user_tag, Call *call,
-                                     grpc_op *ops, size_t nops);
-
-
-/* Construct a tag associated with a server request. The calling code should
-   use the appropriate fields of the produced tag in the invocation of
-   grpc_server_request_call. */
-pygrpc_tag *pygrpc_produce_request_tag(PyObject *user_tag, Call *empty_call);
-
-/* Construct a tag associated with a server shutdown. */
-pygrpc_tag *pygrpc_produce_server_shutdown_tag(PyObject *user_tag);
-
-/* Construct a tag associated with a channel state change. */
-pygrpc_tag *pygrpc_produce_channel_state_change_tag(PyObject *user_tag);
-
-/* Frees all resources owned by the tag and the tag itself. */
-void pygrpc_discard_tag(pygrpc_tag *tag);
-
-/* Consumes an event and its associated tag, providing a Python tuple of the
-   form `(type, tag, call, call_details, results)` (where type is an integer
-   corresponding to a grpc_completion_type, tag is an arbitrary PyObject, call
-   is the call object associated with the event [if any], call_details is a
-   tuple of form `(method, host, deadline)` [if such details are available],
-   and resultd is a list of tuples of form `(type, metadata, message, status,
-   cancelled)` [where type corresponds to a grpc_op_type, metadata is a
-   sequence of 2-sequences of strings, message is a byte string, and status is
-   a 2-tuple of an integer corresponding to grpc_status_code and a string of
-   status details]).
-
-   Frees all resources associated with the event tag. */
-PyObject *pygrpc_consume_event(grpc_event event);
-
-/* Transliterate the Python tuple of form `(type, metadata, message,
-   status)` (where type is an integer corresponding to a grpc_op_type, metadata
-   is a sequence of 2-sequences of strings, message is a byte string, and
-   status is 2-tuple of an integer corresponding to grpc_status_code and a
-   string of status details) to a grpc_op suitable for use in a
-   grpc_call_start_batch invocation. The grpc_op is a 'directory' of resources
-   that must be freed after GRPC core is done with them.
-
-   Calls gpr_malloc (or the appropriate type-specific grpc_*_create function)
-   to populate the appropriate union-discriminated members of the op.
-
-   Returns true on success, false on failure. */
-int pygrpc_produce_op(PyObject *op, grpc_op *result);
-
-/* Discards all resources associated with the passed in op that was produced by
-   pygrpc_produce_op. */
-void pygrpc_discard_op(grpc_op op);
-
-/* Transliterate the grpc_ops (which have been sent through a
-   grpc_call_start_batch invocation and whose corresponding event has appeared
-   on a completion queue) to a Python tuple of form `(type, metadata, message,
-   status, cancelled)` (where type is an integer corresponding to a
-   grpc_op_type, metadata is a sequence of 2-sequences of strings, message is a
-   byte string, and status is 2-tuple of an integer corresponding to
-   grpc_status_code and a string of status details).
-
-   Calls gpr_free (or the appropriate type-specific grpc_*_destroy function) on
-   the appropriate union-discriminated populated members of the ops. */
-PyObject *pygrpc_consume_ops(grpc_op *op, size_t nops);
-
-/* Transliterate from a gpr_timespec to a double (in units of seconds, either
-   from the epoch if interpreted absolutely or as a delta otherwise). */
-double pygrpc_cast_gpr_timespec_to_double(gpr_timespec timespec);
-
-/* Transliterate from a double (in units of seconds from the epoch if
-   interpreted absolutely or as a delta otherwise) to a gpr_timespec. */
-gpr_timespec pygrpc_cast_double_to_gpr_timespec(double seconds);
-
-/* Returns true on success, false on failure. */
-int pygrpc_cast_pyseq_to_send_metadata(
-    PyObject *pyseq, grpc_metadata **metadata, size_t *count);
-/* Returns a metadata array as a Python object on success, else NULL. */
-PyObject *pygrpc_cast_metadata_array_to_pyseq(grpc_metadata_array metadata);
-
-/* Transliterate from a list of python channel arguments (2-tuples of string
-   and string|integer|None) to a grpc_channel_args object. The strings placed
-   in the grpc_channel_args object's grpc_arg elements are views of the Python
-   object. The Python object must live long enough for the grpc_channel_args
-   to be used. Arguments set to None are silently ignored. Returns true on
-   success, false on failure. */
-int pygrpc_produce_channel_args(PyObject *py_args, grpc_channel_args *c_args);
-void pygrpc_discard_channel_args(grpc_channel_args args);
-
-/* Read the bytes from grpc_byte_buffer to a gpr_malloc'd array of bytes;
-   output to result and result_size. */
-void pygrpc_byte_buffer_to_bytes(
-    grpc_byte_buffer *buffer, char **result, size_t *result_size);
-
-
-/*========*/
-/* Module */
-/*========*/
-
-/* Returns 0 on success, -1 on failure. */
-int pygrpc_module_add_types(PyObject *module);
-
-#endif  /* GRPC__ADAPTER__C_TYPES_H_ */
diff --git a/src/python/grpcio/grpc/_adapter/_c/types/call.c b/src/python/grpcio/grpc/_adapter/_c/types/call.c
deleted file mode 100644
index 04ec871880..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types/call.c
+++ /dev/null
@@ -1,186 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-#include <grpc/support/alloc.h>
-
-
-PyMethodDef pygrpc_Call_methods[] = {
-    {"start_batch", (PyCFunction)pygrpc_Call_start_batch, METH_KEYWORDS, ""},
-    {"cancel", (PyCFunction)pygrpc_Call_cancel, METH_KEYWORDS, ""},
-    {"peer", (PyCFunction)pygrpc_Call_peer, METH_NOARGS, ""},
-    {"set_credentials", (PyCFunction)pygrpc_Call_set_credentials, METH_KEYWORDS,
-     ""},
-    {NULL}
-};
-const char pygrpc_Call_doc[] = "See grpc._adapter._types.Call.";
-PyTypeObject pygrpc_Call_type = {
-    PyObject_HEAD_INIT(NULL)
-    0,                                        /* ob_size */
-    "Call",                                   /* tp_name */
-    sizeof(Call),                             /* tp_basicsize */
-    0,                                        /* tp_itemsize */
-    (destructor)pygrpc_Call_dealloc,          /* tp_dealloc */
-    0,                                        /* tp_print */
-    0,                                        /* tp_getattr */
-    0,                                        /* tp_setattr */
-    0,                                        /* tp_compare */
-    0,                                        /* tp_repr */
-    0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
-    0,                                        /* tp_as_mapping */
-    0,                                        /* tp_hash */
-    0,                                        /* tp_call */
-    0,                                        /* tp_str */
-    0,                                        /* tp_getattro */
-    0,                                        /* tp_setattro */
-    0,                                        /* tp_as_buffer */
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
-    pygrpc_Call_doc,                          /* tp_doc */
-    0,                                        /* tp_traverse */
-    0,                                        /* tp_clear */
-    0,                                        /* tp_richcompare */
-    0,                                        /* tp_weaklistoffset */
-    0,                                        /* tp_iter */
-    0,                                        /* tp_iternext */
-    pygrpc_Call_methods,                      /* tp_methods */
-    0,                                        /* tp_members */
-    0,                                        /* tp_getset */
-    0,                                        /* tp_base */
-    0,                                        /* tp_dict */
-    0,                                        /* tp_descr_get */
-    0,                                        /* tp_descr_set */
-    0,                                        /* tp_dictoffset */
-    0,                                        /* tp_init */
-    0,                                        /* tp_alloc */
-    0                                         /* tp_new */
-};
-
-Call *pygrpc_Call_new_empty(CompletionQueue *cq) {
-  Call *call = (Call *)pygrpc_Call_type.tp_alloc(&pygrpc_Call_type, 0);
-  call->c_call = NULL;
-  call->cq = cq;
-  Py_XINCREF(call->cq);
-  return call;
-}
-void pygrpc_Call_dealloc(Call *self) {
-  if (self->c_call) {
-    grpc_call_destroy(self->c_call);
-  }
-  Py_XDECREF(self->cq);
-  self->ob_type->tp_free((PyObject *)self);
-}
-PyObject *pygrpc_Call_start_batch(Call *self, PyObject *args, PyObject *kwargs) {
-  PyObject *op_list;
-  PyObject *user_tag;
-  grpc_op *ops;
-  size_t nops;
-  size_t i;
-  size_t j;
-  pygrpc_tag *tag;
-  grpc_call_error errcode;
-  static char *keywords[] = {"ops", "tag", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "OO:start_batch", keywords,
-                                   &op_list, &user_tag)) {
-    return NULL;
-  }
-  if (!PyList_Check(op_list)) {
-    PyErr_SetString(PyExc_TypeError, "expected a list of OpArgs");
-    return NULL;
-  }
-  nops = PyList_Size(op_list);
-  ops = gpr_malloc(sizeof(grpc_op) * nops);
-  for (i = 0; i < nops; ++i) {
-    PyObject *item = PyList_GET_ITEM(op_list, i);
-    if (!pygrpc_produce_op(item, &ops[i])) {
-      for (j = 0; j < i; ++j) {
-        pygrpc_discard_op(ops[j]);
-      }
-      return NULL;
-    }
-  }
-  tag = pygrpc_produce_batch_tag(user_tag, self, ops, nops);
-  errcode = grpc_call_start_batch(self->c_call, tag->ops, tag->nops, tag, NULL);
-  gpr_free(ops);
-  return PyInt_FromLong(errcode);
-}
-PyObject *pygrpc_Call_cancel(Call *self, PyObject *args, PyObject *kwargs) {
-  PyObject *py_code = NULL;
-  grpc_call_error errcode;
-  int code;
-  char *details = NULL;
-  static char *keywords[] = {"code", "details", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|Os:start_batch", keywords,
-                                   &py_code, &details)) {
-    return NULL;
-  }
-  if (py_code != NULL && details != NULL) {
-    if (!PyInt_Check(py_code)) {
-      PyErr_SetString(PyExc_TypeError, "expected integer code");
-      return NULL;
-    }
-    code = PyInt_AsLong(py_code);
-    errcode = grpc_call_cancel_with_status(self->c_call, code, details, NULL);
-  } else if (py_code != NULL || details != NULL) {
-    PyErr_SetString(PyExc_ValueError,
-                    "if `code` is specified, so must `details`");
-    return NULL;
-  } else {
-    errcode = grpc_call_cancel(self->c_call, NULL);
-  }
-  return PyInt_FromLong(errcode);
-}
-
-PyObject *pygrpc_Call_peer(Call *self) {
-  char *peer = grpc_call_get_peer(self->c_call);
-  PyObject *py_peer = PyString_FromString(peer);
-  gpr_free(peer);
-  return py_peer;
-}
-PyObject *pygrpc_Call_set_credentials(Call *self, PyObject *args,
-                                      PyObject *kwargs) {
-  CallCredentials *creds;
-  grpc_call_error errcode;
-  static char *keywords[] = {"creds", NULL};
-  if (!PyArg_ParseTupleAndKeywords(
-      args, kwargs, "O!:set_credentials", keywords,
-      &pygrpc_CallCredentials_type, &creds)) {
-    return NULL;
-  }
-  errcode = grpc_call_set_credentials(self->c_call, creds->c_creds);
-  return PyInt_FromLong(errcode);
-}
diff --git a/src/python/grpcio/grpc/_adapter/_c/types/call_credentials.c b/src/python/grpcio/grpc/_adapter/_c/types/call_credentials.c
deleted file mode 100644
index 5a15a6e17d..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types/call_credentials.c
+++ /dev/null
@@ -1,203 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-#include <grpc/grpc_security.h>
-
-
-PyMethodDef pygrpc_CallCredentials_methods[] = {
-    {"composite", (PyCFunction)pygrpc_CallCredentials_composite,
-     METH_CLASS|METH_KEYWORDS, ""},
-    {"compute_engine", (PyCFunction)pygrpc_CallCredentials_compute_engine,
-     METH_CLASS|METH_NOARGS, ""},
-    {"jwt", (PyCFunction)pygrpc_CallCredentials_jwt,
-     METH_CLASS|METH_KEYWORDS, ""},
-    {"refresh_token", (PyCFunction)pygrpc_CallCredentials_refresh_token,
-     METH_CLASS|METH_KEYWORDS, ""},
-    {"iam", (PyCFunction)pygrpc_CallCredentials_iam,
-     METH_CLASS|METH_KEYWORDS, ""},
-    {NULL}
-};
-
-const char pygrpc_CallCredentials_doc[] = "";
-PyTypeObject pygrpc_CallCredentials_type = {
-    PyObject_HEAD_INIT(NULL)
-    0,                                        /* ob_size */
-    "CallCredentials",                        /* tp_name */
-    sizeof(CallCredentials),                  /* tp_basicsize */
-    0,                                        /* tp_itemsize */
-    (destructor)pygrpc_CallCredentials_dealloc, /* tp_dealloc */
-    0,                                        /* tp_print */
-    0,                                        /* tp_getattr */
-    0,                                        /* tp_setattr */
-    0,                                        /* tp_compare */
-    0,                                        /* tp_repr */
-    0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
-    0,                                        /* tp_as_mapping */
-    0,                                        /* tp_hash */
-    0,                                        /* tp_call */
-    0,                                        /* tp_str */
-    0,                                        /* tp_getattro */
-    0,                                        /* tp_setattro */
-    0,                                        /* tp_as_buffer */
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
-    pygrpc_CallCredentials_doc,             /* tp_doc */
-    0,                                        /* tp_traverse */
-    0,                                        /* tp_clear */
-    0,                                        /* tp_richcompare */
-    0,                                        /* tp_weaklistoffset */
-    0,                                        /* tp_iter */
-    0,                                        /* tp_iternext */
-    pygrpc_CallCredentials_methods,         /* tp_methods */
-    0,                                        /* tp_members */
-    0,                                        /* tp_getset */
-    0,                                        /* tp_base */
-    0,                                        /* tp_dict */
-    0,                                        /* tp_descr_get */
-    0,                                        /* tp_descr_set */
-    0,                                        /* tp_dictoffset */
-    0,                                        /* tp_init */
-    0,                                        /* tp_alloc */
-    0                                         /* tp_new */
-};
-
-void pygrpc_CallCredentials_dealloc(CallCredentials *self) {
-  grpc_call_credentials_release(self->c_creds);
-  self->ob_type->tp_free((PyObject *)self);
-}
-
-CallCredentials *pygrpc_CallCredentials_composite(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  CallCredentials *self;
-  CallCredentials *creds1;
-  CallCredentials *creds2;
-  static char *keywords[] = {"creds1", "creds2", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O!O!:composite", keywords,
-        &pygrpc_CallCredentials_type, &creds1,
-        &pygrpc_CallCredentials_type, &creds2)) {
-    return NULL;
-  }
-  self = (CallCredentials *)type->tp_alloc(type, 0);
-  self->c_creds =
-      grpc_composite_call_credentials_create(
-          creds1->c_creds, creds2->c_creds, NULL);
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(PyExc_RuntimeError, "couldn't create composite credentials");
-    return NULL;
-  }
-  return self;
-}
-
-CallCredentials *pygrpc_CallCredentials_compute_engine(
-    PyTypeObject *type, PyObject *ignored) {
-  CallCredentials *self = (CallCredentials *)type->tp_alloc(type, 0);
-  self->c_creds = grpc_google_compute_engine_credentials_create(NULL);
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(PyExc_RuntimeError,
-                    "couldn't create compute engine credentials");
-    return NULL;
-  }
-  return self;
-}
-
-/* TODO: Rename this credentials to something like service_account_jwt_access */
-CallCredentials *pygrpc_CallCredentials_jwt(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  CallCredentials *self;
-  const char *json_key;
-  double lifetime;
-  static char *keywords[] = {"json_key", "token_lifetime", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "sd:jwt", keywords,
-        &json_key, &lifetime)) {
-    return NULL;
-  }
-  self = (CallCredentials *)type->tp_alloc(type, 0);
-  self->c_creds = grpc_service_account_jwt_access_credentials_create(
-      json_key, pygrpc_cast_double_to_gpr_timespec(lifetime), NULL);
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(PyExc_RuntimeError, "couldn't create JWT credentials");
-    return NULL;
-  }
-  return self;
-}
-
-CallCredentials *pygrpc_CallCredentials_refresh_token(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  CallCredentials *self;
-  const char *json_refresh_token;
-  static char *keywords[] = {"json_refresh_token", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s:refresh_token", keywords,
-        &json_refresh_token)) {
-    return NULL;
-  }
-  self = (CallCredentials *)type->tp_alloc(type, 0);
-  self->c_creds =
-      grpc_google_refresh_token_credentials_create(json_refresh_token, NULL);
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(PyExc_RuntimeError,
-                    "couldn't create credentials from refresh token");
-    return NULL;
-  }
-  return self;
-}
-
-CallCredentials *pygrpc_CallCredentials_iam(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  CallCredentials *self;
-  const char *authorization_token;
-  const char *authority_selector;
-  static char *keywords[] = {"authorization_token", "authority_selector", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "ss:iam", keywords,
-        &authorization_token, &authority_selector)) {
-    return NULL;
-  }
-  self = (CallCredentials *)type->tp_alloc(type, 0);
-  self->c_creds = grpc_google_iam_credentials_create(authorization_token,
-                                                     authority_selector, NULL);
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(PyExc_RuntimeError, "couldn't create IAM credentials");
-    return NULL;
-  }
-  return self;
-}
-
diff --git a/src/python/grpcio/grpc/_adapter/_c/types/channel.c b/src/python/grpcio/grpc/_adapter/_c/types/channel.c
deleted file mode 100644
index c4db2a0dfd..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types/channel.c
+++ /dev/null
@@ -1,187 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-#include <grpc/support/alloc.h>
-
-
-PyMethodDef pygrpc_Channel_methods[] = {
-    {"create_call", (PyCFunction)pygrpc_Channel_create_call, METH_KEYWORDS, ""},
-    {"check_connectivity_state", (PyCFunction)pygrpc_Channel_check_connectivity_state, METH_KEYWORDS, ""},
-    {"watch_connectivity_state", (PyCFunction)pygrpc_Channel_watch_connectivity_state, METH_KEYWORDS, ""},
-    {"target", (PyCFunction)pygrpc_Channel_target, METH_NOARGS, ""},
-    {NULL}
-};
-const char pygrpc_Channel_doc[] = "See grpc._adapter._types.Channel.";
-PyTypeObject pygrpc_Channel_type = {
-    PyObject_HEAD_INIT(NULL)
-    0,                                        /* ob_size */
-    "Channel",                                /* tp_name */
-    sizeof(Channel),                          /* tp_basicsize */
-    0,                                        /* tp_itemsize */
-    (destructor)pygrpc_Channel_dealloc,       /* tp_dealloc */
-    0,                                        /* tp_print */
-    0,                                        /* tp_getattr */
-    0,                                        /* tp_setattr */
-    0,                                        /* tp_compare */
-    0,                                        /* tp_repr */
-    0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
-    0,                                        /* tp_as_mapping */
-    0,                                        /* tp_hash */
-    0,                                        /* tp_call */
-    0,                                        /* tp_str */
-    0,                                        /* tp_getattro */
-    0,                                        /* tp_setattro */
-    0,                                        /* tp_as_buffer */
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
-    pygrpc_Channel_doc,                       /* tp_doc */
-    0,                                        /* tp_traverse */
-    0,                                        /* tp_clear */
-    0,                                        /* tp_richcompare */
-    0,                                        /* tp_weaklistoffset */
-    0,                                        /* tp_iter */
-    0,                                        /* tp_iternext */
-    pygrpc_Channel_methods,                   /* tp_methods */
-    0,                                        /* tp_members */
-    0,                                        /* tp_getset */
-    0,                                        /* tp_base */
-    0,                                        /* tp_dict */
-    0,                                        /* tp_descr_get */
-    0,                                        /* tp_descr_set */
-    0,                                        /* tp_dictoffset */
-    0,                                        /* tp_init */
-    0,                                        /* tp_alloc */
-    (newfunc)pygrpc_Channel_new               /* tp_new */
-};
-
-Channel *pygrpc_Channel_new(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  Channel *self;
-  const char *target;
-  PyObject *py_args;
-  ChannelCredentials *creds = NULL;
-  grpc_channel_args c_args;
-  char *keywords[] = {"target", "args", "creds", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "sO|O!:Channel", keywords,
-        &target, &py_args, &pygrpc_ChannelCredentials_type, &creds)) {
-    return NULL;
-  }
-  if (!pygrpc_produce_channel_args(py_args, &c_args)) {
-    return NULL;
-  }
-  self = (Channel *)type->tp_alloc(type, 0);
-  if (creds) {
-    self->c_chan =
-        grpc_secure_channel_create(creds->c_creds, target, &c_args, NULL);
-  } else {
-    self->c_chan = grpc_insecure_channel_create(target, &c_args, NULL);
-  }
-  pygrpc_discard_channel_args(c_args);
-  return self;
-}
-void pygrpc_Channel_dealloc(Channel *self) {
-  grpc_channel_destroy(self->c_chan);
-  self->ob_type->tp_free((PyObject *)self);
-}
-
-Call *pygrpc_Channel_create_call(
-    Channel *self, PyObject *args, PyObject *kwargs) {
-  Call *call;
-  CompletionQueue *cq;
-  const char *method;
-  const char *host;
-  double deadline;
-  char *keywords[] = {"cq", "method", "host", "deadline", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O!szd:create_call", keywords,
-        &pygrpc_CompletionQueue_type, &cq, &method, &host, &deadline)) {
-    return NULL;
-  }
-  call = pygrpc_Call_new_empty(cq);
-  call->c_call = grpc_channel_create_call(
-      self->c_chan, NULL, GRPC_PROPAGATE_DEFAULTS, cq->c_cq, method, host,
-      pygrpc_cast_double_to_gpr_timespec(deadline), NULL);
-  return call;
-}
-
-PyObject *pygrpc_Channel_check_connectivity_state(
-    Channel *self, PyObject *args, PyObject *kwargs) {
-  PyObject *py_try_to_connect;
-  int try_to_connect;
-  char *keywords[] = {"try_to_connect", NULL};
-  grpc_connectivity_state state;
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O:connectivity_state", keywords,
-                                   &py_try_to_connect)) {
-    return NULL;
-  }
-  if (!PyBool_Check(py_try_to_connect)) {
-    Py_XDECREF(py_try_to_connect);
-    return NULL;
-  }
-  try_to_connect = Py_True == py_try_to_connect;
-  Py_DECREF(py_try_to_connect);
-  state = grpc_channel_check_connectivity_state(self->c_chan, try_to_connect);
-  return PyInt_FromLong(state);
-}
-
-PyObject *pygrpc_Channel_watch_connectivity_state(
-    Channel *self, PyObject *args, PyObject *kwargs) {
-  PyObject *tag;
-  double deadline;
-  int last_observed_state;
-  CompletionQueue *completion_queue;
-  char *keywords[] = {"last_observed_state", "deadline",
-                      "completion_queue", "tag", NULL};
-  if (!PyArg_ParseTupleAndKeywords(
-      args, kwargs, "idO!O:watch_connectivity_state", keywords,
-      &last_observed_state, &deadline, &pygrpc_CompletionQueue_type,
-      &completion_queue, &tag)) {
-    return NULL;
-  }
-  grpc_channel_watch_connectivity_state(
-      self->c_chan, (grpc_connectivity_state)last_observed_state,
-      pygrpc_cast_double_to_gpr_timespec(deadline), completion_queue->c_cq,
-      pygrpc_produce_channel_state_change_tag(tag));
-  Py_RETURN_NONE;
-}
-
-PyObject *pygrpc_Channel_target(Channel *self) {
-  char *target = grpc_channel_get_target(self->c_chan);
-  PyObject *py_target = PyString_FromString(target);
-  gpr_free(target);
-  return py_target;
-}
diff --git a/src/python/grpcio/grpc/_adapter/_c/types/channel_credentials.c b/src/python/grpcio/grpc/_adapter/_c/types/channel_credentials.c
deleted file mode 100644
index 83b1fc0406..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types/channel_credentials.c
+++ /dev/null
@@ -1,165 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-#include <grpc/grpc_security.h>
-
-
-PyMethodDef pygrpc_ChannelCredentials_methods[] = {
-    {"google_default", (PyCFunction)pygrpc_ChannelCredentials_google_default,
-     METH_CLASS|METH_NOARGS, ""},
-    {"ssl", (PyCFunction)pygrpc_ChannelCredentials_ssl,
-     METH_CLASS|METH_KEYWORDS, ""},
-    {"composite", (PyCFunction)pygrpc_ChannelCredentials_composite,
-     METH_CLASS|METH_KEYWORDS, ""},
-    {NULL}
-};
-
-const char pygrpc_ChannelCredentials_doc[] = "";
-PyTypeObject pygrpc_ChannelCredentials_type = {
-    PyObject_HEAD_INIT(NULL)
-    0,                                        /* ob_size */
-    "ChannelCredentials",                     /* tp_name */
-    sizeof(ChannelCredentials),               /* tp_basicsize */
-    0,                                        /* tp_itemsize */
-    (destructor)pygrpc_ChannelCredentials_dealloc, /* tp_dealloc */
-    0,                                        /* tp_print */
-    0,                                        /* tp_getattr */
-    0,                                        /* tp_setattr */
-    0,                                        /* tp_compare */
-    0,                                        /* tp_repr */
-    0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
-    0,                                        /* tp_as_mapping */
-    0,                                        /* tp_hash */
-    0,                                        /* tp_call */
-    0,                                        /* tp_str */
-    0,                                        /* tp_getattro */
-    0,                                        /* tp_setattro */
-    0,                                        /* tp_as_buffer */
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
-    pygrpc_ChannelCredentials_doc,             /* tp_doc */
-    0,                                        /* tp_traverse */
-    0,                                        /* tp_clear */
-    0,                                        /* tp_richcompare */
-    0,                                        /* tp_weaklistoffset */
-    0,                                        /* tp_iter */
-    0,                                        /* tp_iternext */
-    pygrpc_ChannelCredentials_methods,         /* tp_methods */
-    0,                                        /* tp_members */
-    0,                                        /* tp_getset */
-    0,                                        /* tp_base */
-    0,                                        /* tp_dict */
-    0,                                        /* tp_descr_get */
-    0,                                        /* tp_descr_set */
-    0,                                        /* tp_dictoffset */
-    0,                                        /* tp_init */
-    0,                                        /* tp_alloc */
-    0                                         /* tp_new */
-};
-
-void pygrpc_ChannelCredentials_dealloc(ChannelCredentials *self) {
-  grpc_channel_credentials_release(self->c_creds);
-  self->ob_type->tp_free((PyObject *)self);
-}
-
-ChannelCredentials *pygrpc_ChannelCredentials_google_default(
-    PyTypeObject *type, PyObject *ignored) {
-  ChannelCredentials *self = (ChannelCredentials *)type->tp_alloc(type, 0);
-  self->c_creds = grpc_google_default_credentials_create();
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(PyExc_RuntimeError,
-                    "couldn't create Google default credentials");
-    return NULL;
-  }
-  return self;
-}
-
-ChannelCredentials *pygrpc_ChannelCredentials_ssl(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  ChannelCredentials *self;
-  const char *root_certs;
-  const char *private_key = NULL;
-  const char *cert_chain = NULL;
-  grpc_ssl_pem_key_cert_pair key_cert_pair;
-  static char *keywords[] = {"root_certs", "private_key", "cert_chain", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "z|zz:ssl", keywords,
-        &root_certs, &private_key, &cert_chain)) {
-    return NULL;
-  }
-  self = (ChannelCredentials *)type->tp_alloc(type, 0);
-  if (private_key && cert_chain) {
-    key_cert_pair.private_key = private_key;
-    key_cert_pair.cert_chain = cert_chain;
-    self->c_creds =
-        grpc_ssl_credentials_create(root_certs, &key_cert_pair, NULL);
-  } else {
-    self->c_creds = grpc_ssl_credentials_create(root_certs, NULL, NULL);
-  }
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(PyExc_RuntimeError, "couldn't create ssl credentials");
-    return NULL;
-  }
-  return self;
-}
-
-ChannelCredentials *pygrpc_ChannelCredentials_composite(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  ChannelCredentials *self;
-  ChannelCredentials *creds1;
-  CallCredentials *creds2;
-  static char *keywords[] = {"creds1", "creds2", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O!O!:composite", keywords,
-        &pygrpc_ChannelCredentials_type, &creds1,
-        &pygrpc_CallCredentials_type, &creds2)) {
-    return NULL;
-  }
-  self = (ChannelCredentials *)type->tp_alloc(type, 0);
-  self->c_creds =
-      grpc_composite_channel_credentials_create(
-          creds1->c_creds, creds2->c_creds, NULL);
-  if (!self->c_creds) {
-    Py_DECREF(self);
-    PyErr_SetString(
-        PyExc_RuntimeError, "couldn't create composite credentials");
-    return NULL;
-  }
-  return self;
-}
-
diff --git a/src/python/grpcio/grpc/_adapter/_c/types/completion_queue.c b/src/python/grpcio/grpc/_adapter/_c/types/completion_queue.c
deleted file mode 100644
index d8bb89ca4b..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types/completion_queue.c
+++ /dev/null
@@ -1,124 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-
-
-PyMethodDef pygrpc_CompletionQueue_methods[] = {
-    {"next", (PyCFunction)pygrpc_CompletionQueue_next, METH_KEYWORDS, ""},
-    {"shutdown", (PyCFunction)pygrpc_CompletionQueue_shutdown, METH_NOARGS, ""},
-    {NULL}
-};
-const char pygrpc_CompletionQueue_doc[] =
-    "See grpc._adapter._types.CompletionQueue.";
-PyTypeObject pygrpc_CompletionQueue_type = {
-    PyObject_HEAD_INIT(NULL)
-    0,                                        /* ob_size */
-    "CompletionQueue",                        /* tp_name */
-    sizeof(CompletionQueue),                  /* tp_basicsize */
-    0,                                        /* tp_itemsize */
-    (destructor)pygrpc_CompletionQueue_dealloc, /* tp_dealloc */
-    0,                                        /* tp_print */
-    0,                                        /* tp_getattr */
-    0,                                        /* tp_setattr */
-    0,                                        /* tp_compare */
-    0,                                        /* tp_repr */
-    0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
-    0,                                        /* tp_as_mapping */
-    0,                                        /* tp_hash */
-    0,                                        /* tp_call */
-    0,                                        /* tp_str */
-    0,                                        /* tp_getattro */
-    0,                                        /* tp_setattro */
-    0,                                        /* tp_as_buffer */
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
-    pygrpc_CompletionQueue_doc,               /* tp_doc */
-    0,                                        /* tp_traverse */
-    0,                                        /* tp_clear */
-    0,                                        /* tp_richcompare */
-    0,                                        /* tp_weaklistoffset */
-    0,                                        /* tp_iter */
-    0,                                        /* tp_iternext */
-    pygrpc_CompletionQueue_methods,           /* tp_methods */
-    0,                                        /* tp_members */
-    0,                                        /* tp_getset */
-    0,                                        /* tp_base */
-    0,                                        /* tp_dict */
-    0,                                        /* tp_descr_get */
-    0,                                        /* tp_descr_set */
-    0,                                        /* tp_dictoffset */
-    0,                                        /* tp_init */
-    0,                                        /* tp_alloc */
-    (newfunc)pygrpc_CompletionQueue_new       /* tp_new */
-};
-
-CompletionQueue *pygrpc_CompletionQueue_new(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  CompletionQueue *self = (CompletionQueue *)type->tp_alloc(type, 0);
-  self->c_cq = grpc_completion_queue_create(NULL);
-  return self;
-}
-
-void pygrpc_CompletionQueue_dealloc(CompletionQueue *self) {
-  grpc_completion_queue_destroy(self->c_cq);
-  self->ob_type->tp_free((PyObject *)self);
-}
-
-PyObject *pygrpc_CompletionQueue_next(
-    CompletionQueue *self, PyObject *args, PyObject *kwargs) {
-  double deadline;
-  grpc_event event;
-  PyObject *transliterated_event;
-  static char *keywords[] = {"deadline", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "d:next", keywords,
-                                   &deadline)) {
-    return NULL;
-  }
-  Py_BEGIN_ALLOW_THREADS;
-  event = grpc_completion_queue_next(
-      self->c_cq, pygrpc_cast_double_to_gpr_timespec(deadline), NULL);
-  Py_END_ALLOW_THREADS;
-  transliterated_event = pygrpc_consume_event(event);
-  return transliterated_event;
-}
-
-PyObject *pygrpc_CompletionQueue_shutdown(
-    CompletionQueue *self, PyObject *ignored) {
-  grpc_completion_queue_shutdown(self->c_cq);
-  Py_RETURN_NONE;
-}
diff --git a/src/python/grpcio/grpc/_adapter/_c/types/server.c b/src/python/grpcio/grpc/_adapter/_c/types/server.c
deleted file mode 100644
index 8feab8aab1..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types/server.c
+++ /dev/null
@@ -1,196 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-
-
-PyMethodDef pygrpc_Server_methods[] = {
-    {"request_call", (PyCFunction)pygrpc_Server_request_call,
-     METH_KEYWORDS, ""},
-    {"add_http2_port", (PyCFunction)pygrpc_Server_add_http2_port,
-     METH_KEYWORDS, ""},
-    {"start", (PyCFunction)pygrpc_Server_start, METH_NOARGS, ""},
-    {"shutdown", (PyCFunction)pygrpc_Server_shutdown, METH_KEYWORDS, ""},
-    {"cancel_all_calls", (PyCFunction)pygrpc_Server_cancel_all_calls,
-     METH_NOARGS, ""},
-    {NULL}
-};
-const char pygrpc_Server_doc[] = "See grpc._adapter._types.Server.";
-PyTypeObject pygrpc_Server_type = {
-    PyObject_HEAD_INIT(NULL)
-    0,                                        /* ob_size */
-    "Server",                                 /* tp_name */
-    sizeof(Server),                           /* tp_basicsize */
-    0,                                        /* tp_itemsize */
-    (destructor)pygrpc_Server_dealloc,        /* tp_dealloc */
-    0,                                        /* tp_print */
-    0,                                        /* tp_getattr */
-    0,                                        /* tp_setattr */
-    0,                                        /* tp_compare */
-    0,                                        /* tp_repr */
-    0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
-    0,                                        /* tp_as_mapping */
-    0,                                        /* tp_hash */
-    0,                                        /* tp_call */
-    0,                                        /* tp_str */
-    0,                                        /* tp_getattro */
-    0,                                        /* tp_setattro */
-    0,                                        /* tp_as_buffer */
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
-    pygrpc_Server_doc,                        /* tp_doc */
-    0,                                        /* tp_traverse */
-    0,                                        /* tp_clear */
-    0,                                        /* tp_richcompare */
-    0,                                        /* tp_weaklistoffset */
-    0,                                        /* tp_iter */
-    0,                                        /* tp_iternext */
-    pygrpc_Server_methods,                    /* tp_methods */
-    0,                                        /* tp_members */
-    0,                                        /* tp_getset */
-    0,                                        /* tp_base */
-    0,                                        /* tp_dict */
-    0,                                        /* tp_descr_get */
-    0,                                        /* tp_descr_set */
-    0,                                        /* tp_dictoffset */
-    0,                                        /* tp_init */
-    0,                                        /* tp_alloc */
-    (newfunc)pygrpc_Server_new                /* tp_new */
-};
-
-Server *pygrpc_Server_new(PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  Server *self;
-  CompletionQueue *cq;
-  PyObject *py_args;
-  grpc_channel_args c_args;
-  char *keywords[] = {"cq", "args", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O!O:Server", keywords,
-        &pygrpc_CompletionQueue_type, &cq, &py_args)) {
-    return NULL;
-  }
-  if (!pygrpc_produce_channel_args(py_args, &c_args)) {
-    return NULL;
-  }
-  self = (Server *)type->tp_alloc(type, 0);
-  self->c_serv = grpc_server_create(&c_args, NULL);
-  grpc_server_register_completion_queue(self->c_serv, cq->c_cq, NULL);
-  pygrpc_discard_channel_args(c_args);
-  self->cq = cq;
-  Py_INCREF(self->cq);
-  self->shutdown_called = 0;
-  return self;
-}
-
-void pygrpc_Server_dealloc(Server *self) {
-  grpc_server_destroy(self->c_serv);
-  Py_XDECREF(self->cq);
-  self->ob_type->tp_free((PyObject *)self);
-}
-
-PyObject *pygrpc_Server_request_call(
-    Server *self, PyObject *args, PyObject *kwargs) {
-  CompletionQueue *cq;
-  PyObject *user_tag;
-  pygrpc_tag *tag;
-  Call *empty_call;
-  grpc_call_error errcode;
-  static char *keywords[] = {"cq", "tag", NULL};
-  if (!PyArg_ParseTupleAndKeywords(
-      args, kwargs, "O!O", keywords,
-      &pygrpc_CompletionQueue_type, &cq, &user_tag)) {
-    return NULL;
-  }
-  empty_call = pygrpc_Call_new_empty(cq);
-  tag = pygrpc_produce_request_tag(user_tag, empty_call);
-  errcode = grpc_server_request_call(
-      self->c_serv, &tag->call->c_call, &tag->request_call_details,
-      &tag->request_metadata, tag->call->cq->c_cq, self->cq->c_cq, tag);
-  Py_DECREF(empty_call);
-  return PyInt_FromLong(errcode);
-}
-
-PyObject *pygrpc_Server_add_http2_port(
-    Server *self, PyObject *args, PyObject *kwargs) {
-  const char *addr;
-  ServerCredentials *creds = NULL;
-  int port;
-  static char *keywords[] = {"addr", "creds", NULL};
-  if (!PyArg_ParseTupleAndKeywords(
-      args, kwargs, "s|O!:add_http2_port", keywords,
-      &addr, &pygrpc_ServerCredentials_type, &creds)) {
-    return NULL;
-  }
-  if (creds) {
-    port = grpc_server_add_secure_http2_port(
-        self->c_serv, addr, creds->c_creds);
-  } else {
-    port = grpc_server_add_insecure_http2_port(self->c_serv, addr);
-  }
-  return PyInt_FromLong(port);
-
-}
-
-PyObject *pygrpc_Server_start(Server *self, PyObject *ignored) {
-  grpc_server_start(self->c_serv);
-  self->shutdown_called = 0;
-  Py_RETURN_NONE;
-}
-
-PyObject *pygrpc_Server_shutdown(
-    Server *self, PyObject *args, PyObject *kwargs) {
-  PyObject *user_tag;
-  pygrpc_tag *tag;
-  static char *keywords[] = {"tag", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O", keywords, &user_tag)) {
-    return NULL;
-  }
-  tag = pygrpc_produce_server_shutdown_tag(user_tag);
-  grpc_server_shutdown_and_notify(self->c_serv, self->cq->c_cq, tag);
-  self->shutdown_called = 1;
-  Py_RETURN_NONE;
-}
-
-PyObject *pygrpc_Server_cancel_all_calls(Server *self, PyObject *unused) {
-  if (!self->shutdown_called) {
-    PyErr_SetString(
-        PyExc_RuntimeError,
-        "shutdown must have been called prior to calling cancel_all_calls!");
-    return NULL;
-  }
-  grpc_server_cancel_all_calls(self->c_serv);
-  Py_RETURN_NONE;
-}
diff --git a/src/python/grpcio/grpc/_adapter/_c/types/server_credentials.c b/src/python/grpcio/grpc/_adapter/_c/types/server_credentials.c
deleted file mode 100644
index df51a99b6a..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/types/server_credentials.c
+++ /dev/null
@@ -1,137 +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 "grpc/_adapter/_c/types.h"
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-#include <grpc/grpc_security.h>
-#include <grpc/support/alloc.h>
-
-
-PyMethodDef pygrpc_ServerCredentials_methods[] = {
-    {"ssl", (PyCFunction)pygrpc_ServerCredentials_ssl,
-     METH_CLASS|METH_KEYWORDS, ""},
-    {NULL}
-};
-const char pygrpc_ServerCredentials_doc[] = "";
-PyTypeObject pygrpc_ServerCredentials_type = {
-    PyObject_HEAD_INIT(NULL)
-    0,                                        /* ob_size */
-    "ServerCredentials",                      /* tp_name */
-    sizeof(ServerCredentials),                /* tp_basicsize */
-    0,                                        /* tp_itemsize */
-    (destructor)pygrpc_ServerCredentials_dealloc, /* tp_dealloc */
-    0,                                        /* tp_print */
-    0,                                        /* tp_getattr */
-    0,                                        /* tp_setattr */
-    0,                                        /* tp_compare */
-    0,                                        /* tp_repr */
-    0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
-    0,                                        /* tp_as_mapping */
-    0,                                        /* tp_hash */
-    0,                                        /* tp_call */
-    0,                                        /* tp_str */
-    0,                                        /* tp_getattro */
-    0,                                        /* tp_setattro */
-    0,                                        /* tp_as_buffer */
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
-    pygrpc_ServerCredentials_doc,             /* tp_doc */
-    0,                                        /* tp_traverse */
-    0,                                        /* tp_clear */
-    0,                                        /* tp_richcompare */
-    0,                                        /* tp_weaklistoffset */
-    0,                                        /* tp_iter */
-    0,                                        /* tp_iternext */
-    pygrpc_ServerCredentials_methods,         /* tp_methods */
-    0,                                        /* tp_members */
-    0,                                        /* tp_getset */
-    0,                                        /* tp_base */
-    0,                                        /* tp_dict */
-    0,                                        /* tp_descr_get */
-    0,                                        /* tp_descr_set */
-    0,                                        /* tp_dictoffset */
-    0,                                        /* tp_init */
-    0,                                        /* tp_alloc */
-    0                                         /* tp_new */
-};
-
-void pygrpc_ServerCredentials_dealloc(ServerCredentials *self) {
-  grpc_server_credentials_release(self->c_creds);
-  self->ob_type->tp_free((PyObject *)self);
-}
-
-ServerCredentials *pygrpc_ServerCredentials_ssl(
-    PyTypeObject *type, PyObject *args, PyObject *kwargs) {
-  ServerCredentials *self;
-  const char *root_certs;
-  PyObject *py_key_cert_pairs;
-  grpc_ssl_pem_key_cert_pair *key_cert_pairs;
-  int force_client_auth;
-  size_t num_key_cert_pairs;
-  size_t i;
-  static char *keywords[] = {
-      "root_certs", "key_cert_pairs", "force_client_auth", NULL};
-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "zOi:ssl", keywords,
-	&root_certs, &py_key_cert_pairs, &force_client_auth)) {
-    return NULL;
-  }
-  if (!PyList_Check(py_key_cert_pairs)) {
-    PyErr_SetString(PyExc_TypeError, "expected a list of 2-tuples of strings");
-    return NULL;
-  }
-  num_key_cert_pairs = PyList_Size(py_key_cert_pairs);
-  key_cert_pairs =
-      gpr_malloc(sizeof(grpc_ssl_pem_key_cert_pair) * num_key_cert_pairs);
-  for (i = 0; i < num_key_cert_pairs; ++i) {
-    PyObject *item = PyList_GET_ITEM(py_key_cert_pairs, i);
-    const char *key;
-    const char *cert;
-    if (!PyArg_ParseTuple(item, "zz", &key, &cert)) {
-      gpr_free(key_cert_pairs);
-      PyErr_SetString(PyExc_TypeError,
-                      "expected a list of 2-tuples of strings");
-      return NULL;
-    }
-    key_cert_pairs[i].private_key = key;
-    key_cert_pairs[i].cert_chain = cert;
-  }
-
-  self = (ServerCredentials *)type->tp_alloc(type, 0);
-  self->c_creds = grpc_ssl_server_credentials_create(
-      root_certs, key_cert_pairs, num_key_cert_pairs, force_client_auth, NULL);
-  gpr_free(key_cert_pairs);
-  return self;
-}
diff --git a/src/python/grpcio/grpc/_adapter/_c/utility.c b/src/python/grpcio/grpc/_adapter/_c/utility.c
deleted file mode 100644
index 590f7e013a..0000000000
--- a/src/python/grpcio/grpc/_adapter/_c/utility.c
+++ /dev/null
@@ -1,524 +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 <math.h>
-#include <string.h>
-
-#define PY_SSIZE_T_CLEAN
-#include <Python.h>
-#include <grpc/grpc.h>
-#include <grpc/byte_buffer_reader.h>
-#include <grpc/support/alloc.h>
-#include <grpc/support/slice.h>
-#include <grpc/support/time.h>
-#include <grpc/support/string_util.h>
-
-#include "grpc/_adapter/_c/types.h"
-
-pygrpc_tag *pygrpc_produce_batch_tag(
-    PyObject *user_tag, Call *call, grpc_op *ops, size_t nops) {
-  pygrpc_tag *tag = gpr_malloc(sizeof(pygrpc_tag));
-  tag->user_tag = user_tag;
-  Py_XINCREF(tag->user_tag);
-  tag->call = call;
-  Py_XINCREF(tag->call);
-  tag->ops = gpr_malloc(sizeof(grpc_op)*nops);
-  memcpy(tag->ops, ops, sizeof(grpc_op)*nops);
-  tag->nops = nops;
-  grpc_call_details_init(&tag->request_call_details);
-  grpc_metadata_array_init(&tag->request_metadata);
-  tag->is_new_call = 0;
-  return tag;
-}
-
-pygrpc_tag *pygrpc_produce_request_tag(PyObject *user_tag, Call *empty_call) {
-  pygrpc_tag *tag = gpr_malloc(sizeof(pygrpc_tag));
-  tag->user_tag = user_tag;
-  Py_XINCREF(tag->user_tag);
-  tag->call = empty_call;
-  Py_XINCREF(tag->call);
-  tag->ops = NULL;
-  tag->nops = 0;
-  grpc_call_details_init(&tag->request_call_details);
-  grpc_metadata_array_init(&tag->request_metadata);
-  tag->is_new_call = 1;
-  return tag;
-}
-
-pygrpc_tag *pygrpc_produce_server_shutdown_tag(PyObject *user_tag) {
-  pygrpc_tag *tag = gpr_malloc(sizeof(pygrpc_tag));
-  tag->user_tag = user_tag;
-  Py_XINCREF(tag->user_tag);
-  tag->call = NULL;
-  tag->ops = NULL;
-  tag->nops = 0;
-  grpc_call_details_init(&tag->request_call_details);
-  grpc_metadata_array_init(&tag->request_metadata);
-  tag->is_new_call = 0;
-  return tag;
-}
-
-pygrpc_tag *pygrpc_produce_channel_state_change_tag(PyObject *user_tag) {
-  pygrpc_tag *tag = gpr_malloc(sizeof(pygrpc_tag));
-  tag->user_tag = user_tag;
-  Py_XINCREF(tag->user_tag);
-  tag->call = NULL;
-  tag->ops = NULL;
-  tag->nops = 0;
-  grpc_call_details_init(&tag->request_call_details);
-  grpc_metadata_array_init(&tag->request_metadata);
-  tag->is_new_call = 0;
-  return tag;
-}
-
-void pygrpc_discard_tag(pygrpc_tag *tag) {
-  if (!tag) {
-    return;
-  }
-  Py_XDECREF(tag->user_tag);
-  Py_XDECREF(tag->call);
-  gpr_free(tag->ops);
-  grpc_call_details_destroy(&tag->request_call_details);
-  grpc_metadata_array_destroy(&tag->request_metadata);
-  gpr_free(tag);
-}
-
-PyObject *pygrpc_consume_event(grpc_event event) {
-  pygrpc_tag *tag;
-  PyObject *result;
-  if (event.type == GRPC_QUEUE_TIMEOUT) {
-    Py_RETURN_NONE;
-  }
-  tag = event.tag;
-  switch (event.type) {
-  case GRPC_QUEUE_SHUTDOWN:
-    result = Py_BuildValue("iOOOOO", GRPC_QUEUE_SHUTDOWN,
-                           Py_None, Py_None, Py_None, Py_None, Py_True);
-    break;
-  case GRPC_OP_COMPLETE:
-    if (tag->is_new_call) {
-      result = Py_BuildValue(
-          "iOO(ssd)[(iNOOOO)]O", GRPC_OP_COMPLETE, tag->user_tag, tag->call,
-          tag->request_call_details.method, tag->request_call_details.host,
-          pygrpc_cast_gpr_timespec_to_double(tag->request_call_details.deadline),
-          GRPC_OP_RECV_INITIAL_METADATA,
-          pygrpc_cast_metadata_array_to_pyseq(tag->request_metadata), Py_None,
-          Py_None, Py_None, Py_None,
-          event.success ? Py_True : Py_False);
-    } else {
-      result = Py_BuildValue("iOOONO", GRPC_OP_COMPLETE, tag->user_tag,
-          tag->call ? (PyObject*)tag->call : Py_None, Py_None,
-          pygrpc_consume_ops(tag->ops, tag->nops),
-          event.success ? Py_True : Py_False);
-    }
-    break;
-  default:
-    PyErr_SetString(PyExc_ValueError,
-                    "unknown completion type; could not translate event");
-    return NULL;
-  }
-  pygrpc_discard_tag(tag);
-  return result;
-}
-
-int pygrpc_produce_op(PyObject *op, grpc_op *result) {
-  static const int OP_TUPLE_SIZE = 6;
-  static const int STATUS_TUPLE_SIZE = 2;
-  static const int TYPE_INDEX = 0;
-  static const int INITIAL_METADATA_INDEX = 1;
-  static const int TRAILING_METADATA_INDEX = 2;
-  static const int MESSAGE_INDEX = 3;
-  static const int STATUS_INDEX = 4;
-  static const int STATUS_CODE_INDEX = 0;
-  static const int STATUS_DETAILS_INDEX = 1;
-  static const int WRITE_FLAGS_INDEX = 5;
-  int type;
-  Py_ssize_t message_size;
-  char *message;
-  char *status_details;
-  gpr_slice message_slice;
-  grpc_op c_op;
-  if (!PyTuple_Check(op)) {
-    PyErr_SetString(PyExc_TypeError, "expected tuple op");
-    return 0;
-  }
-  if (PyTuple_Size(op) != OP_TUPLE_SIZE) {
-    char *buf;
-    gpr_asprintf(&buf, "expected tuple op of length %d", OP_TUPLE_SIZE);
-    PyErr_SetString(PyExc_ValueError, buf);
-    gpr_free(buf);
-    return 0;
-  }
-  type = PyInt_AsLong(PyTuple_GET_ITEM(op, TYPE_INDEX));
-  if (PyErr_Occurred()) {
-    return 0;
-  }
-  c_op.op = type;
-  c_op.reserved = NULL;
-  c_op.flags = PyInt_AsLong(PyTuple_GET_ITEM(op, WRITE_FLAGS_INDEX));
-  if (PyErr_Occurred()) {
-    return 0;
-  }
-  switch (type) {
-  case GRPC_OP_SEND_INITIAL_METADATA:
-    if (!pygrpc_cast_pyseq_to_send_metadata(
-            PyTuple_GetItem(op, INITIAL_METADATA_INDEX),
-            &c_op.data.send_initial_metadata.metadata,
-            &c_op.data.send_initial_metadata.count)) {
-      return 0;
-    }
-    break;
-  case GRPC_OP_SEND_MESSAGE:
-    PyString_AsStringAndSize(
-        PyTuple_GET_ITEM(op, MESSAGE_INDEX), &message, &message_size);
-    message_slice = gpr_slice_from_copied_buffer(message, message_size);
-    c_op.data.send_message = grpc_raw_byte_buffer_create(&message_slice, 1);
-    gpr_slice_unref(message_slice);
-    break;
-  case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
-    /* Don't need to fill in any other fields. */
-    break;
-  case GRPC_OP_SEND_STATUS_FROM_SERVER:
-    if (!pygrpc_cast_pyseq_to_send_metadata(
-            PyTuple_GetItem(op, TRAILING_METADATA_INDEX),
-            &c_op.data.send_status_from_server.trailing_metadata,
-            &c_op.data.send_status_from_server.trailing_metadata_count)) {
-      return 0;
-    }
-    if (!PyTuple_Check(PyTuple_GET_ITEM(op, STATUS_INDEX))) {
-      char *buf;
-      gpr_asprintf(&buf, "expected tuple status in op of length %d",
-                   STATUS_TUPLE_SIZE);
-      PyErr_SetString(PyExc_ValueError, buf);
-      gpr_free(buf);
-      return 0;
-    }
-    c_op.data.send_status_from_server.status = PyInt_AsLong(
-        PyTuple_GET_ITEM(PyTuple_GET_ITEM(op, STATUS_INDEX), STATUS_CODE_INDEX));
-    status_details = PyString_AsString(
-        PyTuple_GET_ITEM(PyTuple_GET_ITEM(op, STATUS_INDEX), STATUS_DETAILS_INDEX));
-    if (PyErr_Occurred()) {
-      return 0;
-    }
-    c_op.data.send_status_from_server.status_details =
-        gpr_malloc(strlen(status_details) + 1);
-    strcpy((char *)c_op.data.send_status_from_server.status_details,
-           status_details);
-    break;
-  case GRPC_OP_RECV_INITIAL_METADATA:
-    c_op.data.recv_initial_metadata = gpr_malloc(sizeof(grpc_metadata_array));
-    grpc_metadata_array_init(c_op.data.recv_initial_metadata);
-    break;
-  case GRPC_OP_RECV_MESSAGE:
-    c_op.data.recv_message = gpr_malloc(sizeof(grpc_byte_buffer *));
-    break;
-  case GRPC_OP_RECV_STATUS_ON_CLIENT:
-    c_op.data.recv_status_on_client.trailing_metadata =
-        gpr_malloc(sizeof(grpc_metadata_array));
-    grpc_metadata_array_init(c_op.data.recv_status_on_client.trailing_metadata);
-    c_op.data.recv_status_on_client.status =
-        gpr_malloc(sizeof(grpc_status_code *));
-    c_op.data.recv_status_on_client.status_details =
-        gpr_malloc(sizeof(char *));
-    *c_op.data.recv_status_on_client.status_details = NULL;
-    c_op.data.recv_status_on_client.status_details_capacity =
-        gpr_malloc(sizeof(size_t));
-    *c_op.data.recv_status_on_client.status_details_capacity = 0;
-    break;
-  case GRPC_OP_RECV_CLOSE_ON_SERVER:
-    c_op.data.recv_close_on_server.cancelled = gpr_malloc(sizeof(int));
-    break;
-  default:
-    return 0;
-  }
-  *result = c_op;
-  return 1;
-}
-
-void pygrpc_discard_op(grpc_op op) {
-  size_t i;
-  switch(op.op) {
-  case GRPC_OP_SEND_INITIAL_METADATA:
-    /* Whenever we produce send-metadata, we allocate new strings (to handle
-       arbitrary sequence input as opposed to just lists or just tuples). We
-       thus must free those elements. */
-    for (i = 0; i < op.data.send_initial_metadata.count; ++i) {
-      gpr_free((void *)op.data.send_initial_metadata.metadata[i].key);
-      gpr_free((void *)op.data.send_initial_metadata.metadata[i].value);
-    }
-    gpr_free(op.data.send_initial_metadata.metadata);
-    break;
-  case GRPC_OP_SEND_MESSAGE:
-    grpc_byte_buffer_destroy(op.data.send_message);
-    break;
-  case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
-    /* Don't need to free any fields. */
-    break;
-  case GRPC_OP_SEND_STATUS_FROM_SERVER:
-    /* Whenever we produce send-metadata, we allocate new strings (to handle
-       arbitrary sequence input as opposed to just lists or just tuples). We
-       thus must free those elements. */
-    for (i = 0; i < op.data.send_status_from_server.trailing_metadata_count;
-         ++i) {
-      gpr_free(
-          (void *)op.data.send_status_from_server.trailing_metadata[i].key);
-      gpr_free(
-          (void *)op.data.send_status_from_server.trailing_metadata[i].value);
-    }
-    gpr_free(op.data.send_status_from_server.trailing_metadata);
-    gpr_free((char *)op.data.send_status_from_server.status_details);
-    break;
-  case GRPC_OP_RECV_INITIAL_METADATA:
-    grpc_metadata_array_destroy(op.data.recv_initial_metadata);
-    gpr_free(op.data.recv_initial_metadata);
-    break;
-  case GRPC_OP_RECV_MESSAGE:
-    grpc_byte_buffer_destroy(*op.data.recv_message);
-    gpr_free(op.data.recv_message);
-    break;
-  case GRPC_OP_RECV_STATUS_ON_CLIENT:
-    grpc_metadata_array_destroy(op.data.recv_status_on_client.trailing_metadata);
-    gpr_free(op.data.recv_status_on_client.trailing_metadata);
-    gpr_free(op.data.recv_status_on_client.status);
-    gpr_free(*op.data.recv_status_on_client.status_details);
-    gpr_free(op.data.recv_status_on_client.status_details);
-    gpr_free(op.data.recv_status_on_client.status_details_capacity);
-    break;
-  case GRPC_OP_RECV_CLOSE_ON_SERVER:
-    gpr_free(op.data.recv_close_on_server.cancelled);
-    break;
-  }
-}
-
-PyObject *pygrpc_consume_ops(grpc_op *op, size_t nops) {
-  static const int TYPE_INDEX = 0;
-  static const int INITIAL_METADATA_INDEX = 1;
-  static const int TRAILING_METADATA_INDEX = 2;
-  static const int MESSAGE_INDEX = 3;
-  static const int STATUS_INDEX = 4;
-  static const int CANCELLED_INDEX = 5;
-  static const int OPRESULT_LENGTH = 6;
-  PyObject *list;
-  size_t i;
-  size_t j;
-  char *bytes;
-  size_t bytes_size;
-  PyObject *results = PyList_New(nops);
-  if (!results) {
-    return NULL;
-  }
-  for (i = 0; i < nops; ++i) {
-    PyObject *result = PyTuple_Pack(OPRESULT_LENGTH, Py_None, Py_None, Py_None,
-                                    Py_None, Py_None, Py_None);
-    PyTuple_SetItem(result, TYPE_INDEX, PyInt_FromLong(op[i].op));
-    switch(op[i].op) {
-    case GRPC_OP_RECV_INITIAL_METADATA:
-      PyTuple_SetItem(result, INITIAL_METADATA_INDEX,
-                      list=PyList_New(op[i].data.recv_initial_metadata->count));
-      for (j = 0; j < op[i].data.recv_initial_metadata->count; ++j) {
-        grpc_metadata md = op[i].data.recv_initial_metadata->metadata[j];
-        PyList_SetItem(list, j, Py_BuildValue("ss#", md.key, md.value,
-                                              (Py_ssize_t)md.value_length));
-      }
-      break;
-    case GRPC_OP_RECV_MESSAGE:
-      if (*op[i].data.recv_message) {
-        pygrpc_byte_buffer_to_bytes(
-            *op[i].data.recv_message, &bytes, &bytes_size);
-        PyTuple_SetItem(result, MESSAGE_INDEX,
-                        PyString_FromStringAndSize(bytes, bytes_size));
-        gpr_free(bytes);
-      } else {
-        PyTuple_SetItem(result, MESSAGE_INDEX, Py_BuildValue(""));
-      }
-      break;
-    case GRPC_OP_RECV_STATUS_ON_CLIENT:
-      PyTuple_SetItem(
-          result, TRAILING_METADATA_INDEX,
-          list = PyList_New(op[i].data.recv_status_on_client.trailing_metadata->count));
-      for (j = 0; j < op[i].data.recv_status_on_client.trailing_metadata->count; ++j) {
-        grpc_metadata md =
-            op[i].data.recv_status_on_client.trailing_metadata->metadata[j];
-        PyList_SetItem(list, j, Py_BuildValue("ss#", md.key, md.value,
-                                              (Py_ssize_t)md.value_length));
-      }
-      PyTuple_SetItem(
-          result, STATUS_INDEX, Py_BuildValue(
-              "is", *op[i].data.recv_status_on_client.status,
-              *op[i].data.recv_status_on_client.status_details));
-      break;
-    case GRPC_OP_RECV_CLOSE_ON_SERVER:
-      PyTuple_SetItem(
-          result, CANCELLED_INDEX,
-          PyBool_FromLong(*op[i].data.recv_close_on_server.cancelled));
-      break;
-    default:
-      break;
-    }
-    pygrpc_discard_op(op[i]);
-    PyList_SetItem(results, i, result);
-  }
-  return results;
-}
-
-double pygrpc_cast_gpr_timespec_to_double(gpr_timespec timespec) {
-  timespec = gpr_convert_clock_type(timespec, GPR_CLOCK_REALTIME);
-  return timespec.tv_sec + 1e-9*timespec.tv_nsec;
-}
-
-/* Because C89 doesn't have a way to check for infinity... */
-static int pygrpc_isinf(double x) {
-  return x * 0 != 0;
-}
-
-gpr_timespec pygrpc_cast_double_to_gpr_timespec(double seconds) {
-  gpr_timespec result;
-  if (pygrpc_isinf(seconds)) {
-    result = seconds > 0.0 ? gpr_inf_future(GPR_CLOCK_REALTIME)
-                           : gpr_inf_past(GPR_CLOCK_REALTIME);
-  } else {
-    result.tv_sec = (time_t)seconds;
-    result.tv_nsec = ((seconds - result.tv_sec) * 1e9);
-    result.clock_type = GPR_CLOCK_REALTIME;
-  }
-  return result;
-}
-
-int pygrpc_produce_channel_args(PyObject *py_args, grpc_channel_args *c_args) {
-  size_t num_args = PyList_Size(py_args);
-  size_t i;
-  grpc_channel_args args;
-  args.num_args = num_args;
-  args.args = gpr_malloc(sizeof(grpc_arg) * num_args);
-  for (i = 0; i < args.num_args; ++i) {
-    char *key;
-    PyObject *value;
-    if (!PyArg_ParseTuple(PyList_GetItem(py_args, i), "zO", &key, &value)) {
-      gpr_free(args.args);
-      args.num_args = 0;
-      args.args = NULL;
-      PyErr_SetString(PyExc_TypeError,
-                      "expected a list of 2-tuple of str and str|int|None");
-      return 0;
-    }
-    args.args[i].key = key;
-    if (PyInt_Check(value)) {
-      args.args[i].type = GRPC_ARG_INTEGER;
-      args.args[i].value.integer = PyInt_AsLong(value);
-    } else if (PyString_Check(value)) {
-      args.args[i].type = GRPC_ARG_STRING;
-      args.args[i].value.string = PyString_AsString(value);
-    } else if (value == Py_None) {
-      --args.num_args;
-      --i;
-      continue;
-    } else {
-      gpr_free(args.args);
-      args.num_args = 0;
-      args.args = NULL;
-      PyErr_SetString(PyExc_TypeError,
-                      "expected a list of 2-tuple of str and str|int|None");
-      return 0;
-    }
-  }
-  *c_args = args;
-  return 1;
-}
-
-void pygrpc_discard_channel_args(grpc_channel_args args) {
-  gpr_free(args.args);
-}
-
-int pygrpc_cast_pyseq_to_send_metadata(
-    PyObject *pyseq, grpc_metadata **metadata, size_t *count) {
-  size_t i;
-  Py_ssize_t value_length;
-  char *key;
-  char *value;
-  if (!PySequence_Check(pyseq)) {
-    return 0;
-  }
-  *count = PySequence_Size(pyseq);
-  *metadata = gpr_malloc(sizeof(grpc_metadata) * *count);
-  for (i = 0; i < *count; ++i) {
-    PyObject *item = PySequence_GetItem(pyseq, i);
-    if (!PyArg_ParseTuple(item, "ss#", &key, &value, &value_length)) {
-      Py_DECREF(item);
-      gpr_free(*metadata);
-      *count = 0;
-      *metadata = NULL;
-      return 0;
-    } else {
-      (*metadata)[i].key = gpr_strdup(key);
-      (*metadata)[i].value = gpr_malloc(value_length);
-      memcpy((void *)(*metadata)[i].value, value, value_length);
-      Py_DECREF(item);
-    }
-    (*metadata)[i].value_length = value_length;
-  }
-  return 1;
-}
-
-PyObject *pygrpc_cast_metadata_array_to_pyseq(grpc_metadata_array metadata) {
-  PyObject *result = PyTuple_New(metadata.count);
-  size_t i;
-  for (i = 0; i < metadata.count; ++i) {
-    PyTuple_SetItem(
-        result, i, Py_BuildValue(
-            "ss#", metadata.metadata[i].key, metadata.metadata[i].value,
-            (Py_ssize_t)metadata.metadata[i].value_length));
-    if (PyErr_Occurred()) {
-      Py_DECREF(result);
-      return NULL;
-    }
-  }
-  return result;
-}
-
-void pygrpc_byte_buffer_to_bytes(
-    grpc_byte_buffer *buffer, char **result, size_t *result_size) {
-  grpc_byte_buffer_reader reader;
-  gpr_slice slice;
-  char *read_result = NULL;
-  size_t size = 0;
-  grpc_byte_buffer_reader_init(&reader, buffer);
-  while (grpc_byte_buffer_reader_next(&reader, &slice)) {
-    read_result = gpr_realloc(read_result, size + GPR_SLICE_LENGTH(slice));
-    memcpy(read_result + size, GPR_SLICE_START_PTR(slice),
-           GPR_SLICE_LENGTH(slice));
-    size = size + GPR_SLICE_LENGTH(slice);
-    gpr_slice_unref(slice);
-  }
-  *result_size = size;
-  *result = read_result;
-}
diff --git a/src/python/grpcio/tests/unit/_adapter/_c_test.py b/src/python/grpcio/grpc/_adapter/_implementations.py
index fe020e2a9c..b85f228bf6 100644
--- a/src/python/grpcio/tests/unit/_adapter/_c_test.py
+++ b/src/python/grpcio/grpc/_adapter/_implementations.py
@@ -27,29 +27,22 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-import time
-import unittest
+import collections
 
-from grpc._adapter import _c
-from grpc._adapter import _types
+from grpc.beta import interfaces
 
+class AuthMetadataContext(collections.namedtuple(
+    'AuthMetadataContext', [
+        'service_url',
+        'method_name'
+    ]), interfaces.GRPCAuthMetadataContext):
+  pass
 
-class CTypeSmokeTest(unittest.TestCase):
 
-  def testCompletionQueueUpDown(self):
-    completion_queue = _c.CompletionQueue()
-    del completion_queue
+class AuthMetadataPluginCallback(interfaces.GRPCAuthMetadataContext):
 
-  def testServerUpDown(self):
-    completion_queue = _c.CompletionQueue()
-    serv = _c.Server(completion_queue, [])
-    del serv
-    del completion_queue
+  def __init__(self, callback):
+    self._callback = callback
 
-  def testChannelUpDown(self):
-    channel = _c.Channel('[::]:0', [])
-    del channel
-
-
-if __name__ == '__main__':
-  unittest.main(verbosity=2)
+  def __call__(self, metadata, error):
+    self._callback(metadata, error)
diff --git a/src/python/grpcio/grpc/_adapter/_intermediary_low.py b/src/python/grpcio/grpc/_adapter/_intermediary_low.py
index 5634c2024d..9698ffeabf 100644
--- a/src/python/grpcio/grpc/_adapter/_intermediary_low.py
+++ b/src/python/grpcio/grpc/_adapter/_intermediary_low.py
@@ -115,16 +115,20 @@ class Call(object):
     return call
 
   def invoke(self, completion_queue, metadata_tag, finish_tag):
-    err0 = self._internal.start_batch([
+    err = self._internal.start_batch([
           _types.OpArgs.send_initial_metadata(self._metadata)
       ], _IGNORE_ME_TAG)
-    err1 = self._internal.start_batch([
+    if err != _types.CallError.OK:
+      return err
+    err = self._internal.start_batch([
           _types.OpArgs.recv_initial_metadata()
       ], _TagAdapter(metadata_tag, Event.Kind.METADATA_ACCEPTED))
-    err2 = self._internal.start_batch([
+    if err != _types.CallError.OK:
+      return err
+    err = self._internal.start_batch([
           _types.OpArgs.recv_status_on_client()
       ], _TagAdapter(finish_tag, Event.Kind.FINISH))
-    return err0 if err0 != _types.CallError.OK else err1 if err1 != _types.CallError.OK else err2 if err2 != _types.CallError.OK else _types.CallError.OK
+    return err
 
   def write(self, message, tag, flags):
     return self._internal.start_batch([
@@ -158,7 +162,8 @@ class Call(object):
 
   def status(self, status, tag):
     return self._internal.start_batch([
-          _types.OpArgs.send_status_from_server(self._metadata, status.code, status.details)
+          _types.OpArgs.send_status_from_server(
+              self._metadata, status.code, status.details)
       ], _TagAdapter(tag, Event.Kind.COMPLETE_ACCEPTED))
 
   def cancel(self):
@@ -168,20 +173,17 @@ class Call(object):
     return self._internal.peer()
 
   def set_credentials(self, creds):
-    return self._internal.set_credentials(creds._internal)
+    return self._internal.set_credentials(creds)
 
 
 class Channel(object):
   """Adapter from old _low.Channel interface to new _low.Channel."""
 
-  def __init__(self, hostport, client_credentials, server_host_override=None):
+  def __init__(self, hostport, channel_credentials, server_host_override=None):
     args = []
     if server_host_override:
       args.append((_types.GrpcChannelArgumentKeys.SSL_TARGET_NAME_OVERRIDE.value, server_host_override))
-    creds = None
-    if client_credentials:
-      creds = client_credentials._internal
-    self._internal = _low.Channel(hostport, args, creds)
+    self._internal = _low.Channel(hostport, args, channel_credentials)
 
 
 class CompletionQueue(object):
@@ -192,7 +194,7 @@ class CompletionQueue(object):
 
   def get(self, deadline=None):
     if deadline is None:
-      ev = self._internal.next()
+      ev = self._internal.next(float('+inf'))
     else:
       ev = self._internal.next(deadline)
     if ev is None:
@@ -240,7 +242,7 @@ class Server(object):
     if server_credentials is None:
       return self._internal.add_http2_port(addr, None)
     else:
-      return self._internal.add_http2_port(addr, server_credentials._internal)
+      return self._internal.add_http2_port(addr, server_credentials)
 
   def start(self):
     return self._internal.start()
@@ -248,20 +250,9 @@ class Server(object):
   def service(self, tag):
     return self._internal.request_call(self._internal_cq, _TagAdapter(tag, Event.Kind.SERVICE_ACCEPTED))
 
+  def cancel_all_calls(self):
+    self._internal.cancel_all_calls()
+
   def stop(self):
     return self._internal.shutdown(_TagAdapter(None, Event.Kind.STOP))
 
-
-class ClientCredentials(object):
-  """Adapter from old _low.ClientCredentials interface to new _low.ChannelCredentials."""
-
-  def __init__(self, root_certificates, private_key, certificate_chain):
-    self._internal = _low.ChannelCredentials.ssl(root_certificates, private_key, certificate_chain)
-
-
-class ServerCredentials(object):
-  """Adapter from old _low.ServerCredentials interface to new _low.ServerCredentials."""
-
-  def __init__(self, root_credentials, pair_sequence, force_client_auth):
-    self._internal = _low.ServerCredentials.ssl(
-        root_credentials, list(pair_sequence), force_client_auth)
diff --git a/src/python/grpcio/grpc/_adapter/_low.py b/src/python/grpcio/grpc/_adapter/_low.py
index 57146aaefe..b13d8dd9dd 100644
--- a/src/python/grpcio/grpc/_adapter/_low.py
+++ b/src/python/grpcio/grpc/_adapter/_low.py
@@ -27,36 +27,157 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+import threading
+
 from grpc import _grpcio_metadata
-from grpc._adapter import _c
+from grpc._cython import cygrpc
+from grpc._adapter import _implementations
 from grpc._adapter import _types
 
 _USER_AGENT = 'Python-gRPC-{}'.format(_grpcio_metadata.__version__)
 
-ChannelCredentials = _c.ChannelCredentials
-CallCredentials = _c.CallCredentials
-ServerCredentials = _c.ServerCredentials
+ChannelCredentials = cygrpc.ChannelCredentials
+CallCredentials = cygrpc.CallCredentials
+ServerCredentials = cygrpc.ServerCredentials
+
+channel_credentials_composite = cygrpc.channel_credentials_composite
+call_credentials_composite = cygrpc.call_credentials_composite
+
+def server_credentials_ssl(root_credentials, pair_sequence, force_client_auth):
+  return cygrpc.server_credentials_ssl(
+      root_credentials,
+      [cygrpc.SslPemKeyCertPair(key, pem) for key, pem in pair_sequence],
+      force_client_auth)
+
+def channel_credentials_ssl(
+    root_certificates, private_key, certificate_chain):
+  pair = None
+  if private_key is not None or certificate_chain is not None:
+    pair = cygrpc.SslPemKeyCertPair(private_key, certificate_chain)
+  return cygrpc.channel_credentials_ssl(root_certificates, pair)
+
+
+class _WrappedCygrpcCallback(object):
+
+  def __init__(self, cygrpc_callback):
+    self.is_called = False
+    self.error = None
+    self.is_called_lock = threading.Lock()
+    self.cygrpc_callback = cygrpc_callback
+
+  def _invoke_failure(self, error):
+    # TODO(atash) translate different Exception superclasses into different
+    # status codes.
+    self.cygrpc_callback(
+        cygrpc.Metadata([]), cygrpc.StatusCode.internal, error.message)
+
+  def _invoke_success(self, metadata):
+    try:
+      cygrpc_metadata = cygrpc.Metadata(
+          cygrpc.Metadatum(key, value)
+          for key, value in metadata)
+    except Exception as error:
+      self._invoke_failure(error)
+      return
+    self.cygrpc_callback(cygrpc_metadata, cygrpc.StatusCode.ok, '')
+
+  def __call__(self, metadata, error):
+    with self.is_called_lock:
+      if self.is_called:
+        raise RuntimeError('callback should only ever be invoked once')
+      if self.error:
+        self._invoke_failure(self.error)
+        return
+      self.is_called = True
+    if error is None:
+      self._invoke_success(metadata)
+    else:
+      self._invoke_failure(error)
+
+  def notify_failure(self, error):
+    with self.is_called_lock:
+      if not self.is_called:
+        self.error = error
+
+
+class _WrappedPlugin(object):
+
+  def __init__(self, plugin):
+    self.plugin = plugin
+
+  def __call__(self, context, cygrpc_callback):
+    wrapped_cygrpc_callback = _WrappedCygrpcCallback(cygrpc_callback)
+    wrapped_context = _implementations.AuthMetadataContext(context.service_url,
+                                                           context.method_name)
+    try:
+      self.plugin(
+          wrapped_context,
+          _implementations.AuthMetadataPluginCallback(wrapped_cygrpc_callback))
+    except Exception as error:
+      wrapped_cygrpc_callback.notify_failure(error)
+      raise
+
+
+def call_credentials_metadata_plugin(plugin, name):
+  """
+  Args:
+    plugin: A callable accepting a _types.AuthMetadataContext
+      object and a callback (itself accepting a list of metadata key/value
+      2-tuples and a None-able exception value). The callback must be eventually
+      called, but need not be called in plugin's invocation.
+      plugin's invocation must be non-blocking.
+  """
+  return cygrpc.call_credentials_metadata_plugin(
+      cygrpc.CredentialsMetadataPlugin(_WrappedPlugin(plugin), name))
 
 
 class CompletionQueue(_types.CompletionQueue):
 
   def __init__(self):
-    self.completion_queue = _c.CompletionQueue()
+    self.completion_queue = cygrpc.CompletionQueue()
 
   def next(self, deadline=float('+inf')):
-    raw_event = self.completion_queue.next(deadline)
-    if raw_event is None:
+    raw_event = self.completion_queue.poll(cygrpc.Timespec(deadline))
+    if raw_event.type == cygrpc.CompletionType.queue_timeout:
       return None
-    event = _types.Event(*raw_event)
-    if event.call is not None:
-      event = event._replace(call=Call(event.call))
-    if event.call_details is not None:
-      event = event._replace(call_details=_types.CallDetails(*event.call_details))
-    if event.results is not None:
-      new_results = [_types.OpResult(*r) for r in event.results]
-      new_results = [r if r.status is None else r._replace(status=_types.Status(_types.StatusCode(r.status[0]), r.status[1])) for r in new_results]
-      event = event._replace(results=new_results)
-    return event
+    event_type = raw_event.type
+    event_tag = raw_event.tag
+    event_call = Call(raw_event.operation_call)
+    if raw_event.request_call_details:
+      event_call_details = _types.CallDetails(
+          raw_event.request_call_details.method,
+          raw_event.request_call_details.host,
+          float(raw_event.request_call_details.deadline))
+    else:
+      event_call_details = None
+    event_success = raw_event.success
+    event_results = []
+    if raw_event.is_new_request:
+      event_results.append(_types.OpResult(
+          _types.OpType.RECV_INITIAL_METADATA, raw_event.request_metadata,
+          None, None, None, None))
+    else:
+      if raw_event.batch_operations:
+        for operation in raw_event.batch_operations:
+          result_type = operation.type
+          result_initial_metadata = operation.received_metadata_or_none
+          result_trailing_metadata = operation.received_metadata_or_none
+          result_message = operation.received_message_or_none
+          if result_message is not None:
+            result_message = result_message.bytes()
+          result_cancelled = operation.received_cancelled_or_none
+          if operation.has_status:
+            result_status = _types.Status(
+                operation.received_status_code_or_none,
+                operation.received_status_details_or_none)
+          else:
+            result_status = None
+          event_results.append(
+              _types.OpResult(result_type, result_initial_metadata,
+                              result_trailing_metadata, result_message,
+                              result_status, result_cancelled))
+    return _types.Event(event_type, event_tag, event_call, event_call_details,
+                        event_results, event_success)
 
   def shutdown(self):
     self.completion_queue.shutdown()
@@ -68,7 +189,36 @@ class Call(_types.Call):
     self.call = call
 
   def start_batch(self, ops, tag):
-    return self.call.start_batch(ops, tag)
+    translated_ops = []
+    for op in ops:
+      if op.type == _types.OpType.SEND_INITIAL_METADATA:
+        translated_op = cygrpc.operation_send_initial_metadata(
+            cygrpc.Metadata(
+                cygrpc.Metadatum(key, value)
+                for key, value in op.initial_metadata))
+      elif op.type == _types.OpType.SEND_MESSAGE:
+        translated_op = cygrpc.operation_send_message(op.message)
+      elif op.type == _types.OpType.SEND_CLOSE_FROM_CLIENT:
+        translated_op = cygrpc.operation_send_close_from_client()
+      elif op.type == _types.OpType.SEND_STATUS_FROM_SERVER:
+        translated_op = cygrpc.operation_send_status_from_server(
+            cygrpc.Metadata(
+                cygrpc.Metadatum(key, value)
+                for key, value in op.trailing_metadata),
+            op.status.code,
+            op.status.details)
+      elif op.type == _types.OpType.RECV_INITIAL_METADATA:
+        translated_op = cygrpc.operation_receive_initial_metadata()
+      elif op.type == _types.OpType.RECV_MESSAGE:
+        translated_op = cygrpc.operation_receive_message()
+      elif op.type == _types.OpType.RECV_STATUS_ON_CLIENT:
+        translated_op = cygrpc.operation_receive_status_on_client()
+      elif op.type == _types.OpType.RECV_CLOSE_ON_SERVER:
+        translated_op = cygrpc.operation_receive_close_on_server()
+      else:
+        raise ValueError('unexpected operation type {}'.format(op.type))
+      translated_ops.append(translated_op)
+    return self.call.start_batch(cygrpc.Operations(translated_ops), tag)
 
   def cancel(self, code=None, details=None):
     if code is None and details is None:
@@ -86,14 +236,20 @@ class Call(_types.Call):
 class Channel(_types.Channel):
 
   def __init__(self, target, args, creds=None):
-    args = list(args) + [(_c.PRIMARY_USER_AGENT_KEY, _USER_AGENT)]
+    args = list(args) + [
+        (cygrpc.ChannelArgKey.primary_user_agent_string, _USER_AGENT)]
+    args = cygrpc.ChannelArgs(
+        cygrpc.ChannelArg(key, value) for key, value in args)
     if creds is None:
-      self.channel = _c.Channel(target, args)
+      self.channel = cygrpc.Channel(target, args)
     else:
-      self.channel = _c.Channel(target, args, creds)
+      self.channel = cygrpc.Channel(target, args, creds)
 
   def create_call(self, completion_queue, method, host, deadline=None):
-    return Call(self.channel.create_call(completion_queue.completion_queue, method, host, deadline))
+    internal_call = self.channel.create_call(
+        None, 0, completion_queue.completion_queue, method, host,
+        cygrpc.Timespec(deadline))
+    return Call(internal_call)
 
   def check_connectivity_state(self, try_to_connect):
     return self.channel.check_connectivity_state(try_to_connect)
@@ -101,7 +257,8 @@ class Channel(_types.Channel):
   def watch_connectivity_state(self, last_observed_state, deadline,
                                completion_queue, tag):
     self.channel.watch_connectivity_state(
-        last_observed_state, deadline, completion_queue.completion_queue, tag)
+        last_observed_state, cygrpc.Timespec(deadline),
+        completion_queue.completion_queue, tag)
 
   def target(self):
     return self.channel.target()
@@ -112,7 +269,11 @@ _NO_TAG = object()
 class Server(_types.Server):
 
   def __init__(self, completion_queue, args):
-    self.server = _c.Server(completion_queue.completion_queue, args)
+    args = cygrpc.ChannelArgs(
+        cygrpc.ChannelArg(key, value) for key, value in args)
+    self.server = cygrpc.Server(args)
+    self.server.register_completion_queue(completion_queue.completion_queue)
+    self.server_queue = completion_queue
 
   def add_http2_port(self, addr, creds=None):
     if creds is None:
@@ -124,10 +285,11 @@ class Server(_types.Server):
     return self.server.start()
 
   def shutdown(self, tag=None):
-    return self.server.shutdown(tag)
+    return self.server.shutdown(self.server_queue.completion_queue, tag)
 
   def request_call(self, completion_queue, tag):
-    return self.server.request_call(completion_queue.completion_queue, tag)
+    return self.server.request_call(completion_queue.completion_queue,
+                                    self.server_queue.completion_queue, tag)
 
   def cancel_all_calls(self):
     return self.server.cancel_all_calls()
diff --git a/src/python/grpcio/grpc/_adapter/_types.py b/src/python/grpcio/grpc/_adapter/_types.py
index ca0fa066bc..3d5ab33d00 100644
--- a/src/python/grpcio/grpc/_adapter/_types.py
+++ b/src/python/grpcio/grpc/_adapter/_types.py
@@ -31,6 +31,8 @@ import abc
 import collections
 import enum
 
+from grpc._cython import cygrpc
+
 
 class GrpcChannelArgumentKeys(enum.Enum):
   """Mirrors keys used in grpc_channel_args for GRPC-specific arguments."""
@@ -40,77 +42,77 @@ class GrpcChannelArgumentKeys(enum.Enum):
 @enum.unique
 class CallError(enum.IntEnum):
   """Mirrors grpc_call_error in the C core."""
-  OK                        = 0
-  ERROR                     = 1
-  ERROR_NOT_ON_SERVER       = 2
-  ERROR_NOT_ON_CLIENT       = 3
-  ERROR_ALREADY_ACCEPTED    = 4
-  ERROR_ALREADY_INVOKED     = 5
-  ERROR_NOT_INVOKED         = 6
-  ERROR_ALREADY_FINISHED    = 7
-  ERROR_TOO_MANY_OPERATIONS = 8
-  ERROR_INVALID_FLAGS       = 9
-  ERROR_INVALID_METADATA    = 10
+  OK                        = cygrpc.CallError.ok
+  ERROR                     = cygrpc.CallError.error
+  ERROR_NOT_ON_SERVER       = cygrpc.CallError.not_on_server
+  ERROR_NOT_ON_CLIENT       = cygrpc.CallError.not_on_client
+  ERROR_ALREADY_ACCEPTED    = cygrpc.CallError.already_accepted
+  ERROR_ALREADY_INVOKED     = cygrpc.CallError.already_invoked
+  ERROR_NOT_INVOKED         = cygrpc.CallError.not_invoked
+  ERROR_ALREADY_FINISHED    = cygrpc.CallError.already_finished
+  ERROR_TOO_MANY_OPERATIONS = cygrpc.CallError.too_many_operations
+  ERROR_INVALID_FLAGS       = cygrpc.CallError.invalid_flags
+  ERROR_INVALID_METADATA    = cygrpc.CallError.invalid_metadata
 
 
 @enum.unique
 class StatusCode(enum.IntEnum):
   """Mirrors grpc_status_code in the C core."""
-  OK                  = 0
-  CANCELLED           = 1
-  UNKNOWN             = 2
-  INVALID_ARGUMENT    = 3
-  DEADLINE_EXCEEDED   = 4
-  NOT_FOUND           = 5
-  ALREADY_EXISTS      = 6
-  PERMISSION_DENIED   = 7
-  RESOURCE_EXHAUSTED  = 8
-  FAILED_PRECONDITION = 9
-  ABORTED             = 10
-  OUT_OF_RANGE        = 11
-  UNIMPLEMENTED       = 12
-  INTERNAL            = 13
-  UNAVAILABLE         = 14
-  DATA_LOSS           = 15
-  UNAUTHENTICATED     = 16
+  OK                  = cygrpc.StatusCode.ok
+  CANCELLED           = cygrpc.StatusCode.cancelled
+  UNKNOWN             = cygrpc.StatusCode.unknown
+  INVALID_ARGUMENT    = cygrpc.StatusCode.invalid_argument
+  DEADLINE_EXCEEDED   = cygrpc.StatusCode.deadline_exceeded
+  NOT_FOUND           = cygrpc.StatusCode.not_found
+  ALREADY_EXISTS      = cygrpc.StatusCode.already_exists
+  PERMISSION_DENIED   = cygrpc.StatusCode.permission_denied
+  RESOURCE_EXHAUSTED  = cygrpc.StatusCode.resource_exhausted
+  FAILED_PRECONDITION = cygrpc.StatusCode.failed_precondition
+  ABORTED             = cygrpc.StatusCode.aborted
+  OUT_OF_RANGE        = cygrpc.StatusCode.out_of_range
+  UNIMPLEMENTED       = cygrpc.StatusCode.unimplemented
+  INTERNAL            = cygrpc.StatusCode.internal
+  UNAVAILABLE         = cygrpc.StatusCode.unavailable
+  DATA_LOSS           = cygrpc.StatusCode.data_loss
+  UNAUTHENTICATED     = cygrpc.StatusCode.unauthenticated
 
 
 @enum.unique
 class OpWriteFlags(enum.IntEnum):
   """Mirrors defined write-flag constants in the C core."""
-  WRITE_BUFFER_HINT = 1
-  WRITE_NO_COMPRESS = 2
+  WRITE_BUFFER_HINT = cygrpc.WriteFlag.buffer_hint
+  WRITE_NO_COMPRESS = cygrpc.WriteFlag.no_compress
 
 
 @enum.unique
 class OpType(enum.IntEnum):
   """Mirrors grpc_op_type in the C core."""
-  SEND_INITIAL_METADATA   = 0
-  SEND_MESSAGE            = 1
-  SEND_CLOSE_FROM_CLIENT  = 2
-  SEND_STATUS_FROM_SERVER = 3
-  RECV_INITIAL_METADATA   = 4
-  RECV_MESSAGE            = 5
-  RECV_STATUS_ON_CLIENT   = 6
-  RECV_CLOSE_ON_SERVER    = 7
+  SEND_INITIAL_METADATA   = cygrpc.OperationType.send_initial_metadata
+  SEND_MESSAGE            = cygrpc.OperationType.send_message
+  SEND_CLOSE_FROM_CLIENT  = cygrpc.OperationType.send_close_from_client
+  SEND_STATUS_FROM_SERVER = cygrpc.OperationType.send_status_from_server
+  RECV_INITIAL_METADATA   = cygrpc.OperationType.receive_initial_metadata
+  RECV_MESSAGE            = cygrpc.OperationType.receive_message
+  RECV_STATUS_ON_CLIENT   = cygrpc.OperationType.receive_status_on_client
+  RECV_CLOSE_ON_SERVER    = cygrpc.OperationType.receive_close_on_server
 
 
 @enum.unique
 class EventType(enum.IntEnum):
   """Mirrors grpc_completion_type in the C core."""
-  QUEUE_SHUTDOWN = 0
-  QUEUE_TIMEOUT  = 1  # if seen on the Python side, something went horridly wrong
-  OP_COMPLETE    = 2
+  QUEUE_SHUTDOWN = cygrpc.CompletionType.queue_shutdown
+  QUEUE_TIMEOUT  = cygrpc.CompletionType.queue_timeout
+  OP_COMPLETE    = cygrpc.CompletionType.operation_complete
 
 
 @enum.unique
 class ConnectivityState(enum.IntEnum):
   """Mirrors grpc_connectivity_state in the C core."""
-  IDLE              = 0
-  CONNECTING        = 1
-  READY             = 2
-  TRANSIENT_FAILURE = 3
-  FATAL_FAILURE     = 4
+  IDLE              = cygrpc.ConnectivityState.idle
+  CONNECTING        = cygrpc.ConnectivityState.connecting
+  READY             = cygrpc.ConnectivityState.ready
+  TRANSIENT_FAILURE = cygrpc.ConnectivityState.transient_failure
+  FATAL_FAILURE     = cygrpc.ConnectivityState.fatal_failure
 
 
 class Status(collections.namedtuple(
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/call.pyx b/src/python/grpcio/grpc/_cython/_cygrpc/call.pyx
index 51c4668138..1c07f9f4f4 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/call.pyx
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/call.pyx
@@ -53,24 +53,24 @@ cdef class Call:
         self.c_call, cy_operations.c_ops, cy_operations.c_nops,
         <cpython.PyObject *>operation_tag, NULL)
 
-  def cancel(self,
-             grpc.grpc_status_code error_code=grpc.GRPC_STATUS__DO_NOT_USE,
-             details=None):
+  def cancel(
+      self, grpc.grpc_status_code error_code=grpc.GRPC_STATUS__DO_NOT_USE,
+      details=None):
     if not self.is_valid:
       raise ValueError("invalid call object cannot be used from Python")
     if (details is None) != (error_code == grpc.GRPC_STATUS__DO_NOT_USE):
       raise ValueError("if error_code is specified, so must details "
                        "(and vice-versa)")
-    if isinstance(details, bytes):
-      pass
-    elif isinstance(details, basestring):
-      details = details.encode()
-    else:
-      raise TypeError("expected details to be str or bytes")
     if error_code != grpc.GRPC_STATUS__DO_NOT_USE:
+      if isinstance(details, bytes):
+        pass
+      elif isinstance(details, basestring):
+        details = details.encode()
+      else:
+        raise TypeError("expected details to be str or bytes")
       self.references.append(details)
-      return grpc.grpc_call_cancel_with_status(self.c_call, error_code, details,
-                                               NULL)
+      return grpc.grpc_call_cancel_with_status(
+          self.c_call, error_code, details, NULL)
     else:
       return grpc.grpc_call_cancel(self.c_call, NULL)
 
@@ -79,6 +79,12 @@ cdef class Call:
     return grpc.grpc_call_set_credentials(
         self.c_call, call_credentials.c_credentials)
 
+  def peer(self):
+    cdef char *peer = grpc.grpc_call_get_peer(self.c_call)
+    result = <bytes>peer
+    grpc.gpr_free(peer)
+    return result
+
   def __dealloc__(self):
     if self.c_call != NULL:
       grpc.grpc_call_destroy(self.c_call)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx b/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx
index e25db3e2a4..a944a83576 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx
@@ -27,6 +27,8 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+cimport cpython
+
 from grpc._cython._cygrpc cimport call
 from grpc._cython._cygrpc cimport completion_queue
 from grpc._cython._cygrpc cimport credentials
@@ -70,12 +72,16 @@ cdef class Channel:
       method = method.encode()
     else:
       raise TypeError("expected method to be str or bytes")
-    if isinstance(host, bytes):
+    cdef char *host_c_string = NULL
+    if host is None:
       pass
+    elif isinstance(host, bytes):
+      host_c_string = host
     elif isinstance(host, basestring):
       host = host.encode()
+      host_c_string = host
     else:
-      raise TypeError("expected host to be str or bytes")
+      raise TypeError("expected host to be str, bytes, or None")
     cdef call.Call operation_call = call.Call()
     operation_call.references = [self, method, host, queue]
     cdef grpc.grpc_call *parent_call = NULL
@@ -83,10 +89,29 @@ cdef class Channel:
       parent_call = parent.c_call
     operation_call.c_call = grpc.grpc_channel_create_call(
         self.c_channel, parent_call, flags,
-        queue.c_completion_queue, method, host, deadline.c_time,
+        queue.c_completion_queue, method, host_c_string, deadline.c_time,
         NULL)
     return operation_call
 
+  def check_connectivity_state(self, bint try_to_connect):
+    return grpc.grpc_channel_check_connectivity_state(self.c_channel,
+                                                      try_to_connect)
+
+  def watch_connectivity_state(
+      self, last_observed_state, records.Timespec deadline not None,
+      completion_queue.CompletionQueue queue not None, tag):
+    cdef records.OperationTag operation_tag = records.OperationTag(tag)
+    cpython.Py_INCREF(operation_tag)
+    grpc.grpc_channel_watch_connectivity_state(
+        self.c_channel, last_observed_state, deadline.c_time,
+        queue.c_completion_queue, <cpython.PyObject *>operation_tag)
+
+  def target(self):
+    cdef char * target = grpc.grpc_channel_get_target(self.c_channel)
+    result = <bytes>target
+    grpc.gpr_free(target)
+    return result
+
   def __dealloc__(self):
     if self.c_channel != NULL:
       grpc.grpc_channel_destroy(self.c_channel)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx
index a7a265eab7..2cf49707b4 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/completion_queue.pyx
@@ -62,6 +62,8 @@ cdef class CompletionQueue:
     cdef grpc.grpc_event event
 
     # Poll within a critical section
+    # TODO consider making queue polling contention a hard error to enable
+    # easier bug discovery
     with self.poll_condition:
       while self.is_polling:
         self.poll_condition.wait(float(deadline) - time.time())
@@ -74,10 +76,12 @@ cdef class CompletionQueue:
       self.poll_condition.notify()
 
     if event.type == grpc.GRPC_QUEUE_TIMEOUT:
-      return records.Event(event.type, False, None, None, None, None, None)
+      return records.Event(
+          event.type, False, None, None, None, None, False, None)
     elif event.type == grpc.GRPC_QUEUE_SHUTDOWN:
       self.is_shutdown = True
-      return records.Event(event.type, True, None, None, None, None, None)
+      return records.Event(
+          event.type, True, None, None, None, None, False, None)
     else:
       if event.tag != NULL:
         tag = <records.OperationTag>event.tag
@@ -97,7 +101,8 @@ cdef class CompletionQueue:
           operation_call.references.extend(tag.references)
       return records.Event(
           event.type, event.success, user_tag, operation_call,
-          request_call_details, request_metadata, batch_operations)
+          request_call_details, request_metadata, tag.is_new_request,
+          batch_operations)
 
   def shutdown(self):
     grpc.grpc_completion_queue_shutdown(self.c_completion_queue)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd
index 7a9fa7b76d..db9f8ddec9 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pxd
@@ -27,7 +27,10 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+cimport cpython
+
 from grpc._cython._cygrpc cimport grpc
+from grpc._cython._cygrpc cimport records
 
 
 cdef class ChannelCredentials:
@@ -49,3 +52,23 @@ cdef class ServerCredentials:
   cdef grpc.grpc_ssl_pem_key_cert_pair *c_ssl_pem_key_cert_pairs
   cdef size_t c_ssl_pem_key_cert_pairs_count
   cdef list references
+
+
+cdef class CredentialsMetadataPlugin:
+
+  cdef object plugin_callback
+  cdef str plugin_name
+
+  cdef grpc.grpc_metadata_credentials_plugin make_c_plugin(self)
+
+
+cdef class AuthMetadataContext:
+
+  cdef grpc.grpc_auth_metadata_context context
+
+
+cdef void plugin_get_metadata(
+    void *state, grpc.grpc_auth_metadata_context context,
+    grpc.grpc_credentials_plugin_metadata_cb cb, void *user_data) with gil
+
+cdef void plugin_destroy_c_plugin_state(void *state)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx
index e9836fec2c..a968894967 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx
@@ -27,6 +27,8 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+cimport cpython
+
 from grpc._cython._cygrpc cimport grpc
 from grpc._cython._cygrpc cimport records
 
@@ -71,19 +73,80 @@ cdef class ServerCredentials:
 
   def __cinit__(self):
     self.c_credentials = NULL
+    self.references = []
 
   def __dealloc__(self):
     if self.c_credentials != NULL:
       grpc.grpc_server_credentials_release(self.c_credentials)
 
 
+cdef class CredentialsMetadataPlugin:
+
+  def __cinit__(self, object plugin_callback, str name):
+    """
+    Args:
+      plugin_callback (callable): Callback accepting a service URL (str/bytes)
+        and callback object (accepting a records.Metadata,
+        grpc.grpc_status_code, and a str/bytes error message). This argument
+        when called should be non-blocking and eventually call the callback
+        object with the appropriate status code/details and metadata (if
+        successful).
+      name (str): Plugin name.
+    """
+    if not callable(plugin_callback):
+      raise ValueError('expected callable plugin_callback')
+    self.plugin_callback = plugin_callback
+    self.plugin_name = name
+
+  @staticmethod
+  cdef grpc.grpc_metadata_credentials_plugin make_c_plugin(self):
+    cdef grpc.grpc_metadata_credentials_plugin result
+    result.get_metadata = plugin_get_metadata
+    result.destroy = plugin_destroy_c_plugin_state
+    result.state = <void *>self
+    result.type = self.plugin_name
+    cpython.Py_INCREF(self)
+    return result
+
+
+cdef class AuthMetadataContext:
+
+  def __cinit__(self):
+    self.context.service_url = NULL
+    self.context.method_name = NULL
+
+  @property
+  def service_url(self):
+    return self.context.service_url
+
+  @property
+  def method_name(self):
+    return self.context.method_name
+
+
+cdef void plugin_get_metadata(
+    void *state, grpc.grpc_auth_metadata_context context,
+    grpc.grpc_credentials_plugin_metadata_cb cb, void *user_data) with gil:
+  def python_callback(
+      records.Metadata metadata, grpc.grpc_status_code status,
+      const char *error_details):
+    cb(user_data, metadata.c_metadata_array.metadata,
+       metadata.c_metadata_array.count, status, error_details)
+  cdef CredentialsMetadataPlugin self = <CredentialsMetadataPlugin>state
+  cdef AuthMetadataContext cy_context = AuthMetadataContext()
+  cy_context.context = context
+  self.plugin_callback(cy_context, python_callback)
+
+cdef void plugin_destroy_c_plugin_state(void *state):
+  cpython.Py_DECREF(<CredentialsMetadataPlugin>state)
+
 def channel_credentials_google_default():
   cdef ChannelCredentials credentials = ChannelCredentials();
   credentials.c_credentials = grpc.grpc_google_default_credentials_create()
   return credentials
 
 def channel_credentials_ssl(pem_root_certificates,
-                           records.SslPemKeyCertPair ssl_pem_key_cert_pair):
+                            records.SslPemKeyCertPair ssl_pem_key_cert_pair):
   if pem_root_certificates is None:
     pass
   elif isinstance(pem_root_certificates, bytes):
@@ -104,6 +167,7 @@ def channel_credentials_ssl(pem_root_certificates,
   else:
     credentials.c_credentials = grpc.grpc_ssl_credentials_create(
       c_pem_root_certificates, NULL, NULL)
+  return credentials
 
 def channel_credentials_composite(
     ChannelCredentials credentials_1 not None,
@@ -135,7 +199,6 @@ def call_credentials_google_compute_engine():
       grpc.grpc_google_compute_engine_credentials_create(NULL))
   return credentials
 
-#TODO rename to something like client_credentials_service_account_jwt_access.
 def call_credentials_service_account_jwt_access(
     json_key, records.Timespec token_lifetime not None):
   if isinstance(json_key, bytes):
@@ -184,14 +247,25 @@ def call_credentials_google_iam(authorization_token, authority_selector):
   credentials.references.append(authority_selector)
   return credentials
 
+def call_credentials_metadata_plugin(CredentialsMetadataPlugin plugin):
+  cdef CallCredentials credentials = CallCredentials()
+  credentials.c_credentials = (
+      grpc.grpc_metadata_credentials_create_from_plugin(plugin.make_c_plugin(),
+                                                        NULL))
+  # TODO(atash): the following held reference is *probably* never necessary
+  credentials.references.append(plugin)
+  return credentials
+
 def server_credentials_ssl(pem_root_certs, pem_key_cert_pairs,
                            bint force_client_auth):
+  cdef char *c_pem_root_certs = NULL
   if pem_root_certs is None:
     pass
   elif isinstance(pem_root_certs, bytes):
-    pass
+    c_pem_root_certs = pem_root_certs
   elif isinstance(pem_root_certs, basestring):
     pem_root_certs = pem_root_certs.encode()
+    c_pem_root_certs = pem_root_certs
   else:
     raise TypeError("expected pem_root_certs to be str or bytes")
   pem_key_cert_pairs = list(pem_key_cert_pairs)
@@ -212,7 +286,7 @@ def server_credentials_ssl(pem_root_certs, pem_key_cert_pairs,
     credentials.c_ssl_pem_key_cert_pairs[i] = (
         (<records.SslPemKeyCertPair>pem_key_cert_pairs[i]).c_pair)
   credentials.c_credentials = grpc.grpc_ssl_server_credentials_create(
-      pem_root_certs, credentials.c_ssl_pem_key_cert_pairs,
+      c_pem_root_certs, credentials.c_ssl_pem_key_cert_pairs,
       credentials.c_ssl_pem_key_cert_pairs_count, force_client_auth, NULL)
   return credentials
 
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxd b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxd
index 36aea81a6c..10c948cd0a 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxd
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxd
@@ -132,6 +132,20 @@ cdef extern from "grpc/byte_buffer.h":
 
 cdef extern from "grpc/grpc.h":
 
+  const char *GRPC_ARG_PRIMARY_USER_AGENT_STRING
+  const char *GRPC_ARG_ENABLE_CENSUS
+  const char *GRPC_ARG_MAX_CONCURRENT_STREAMS
+  const char *GRPC_ARG_MAX_MESSAGE_LENGTH
+  const char *GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER
+  const char *GRPC_ARG_DEFAULT_AUTHORITY
+  const char *GRPC_ARG_PRIMARY_USER_AGENT_STRING
+  const char *GRPC_ARG_SECONDARY_USER_AGENT_STRING
+  const char *GRPC_SSL_TARGET_NAME_OVERRIDE_ARG
+
+  const int GRPC_WRITE_BUFFER_HINT
+  const int GRPC_WRITE_NO_COMPRESS
+  const int GRPC_WRITE_USED_MASK
+
   ctypedef struct grpc_completion_queue:
     # We don't care about the internals (and in fact don't know them)
     pass
@@ -149,9 +163,9 @@ cdef extern from "grpc/grpc.h":
     pass
 
   ctypedef enum grpc_arg_type:
-    grpc_arg_string "GRPC_ARG_STRING"
-    grpc_arg_integer "GRPC_ARG_INTEGER"
-    grpc_arg_pointer "GRPC_ARG_POINTER"
+    GRPC_ARG_STRING
+    GRPC_ARG_INTEGER
+    GRPC_ARG_POINTER
 
   ctypedef struct grpc_arg_value_pointer:
     void *address "p"
@@ -185,6 +199,13 @@ cdef extern from "grpc/grpc.h":
     GRPC_CALL_ERROR_INVALID_FLAGS
     GRPC_CALL_ERROR_INVALID_METADATA
 
+  ctypedef enum grpc_connectivity_state:
+    GRPC_CHANNEL_IDLE
+    GRPC_CHANNEL_CONNECTING
+    GRPC_CHANNEL_READY
+    GRPC_CHANNEL_TRANSIENT_FAILURE
+    GRPC_CHANNEL_FATAL_FAILURE
+
   ctypedef struct grpc_metadata:
     const char *key
     const char *value
@@ -279,9 +300,9 @@ cdef extern from "grpc/grpc.h":
                                                grpc_status_code status,
                                                const char *description,
                                                void *reserved)
+  char *grpc_call_get_peer(grpc_call *call)
   void grpc_call_destroy(grpc_call *call)
 
-
   grpc_channel *grpc_insecure_channel_create(const char *target,
                                              const grpc_channel_args *args,
                                              void *reserved)
@@ -291,6 +312,12 @@ cdef extern from "grpc/grpc.h":
                                       grpc_completion_queue *completion_queue,
                                       const char *method, const char *host,
                                       gpr_timespec deadline, void *reserved)
+  grpc_connectivity_state grpc_channel_check_connectivity_state(
+      grpc_channel *channel, int try_to_connect)
+  void grpc_channel_watch_connectivity_state(
+      grpc_channel *channel, grpc_connectivity_state last_observed_state,
+      gpr_timespec deadline, grpc_completion_queue *cq, void *tag)
+  char *grpc_channel_get_target(grpc_channel *channel)
   void grpc_channel_destroy(grpc_channel *channel)
 
   grpc_server *grpc_server_create(const grpc_channel_args *args, void *reserved)
@@ -367,3 +394,27 @@ cdef extern from "grpc/grpc_security.h":
 
   grpc_call_error grpc_call_set_credentials(grpc_call *call,
                                             grpc_call_credentials *creds)
+
+  ctypedef struct grpc_auth_context:
+    # We don't care about the internals (and in fact don't know them)
+    pass
+
+  ctypedef struct grpc_auth_metadata_context:
+    const char *service_url
+    const char *method_name
+    const grpc_auth_context *channel_auth_context
+
+  ctypedef void (*grpc_credentials_plugin_metadata_cb)(
+      void *user_data, const grpc_metadata *creds_md, size_t num_creds_md,
+      grpc_status_code status, const char *error_details)
+
+  ctypedef struct grpc_metadata_credentials_plugin:
+    void (*get_metadata)(
+        void *state, grpc_auth_metadata_context context,
+        grpc_credentials_plugin_metadata_cb cb, void *user_data)
+    void (*destroy)(void *state)
+    void *state
+    const char *type
+
+  grpc_call_credentials *grpc_metadata_credentials_create_from_plugin(
+      grpc_metadata_credentials_plugin plugin, void *reserved)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd b/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd
index 9ee487882a..4c844e4cb6 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/records.pxd
@@ -66,6 +66,7 @@ cdef class Event:
   cdef readonly call.Call operation_call
 
   # For Server.request_call
+  cdef readonly bint is_new_request
   cdef readonly CallDetails request_call_details
   cdef readonly Metadata request_metadata
 
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx
index 8edee09c2d..79a7f8f563 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx
@@ -32,6 +32,30 @@ from grpc._cython._cygrpc cimport call
 from grpc._cython._cygrpc cimport server
 
 
+class ConnectivityState:
+  idle = grpc.GRPC_CHANNEL_IDLE
+  connecting = grpc.GRPC_CHANNEL_CONNECTING
+  ready = grpc.GRPC_CHANNEL_READY
+  transient_failure = grpc.GRPC_CHANNEL_TRANSIENT_FAILURE
+  fatal_failure = grpc.GRPC_CHANNEL_FATAL_FAILURE
+
+
+class ChannelArgKey:
+  enable_census = grpc.GRPC_ARG_ENABLE_CENSUS
+  max_concurrent_streams = grpc.GRPC_ARG_MAX_CONCURRENT_STREAMS
+  max_message_length = grpc.GRPC_ARG_MAX_MESSAGE_LENGTH
+  http2_initial_sequence_number = grpc.GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER
+  default_authority = grpc.GRPC_ARG_DEFAULT_AUTHORITY
+  primary_user_agent_string = grpc.GRPC_ARG_PRIMARY_USER_AGENT_STRING
+  secondary_user_agent_string = grpc.GRPC_ARG_SECONDARY_USER_AGENT_STRING
+  ssl_target_name_override = grpc.GRPC_SSL_TARGET_NAME_OVERRIDE_ARG
+
+
+class WriteFlag:
+  buffer_hint = grpc.GRPC_WRITE_BUFFER_HINT
+  no_compress = grpc.GRPC_WRITE_NO_COMPRESS
+
+
 class StatusCode:
   ok = grpc.GRPC_STATUS_OK
   cancelled = grpc.GRPC_STATUS_CANCELLED
@@ -88,7 +112,10 @@ cdef class Timespec:
   def __cinit__(self, time):
     if time is None:
       self.c_time = grpc.gpr_now(grpc.GPR_CLOCK_REALTIME)
-    elif isinstance(time, float):
+      return
+    if isinstance(time, int):
+      time = float(time)
+    if isinstance(time, float):
       if time == float("+inf"):
         self.c_time = grpc.gpr_inf_future(grpc.GPR_CLOCK_REALTIME)
       elif time == float("-inf"):
@@ -97,8 +124,11 @@ cdef class Timespec:
         self.c_time.seconds = time
         self.c_time.nanoseconds = (time - float(self.c_time.seconds)) * 1e9
         self.c_time.clock_type = grpc.GPR_CLOCK_REALTIME
+    elif isinstance(time, Timespec):
+      self.c_time = (<Timespec>time).c_time
     else:
-      raise TypeError("expected time to be float")
+      raise TypeError("expected time to be float, int, or Timespec, not {}"
+                          .format(type(time)))
 
   @property
   def seconds(self):
@@ -166,6 +196,7 @@ cdef class Event:
                 object tag, call.Call operation_call,
                 CallDetails request_call_details,
                 Metadata request_metadata,
+                bint is_new_request,
                 Operations batch_operations):
     self.type = type
     self.success = success
@@ -174,6 +205,7 @@ cdef class Event:
     self.request_call_details = request_call_details
     self.request_metadata = request_metadata
     self.batch_operations = batch_operations
+    self.is_new_request = is_new_request
 
 
 cdef class ByteBuffer:
@@ -186,8 +218,14 @@ cdef class ByteBuffer:
       pass
     elif isinstance(data, basestring):
       data = data.encode()
+    elif isinstance(data, ByteBuffer):
+      data = (<ByteBuffer>data).bytes()
+      if data is None:
+        self.c_byte_buffer = NULL
+        return
     else:
-      raise TypeError("expected value to be of type str or bytes")
+      raise TypeError("expected value to be of type str, bytes, or "
+                      "ByteBuffer, not {}".format(type(data)))
 
     cdef char *c_data = data
     data_slice = grpc.gpr_slice_from_copied_buffer(c_data, len(data))
@@ -410,12 +448,22 @@ cdef class Operation:
     return self.c_op.type
 
   @property
+  def has_status(self):
+    return self.c_op.type == grpc.GRPC_OP_RECV_STATUS_ON_CLIENT
+
+  @property
   def received_message(self):
     if self.c_op.type != grpc.GRPC_OP_RECV_MESSAGE:
       raise TypeError("self must be an operation receiving a message")
     return self._received_message
 
   @property
+  def received_message_or_none(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_MESSAGE:
+      return None
+    return self._received_message
+
+  @property
   def received_metadata(self):
     if (self.c_op.type != grpc.GRPC_OP_RECV_INITIAL_METADATA and
         self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT):
@@ -423,12 +471,25 @@ cdef class Operation:
     return self._received_metadata
 
   @property
+  def received_metadata_or_none(self):
+    if (self.c_op.type != grpc.GRPC_OP_RECV_INITIAL_METADATA and
+        self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT):
+      return None
+    return self._received_metadata
+
+  @property
   def received_status_code(self):
     if self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT:
       raise TypeError("self must be an operation receiving a status code")
     return self._received_status_code
 
   @property
+  def received_status_code_or_none(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT:
+      return None
+    return self._received_status_code
+
+  @property
   def received_status_details(self):
     if self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT:
       raise TypeError("self must be an operation receiving status details")
@@ -438,12 +499,27 @@ cdef class Operation:
       return None
 
   @property
+  def received_status_details_or_none(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_STATUS_ON_CLIENT:
+      return None
+    if self._received_status_details:
+      return self._received_status_details
+    else:
+      return None
+
+  @property
   def received_cancelled(self):
     if self.c_op.type != grpc.GRPC_OP_RECV_CLOSE_ON_SERVER:
       raise TypeError("self must be an operation receiving cancellation "
                       "information")
     return False if self._received_cancelled == 0 else True
 
+  @property
+  def received_cancelled_or_none(self):
+    if self.c_op.type != grpc.GRPC_OP_RECV_CLOSE_ON_SERVER:
+      return None
+    return False if self._received_cancelled == 0 else True
+
   def __dealloc__(self):
     # We *almost* don't need to do anything; most of the objects are handled by
     # Python. The remaining one(s) are primitive fields filled in by GRPC core.
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/server.pyx b/src/python/grpcio/grpc/_cython/_cygrpc/server.pyx
index 6d20d2910c..46df8bf77f 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/server.pyx
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/server.pyx
@@ -132,7 +132,7 @@ cdef class Server:
 
   def cancel_all_calls(self):
     if not self.is_shutting_down:
-      raise ValueError("the server must be shutting down to cancel all calls")
+      raise RuntimeError("the server must be shutting down to cancel all calls")
     elif self.is_shutdown:
       return
     else:
diff --git a/src/python/grpcio/grpc/_cython/adapter_low.py b/src/python/grpcio/grpc/_cython/adapter_low.py
deleted file mode 100644
index 4f24da330f..0000000000
--- a/src/python/grpcio/grpc/_cython/adapter_low.py
+++ /dev/null
@@ -1,102 +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.
-
-
-# Adapter from grpc._cython.types to the surface expected by
-# grpc._adapter._intermediary_low.
-#
-# TODO(atash): Once this is plugged into grpc._adapter._intermediary_low, remove
-# both grpc._adapter._intermediary_low and this file. The fore and rear links in
-# grpc._adapter should be able to use grpc._cython.types directly.
-
-from grpc._adapter import _types as type_interfaces
-from grpc._cython import cygrpc
-
-
-class ClientCredentials(object):
-  def __init__(self):
-    raise NotImplementedError()
-
-  @staticmethod
-  def google_default():
-    raise NotImplementedError()
-
-  @staticmethod
-  def ssl():
-    raise NotImplementedError()
-
-  @staticmethod
-  def composite():
-    raise NotImplementedError()
-
-  @staticmethod
-  def compute_engine():
-    raise NotImplementedError()
-
-  @staticmethod
-  def jwt():
-    raise NotImplementedError()
-
-  @staticmethod
-  def refresh_token():
-    raise NotImplementedError()
-
-  @staticmethod
-  def iam():
-    raise NotImplementedError()
-
-
-class ServerCredentials(object):
-  def __init__(self):
-    raise NotImplementedError()
-
-  @staticmethod
-  def ssl():
-    raise NotImplementedError()
-
-
-class CompletionQueue(type_interfaces.CompletionQueue):
-  def __init__(self):
-    raise NotImplementedError()
-
-
-class Call(type_interfaces.Call):
-  def __init__(self):
-    raise NotImplementedError()
-
-
-class Channel(type_interfaces.Channel):
-  def __init__(self):
-    raise NotImplementedError()
-
-
-class Server(type_interfaces.Server):
-  def __init__(self):
-    raise NotImplementedError()
-
diff --git a/src/python/grpcio/grpc/_cython/cygrpc.pyx b/src/python/grpcio/grpc/_cython/cygrpc.pyx
index b20dda8a95..16ec12dac0 100644
--- a/src/python/grpcio/grpc/_cython/cygrpc.pyx
+++ b/src/python/grpcio/grpc/_cython/cygrpc.pyx
@@ -44,6 +44,9 @@ from grpc._cython._cygrpc import completion_queue
 from grpc._cython._cygrpc import records
 from grpc._cython._cygrpc import server
 
+ConnectivityState = records.ConnectivityState
+ChannelArgKey = records.ChannelArgKey
+WriteFlag = records.WriteFlag
 StatusCode = records.StatusCode
 CallError = records.CallError
 CompletionType = records.CompletionType
@@ -73,6 +76,8 @@ Operations = records.Operations
 CallCredentials = credentials.CallCredentials
 ChannelCredentials = credentials.ChannelCredentials
 ServerCredentials = credentials.ServerCredentials
+CredentialsMetadataPlugin = credentials.CredentialsMetadataPlugin
+AuthMetadataContext = credentials.AuthMetadataContext
 
 channel_credentials_google_default = (
     credentials.channel_credentials_google_default)
@@ -88,6 +93,7 @@ call_credentials_jwt_access = (
 call_credentials_refresh_token = (
     credentials.call_credentials_google_refresh_token)
 call_credentials_google_iam = credentials.call_credentials_google_iam
+call_credentials_metadata_plugin = credentials.call_credentials_metadata_plugin
 server_credentials_ssl = credentials.server_credentials_ssl
 
 CompletionQueue = completion_queue.CompletionQueue
diff --git a/src/python/grpcio/grpc/_links/invocation.py b/src/python/grpcio/grpc/_links/invocation.py
index 67ef86a176..5ca0a0ee60 100644
--- a/src/python/grpcio/grpc/_links/invocation.py
+++ b/src/python/grpcio/grpc/_links/invocation.py
@@ -182,15 +182,15 @@ class _Kernel(object):
 
   def _on_finish_event(self, operation_id, event, rpc_state):
     _no_longer_due(_FINISH, rpc_state, operation_id, self._rpc_states)
-    if event.status.code is _intermediary_low.Code.OK:
+    if event.status.code == _intermediary_low.Code.OK:
       termination = links.Ticket.Termination.COMPLETION
-    elif event.status.code is _intermediary_low.Code.CANCELLED:
+    elif event.status.code == _intermediary_low.Code.CANCELLED:
       termination = links.Ticket.Termination.CANCELLATION
-    elif event.status.code is _intermediary_low.Code.DEADLINE_EXCEEDED:
+    elif event.status.code == _intermediary_low.Code.DEADLINE_EXCEEDED:
       termination = links.Ticket.Termination.EXPIRATION
-    elif event.status.code is _intermediary_low.Code.UNIMPLEMENTED:
+    elif event.status.code == _intermediary_low.Code.UNIMPLEMENTED:
       termination = links.Ticket.Termination.REMOTE_FAILURE
-    elif event.status.code is _intermediary_low.Code.UNKNOWN:
+    elif event.status.code == _intermediary_low.Code.UNKNOWN:
       termination = links.Ticket.Termination.LOCAL_FAILURE
     else:
       termination = links.Ticket.Termination.TRANSMISSION_FAILURE
@@ -262,7 +262,7 @@ class _Kernel(object):
         self._channel, self._completion_queue, '/%s/%s' % (group, method),
         self._host, time.time() + timeout)
     if options is not None and options.credentials is not None:
-      call.set_credentials(options.credentials._intermediary_low_credentials)
+      call.set_credentials(options.credentials._low_credentials)
     if transformed_initial_metadata is not None:
       for metadata_key, metadata_value in transformed_initial_metadata:
         call.add_metadata(metadata_key, metadata_value)
diff --git a/src/python/grpcio/grpc/_links/service.py b/src/python/grpcio/grpc/_links/service.py
index f56df84007..01edee6896 100644
--- a/src/python/grpcio/grpc/_links/service.py
+++ b/src/python/grpcio/grpc/_links/service.py
@@ -254,12 +254,12 @@ class _Kernel(object):
     rpc_state = self._rpc_states[call]
     _no_longer_due(_FINISH, rpc_state, call, self._rpc_states)
     code = event.status.code
-    if code is _intermediary_low.Code.OK:
+    if code == _intermediary_low.Code.OK:
       return
 
-    if code is _intermediary_low.Code.CANCELLED:
+    if code == _intermediary_low.Code.CANCELLED:
       termination = links.Ticket.Termination.CANCELLATION
-    elif code is _intermediary_low.Code.DEADLINE_EXCEEDED:
+    elif code == _intermediary_low.Code.DEADLINE_EXCEEDED:
       termination = links.Ticket.Termination.EXPIRATION
     else:
       termination = links.Ticket.Termination.TRANSMISSION_FAILURE
diff --git a/src/python/grpcio/grpc/beta/_server.py b/src/python/grpcio/grpc/beta/_server.py
index 4f454437c0..2b520cc7e5 100644
--- a/src/python/grpcio/grpc/beta/_server.py
+++ b/src/python/grpcio/grpc/beta/_server.py
@@ -170,7 +170,7 @@ class _Server(interfaces.Server):
     with self._lock:
       if self._end_link is None:
         return self._grpc_link.add_port(
-            address, server_credentials._intermediary_low_credentials)  # pylint: disable=protected-access
+            address, server_credentials._low_credentials)  # pylint: disable=protected-access
       else:
         raise ValueError('Can\'t add port to serving server!')
 
diff --git a/src/python/grpcio/grpc/beta/implementations.py b/src/python/grpcio/grpc/beta/implementations.py
index c9d64ad35a..a0ca330d2c 100644
--- a/src/python/grpcio/grpc/beta/implementations.py
+++ b/src/python/grpcio/grpc/beta/implementations.py
@@ -36,6 +36,7 @@ import threading  # pylint: disable=unused-import
 
 # cardinality and face are referenced from specification in this module.
 from grpc._adapter import _intermediary_low
+from grpc._adapter import _low
 from grpc._adapter import _types
 from grpc.beta import _connectivity_channel
 from grpc.beta import _server
@@ -48,7 +49,7 @@ _CHANNEL_SUBSCRIPTION_CALLBACK_ERROR_LOG_MESSAGE = (
     'Exception calling channel subscription callback!')
 
 
-class ClientCredentials(object):
+class ChannelCredentials(object):
   """A value encapsulating the data required to create a secure Channel.
 
   This class and its instances have no supported interface - it exists to define
@@ -56,13 +57,12 @@ class ClientCredentials(object):
   functions.
   """
 
-  def __init__(self, low_credentials, intermediary_low_credentials):
+  def __init__(self, low_credentials):
     self._low_credentials = low_credentials
-    self._intermediary_low_credentials = intermediary_low_credentials
 
 
-def ssl_client_credentials(root_certificates, private_key, certificate_chain):
-  """Creates a ClientCredentials for use with an SSL-enabled Channel.
+def ssl_channel_credentials(root_certificates, private_key, certificate_chain):
+  """Creates a ChannelCredentials for use with an SSL-enabled Channel.
 
   Args:
     root_certificates: The PEM-encoded root certificates or None to ask for
@@ -73,12 +73,73 @@ def ssl_client_credentials(root_certificates, private_key, certificate_chain):
       certificate chain should be used.
 
   Returns:
-    A ClientCredentials for use with an SSL-enabled Channel.
+    A ChannelCredentials for use with an SSL-enabled Channel.
   """
-  intermediary_low_credentials = _intermediary_low.ClientCredentials(
-      root_certificates, private_key, certificate_chain)
-  return ClientCredentials(
-      intermediary_low_credentials._internal, intermediary_low_credentials)  # pylint: disable=protected-access
+  return ChannelCredentials(_low.channel_credentials_ssl(
+      root_certificates, private_key, certificate_chain))
+
+
+class CallCredentials(object):
+  """A value encapsulating data asserting an identity over an *established*
+  channel. May be composed with ChannelCredentials to always assert identity for
+  every call over that channel.
+
+  This class and its instances have no supported interface - it exists to define
+  the type of its instances and its instances exist to be passed to other
+  functions.
+  """
+
+  def __init__(self, low_credentials):
+    self._low_credentials = low_credentials
+
+
+def metadata_call_credentials(metadata_plugin, name=None):
+  """Construct CallCredentials from an interfaces.GRPCAuthMetadataPlugin.
+
+  Args:
+    metadata_plugin: An interfaces.GRPCAuthMetadataPlugin to use in constructing
+      the CallCredentials object.
+
+  Returns:
+    A CallCredentials object for use in a GRPCCallOptions object.
+  """
+  if name is None:
+    name = metadata_plugin.__name__
+  return CallCredentials(
+      _low.call_credentials_metadata_plugin(metadata_plugin, name))
+
+def composite_call_credentials(call_credentials, additional_call_credentials):
+  """Compose two CallCredentials to make a new one.
+
+  Args:
+    call_credentials: A CallCredentials object.
+    additional_call_credentials: Another CallCredentials object to compose on
+      top of call_credentials.
+
+  Returns:
+    A CallCredentials object for use in a GRPCCallOptions object.
+  """
+  return CallCredentials(
+      _low.call_credentials_composite(
+          call_credentials._low_credentials,
+          additional_call_credentials._low_credentials))
+
+def composite_channel_credentials(channel_credentials,
+                                 additional_call_credentials):
+  """Compose ChannelCredentials on top of client credentials to make a new one.
+
+  Args:
+    channel_credentials: A ChannelCredentials object.
+    additional_call_credentials: A CallCredentials object to compose on
+      top of channel_credentials.
+
+  Returns:
+    A ChannelCredentials object for use in a GRPCCallOptions object.
+  """
+  return ChannelCredentials(
+      _low.channel_credentials_composite(
+          channel_credentials._low_credentials,
+          additional_call_credentials._low_credentials))
 
 
 class Channel(object):
@@ -135,19 +196,19 @@ def insecure_channel(host, port):
   return Channel(intermediary_low_channel._internal, intermediary_low_channel)  # pylint: disable=protected-access
 
 
-def secure_channel(host, port, client_credentials):
+def secure_channel(host, port, channel_credentials):
   """Creates a secure Channel to a remote host.
 
   Args:
     host: The name of the remote host to which to connect.
     port: The port of the remote host to which to connect.
-    client_credentials: A ClientCredentials.
+    channel_credentials: A ChannelCredentials.
 
   Returns:
     A secure Channel to the remote host through which RPCs may be conducted.
   """
   intermediary_low_channel = _intermediary_low.Channel(
-      '%s:%d' % (host, port), client_credentials._intermediary_low_credentials)
+      '%s:%d' % (host, port), channel_credentials._low_credentials)
   return Channel(intermediary_low_channel._internal, intermediary_low_channel)  # pylint: disable=protected-access
 
 
@@ -251,9 +312,8 @@ class ServerCredentials(object):
   functions.
   """
 
-  def __init__(self, low_credentials, intermediary_low_credentials):
+  def __init__(self, low_credentials):
     self._low_credentials = low_credentials
-    self._intermediary_low_credentials = intermediary_low_credentials
 
 
 def ssl_server_credentials(
@@ -282,11 +342,9 @@ def ssl_server_credentials(
     raise ValueError(
         'Illegal to require client auth without providing root certificates!')
   else:
-    intermediary_low_credentials = _intermediary_low.ServerCredentials(
+    return ServerCredentials(_low.server_credentials_ssl(
         root_certificates, private_key_certificate_chain_pairs,
-        require_client_auth)
-    return ServerCredentials(
-        intermediary_low_credentials._internal, intermediary_low_credentials)  # pylint: disable=protected-access
+        require_client_auth))
 
 
 class ServerOptions(object):
diff --git a/src/python/grpcio/grpc/beta/interfaces.py b/src/python/grpcio/grpc/beta/interfaces.py
index d4ca56500f..0663119163 100644
--- a/src/python/grpcio/grpc/beta/interfaces.py
+++ b/src/python/grpcio/grpc/beta/interfaces.py
@@ -100,14 +100,55 @@ def grpc_call_options(disable_compression=False, credentials=None):
     disable_compression: A boolean indicating whether or not compression should
       be disabled for the request object of the RPC. Only valid for
       request-unary RPCs.
-    credentials: Reserved for gRPC per-call credentials. The type for this does
-      not exist yet at the Python level.
+    credentials: A CallCredentials object to use for the invoked RPC.
   """
-  if credentials is not None:
-    raise ValueError('`credentials` is a reserved argument')
   return GRPCCallOptions(disable_compression, None, credentials)
 
 
+class GRPCAuthMetadataContext(object):
+  """Provides information to call credentials metadata plugins.
+
+  Attributes:
+    service_url: A string URL of the service being called into.
+    method_name: A string of the fully qualified method name being called.
+  """
+  __metaclass__ = abc.ABCMeta
+
+
+class GRPCAuthMetadataPluginCallback(object):
+  """Callback object received by a metadata plugin."""
+  __metaclass__ = abc.ABCMeta
+
+  def __call__(self, metadata, error):
+    """Inform the gRPC runtime of the metadata to construct a CallCredentials.
+
+    Args:
+      metadata: An iterable of 2-sequences (e.g. tuples) of metadata key/value
+        pairs.
+      error: An Exception to indicate error or None to indicate success.
+    """
+    raise NotImplementedError()
+
+
+class GRPCAuthMetadataPlugin(object):
+  """
+  """
+  __metaclass__ = abc.ABCMeta
+
+  def __call__(self, context, callback):
+    """Invoke the plugin.
+
+    Must not block. Need only be called by the gRPC runtime.
+
+    Args:
+      context: A GRPCAuthMetadataContext providing information on what the
+        plugin is being used for.
+      callback: A GRPCAuthMetadataPluginCallback to be invoked either
+        synchronously or asynchronously.
+    """
+    raise NotImplementedError()
+
+
 class GRPCServicerContext(object):
   """Exposes gRPC-specific options and behaviors to code servicing RPCs."""
   __metaclass__ = abc.ABCMeta
diff --git a/src/python/grpcio/setup.py b/src/python/grpcio/setup.py
index 8ac185bd6b..a948ca1fac 100644
--- a/src/python/grpcio/setup.py
+++ b/src/python/grpcio/setup.py
@@ -57,19 +57,6 @@ ENABLE_CYTHON_TRACING = os.environ.get(
 # the installation.
 INSTALL_TESTS = os.environ.get('GRPC_PYTHON_INSTALL_TESTS', False)
 
-C_EXTENSION_SOURCES = (
-    'grpc/_adapter/_c/module.c',
-    'grpc/_adapter/_c/types.c',
-    'grpc/_adapter/_c/utility.c',
-    'grpc/_adapter/_c/types/call_credentials.c',
-    'grpc/_adapter/_c/types/channel_credentials.c',
-    'grpc/_adapter/_c/types/server_credentials.c',
-    'grpc/_adapter/_c/types/completion_queue.c',
-    'grpc/_adapter/_c/types/call.c',
-    'grpc/_adapter/_c/types/channel.c',
-    'grpc/_adapter/_c/types/server.c',
-)
-
 CYTHON_EXTENSION_PACKAGE_NAMES = ()
 
 CYTHON_EXTENSION_MODULE_NAMES = (
@@ -94,14 +81,6 @@ if not "darwin" in sys.platform:
     EXTENSION_LIBRARIES += ('rt',)
 
 
-C_EXTENSION_MODULE = _core.Extension(
-    'grpc._adapter._c', sources=list(C_EXTENSION_SOURCES),
-    include_dirs=list(EXTENSION_INCLUDE_DIRECTORIES),
-    libraries=list(EXTENSION_LIBRARIES)
-)
-EXTENSION_MODULES = [C_EXTENSION_MODULE]
-
-
 def cython_extensions(package_names, module_names, include_dirs, libraries,
                       build_with_cython=False):
   file_extension = 'pyx' if build_with_cython else 'c'
@@ -185,7 +164,7 @@ else:
 setuptools.setup(
     name='grpcio',
     version='0.11.0b2',
-    ext_modules=EXTENSION_MODULES + CYTHON_EXTENSION_MODULES,
+    ext_modules=CYTHON_EXTENSION_MODULES,
     packages=list(PACKAGES),
     package_dir=PACKAGE_DIRECTORIES,
     install_requires=INSTALL_REQUIRES,
diff --git a/src/python/grpcio/tests/interop/_secure_interop_test.py b/src/python/grpcio/tests/interop/_secure_interop_test.py
index a0fef1fc20..7e3061133f 100644
--- a/src/python/grpcio/tests/interop/_secure_interop_test.py
+++ b/src/python/grpcio/tests/interop/_secure_interop_test.py
@@ -55,7 +55,7 @@ class SecureInteropTest(
     self.server.start()
     self.stub = test_pb2.beta_create_TestService_stub(
         test_utilities.not_really_secure_channel(
-            '[::]', port, implementations.ssl_client_credentials(
+            '[::]', port, implementations.ssl_channel_credentials(
                 resources.test_root_certificates(), None, None),
                 _SERVER_HOST_OVERRIDE))
 
diff --git a/src/python/grpcio/tests/interop/client.py b/src/python/grpcio/tests/interop/client.py
index 9449ff5429..5c00bce014 100644
--- a/src/python/grpcio/tests/interop/client.py
+++ b/src/python/grpcio/tests/interop/client.py
@@ -94,7 +94,7 @@ def _stub(args):
 
     channel = test_utilities.not_really_secure_channel(
         args.server_host, args.server_port,
-        implementations.ssl_client_credentials(root_certificates, None, None),
+        implementations.ssl_channel_credentials(root_certificates, None, None),
         args.server_host_override)
     stub = test_pb2.beta_create_TestService_stub(
         channel, metadata_transformer=metadata_transformer)
diff --git a/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py b/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py
index 90ad0b9bcb..a6fd82388c 100644
--- a/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py
+++ b/src/python/grpcio/tests/unit/_adapter/_intermediary_low_test.py
@@ -115,6 +115,7 @@ class EchoTest(unittest.TestCase):
 
   def tearDown(self):
     self.server.stop()
+    self.server.cancel_all_calls()
     self.server_completion_queue.stop()
     self.client_completion_queue.stop()
     self.server_completion_queue_thread.join()
@@ -286,11 +287,6 @@ class EchoTest(unittest.TestCase):
                         set((server_trailing_metadata_key,
                              server_trailing_binary_metadata_key,)))
 
-    server_timeout_none_event = self.server_completion_queue.get(0)
-    self.assertIsNone(server_timeout_none_event)
-    client_timeout_none_event = self.client_completion_queue.get(0)
-    self.assertIsNone(client_timeout_none_event)
-
     self.assertSequenceEqual(test_data, server_data)
     self.assertSequenceEqual(test_data, client_data)
 
@@ -335,6 +331,7 @@ class CancellationTest(unittest.TestCase):
 
   def tearDown(self):
     self.server.stop()
+    self.server.cancel_all_calls()
     self.server_completion_queue.stop()
     self.client_completion_queue.stop()
     self.server_completion_queue_thread.join()
@@ -410,14 +407,9 @@ class CancellationTest(unittest.TestCase):
 
     finish_event = self.client_events.get()
     self.assertEqual(_low.Event.Kind.FINISH, finish_event.kind)
-    self.assertEqual(_low.Status(_low.Code.CANCELLED, 'Cancelled'), 
+    self.assertEqual(_low.Status(_low.Code.CANCELLED, 'Cancelled'),
                                  finish_event.status)
 
-    server_timeout_none_event = self.server_completion_queue.get(0)
-    self.assertIsNone(server_timeout_none_event)
-    client_timeout_none_event = self.client_completion_queue.get(0)
-    self.assertIsNone(client_timeout_none_event)
-
     self.assertSequenceEqual(test_data, server_data)
     self.assertSequenceEqual(test_data, client_data)
 
diff --git a/src/python/grpcio/tests/unit/_adapter/_low_test.py b/src/python/grpcio/tests/unit/_adapter/_low_test.py
index 39b6f247b4..ec46617996 100644
--- a/src/python/grpcio/tests/unit/_adapter/_low_test.py
+++ b/src/python/grpcio/tests/unit/_adapter/_low_test.py
@@ -80,11 +80,11 @@ class InsecureServerInsecureClient(unittest.TestCase):
     del self.client_channel
 
     self.client_completion_queue.shutdown()
-    while (self.client_completion_queue.next().type !=
+    while (self.client_completion_queue.next(float('+inf')).type !=
            _types.EventType.QUEUE_SHUTDOWN):
       pass
     self.server_completion_queue.shutdown()
-    while (self.server_completion_queue.next().type !=
+    while (self.server_completion_queue.next(float('+inf')).type !=
            _types.EventType.QUEUE_SHUTDOWN):
       pass
 
@@ -294,8 +294,12 @@ class HangingServerShutdown(unittest.TestCase):
 
     # Now try to shutdown the server and expect that we see server shutdown
     # almost immediately after calling cancel_all_calls.
+
+    # First attempt to cancel all calls before shutting down, and expect
+    # our state machine to catch the erroneous API use.
     with self.assertRaises(RuntimeError):
       self.server.cancel_all_calls()
+
     shutdown_tag = object()
     self.server.shutdown(shutdown_tag)
     pre_cancel_timestamp = time.time()
diff --git a/src/python/grpcio/tests/unit/_cython/adapter_low_test.py b/src/python/grpcio/tests/unit/_cython/adapter_low_test.py
deleted file mode 100644
index f1bec238cf..0000000000
--- a/src/python/grpcio/tests/unit/_cython/adapter_low_test.py
+++ /dev/null
@@ -1,187 +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.
-
-# Fork of grpc._adapter._low_test; the grpc._cython.types adapter in
-# grpc._cython.low should transparently support the semantics expected of
-# grpc._adapter._low.
-
-import time
-import unittest
-
-from grpc._adapter import _types
-from grpc._cython import adapter_low as _low
-
-
-class InsecureServerInsecureClient(unittest.TestCase):
-
-  def setUp(self):
-    self.server_completion_queue = _low.CompletionQueue()
-    self.server = _low.Server(self.server_completion_queue, [])
-    self.port = self.server.add_http2_port('[::]:0')
-    self.client_completion_queue = _low.CompletionQueue()
-    self.client_channel = _low.Channel('localhost:%d'%self.port, [])
-
-    self.server.start()
-
-  def tearDown(self):
-    self.server.shutdown()
-    del self.client_channel
-
-    self.client_completion_queue.shutdown()
-    while (self.client_completion_queue.next().type !=
-               _types.EventType.QUEUE_SHUTDOWN):
-      pass
-    self.server_completion_queue.shutdown()
-    while (self.server_completion_queue.next().type !=
-               _types.EventType.QUEUE_SHUTDOWN):
-      pass
-
-    del self.client_completion_queue
-    del self.server_completion_queue
-    del self.server
-
-  @unittest.skip('TODO(atash): implement grpc._cython.adapter_low')
-  def testEcho(self):
-    DEADLINE = time.time()+5
-    DEADLINE_TOLERANCE = 0.25
-    CLIENT_METADATA_ASCII_KEY = 'key'
-    CLIENT_METADATA_ASCII_VALUE = 'val'
-    CLIENT_METADATA_BIN_KEY = 'key-bin'
-    CLIENT_METADATA_BIN_VALUE = b'\0'*1000
-    SERVER_INITIAL_METADATA_KEY = 'init_me_me_me'
-    SERVER_INITIAL_METADATA_VALUE = 'whodawha?'
-    SERVER_TRAILING_METADATA_KEY = 'california_is_in_a_drought'
-    SERVER_TRAILING_METADATA_VALUE = 'zomg it is'
-    SERVER_STATUS_CODE = _types.StatusCode.OK
-    SERVER_STATUS_DETAILS = 'our work is never over'
-    REQUEST = 'in death a member of project mayhem has a name'
-    RESPONSE = 'his name is robert paulson'
-    METHOD = 'twinkies'
-    HOST = 'hostess'
-    server_request_tag = object()
-    request_call_result = self.server.request_call(self.server_completion_queue,
-                                                   server_request_tag)
-
-    self.assertEqual(_types.CallError.OK, request_call_result)
-
-    client_call_tag = object()
-    client_call = self.client_channel.create_call(self.client_completion_queue,
-                                                  METHOD, HOST, DEADLINE)
-    client_initial_metadata = [
-        (CLIENT_METADATA_ASCII_KEY, CLIENT_METADATA_ASCII_VALUE),
-        (CLIENT_METADATA_BIN_KEY, CLIENT_METADATA_BIN_VALUE)]
-    client_start_batch_result = client_call.start_batch([
-        _types.OpArgs.send_initial_metadata(client_initial_metadata),
-        _types.OpArgs.send_message(REQUEST),
-        _types.OpArgs.send_close_from_client(),
-        _types.OpArgs.recv_initial_metadata(),
-        _types.OpArgs.recv_message(),
-        _types.OpArgs.recv_status_on_client()
-    ], client_call_tag)
-    self.assertEqual(_types.CallError.OK, client_start_batch_result)
-
-    request_event = self.server_completion_queue.next(DEADLINE)
-    self.assertEqual(_types.EventType.OP_COMPLETE, request_event.type)
-    self.assertIsInstance(request_event.call, _low.Call)
-    self.assertIs(server_request_tag, request_event.tag)
-    self.assertEqual(1, len(request_event.results))
-    self.assertEqual(dict(client_initial_metadata),
-                      dict(request_event.results[0].initial_metadata))
-    self.assertEqual(METHOD, request_event.call_details.method)
-    self.assertEqual(HOST, request_event.call_details.host)
-    self.assertLess(abs(DEADLINE - request_event.call_details.deadline),
-                    DEADLINE_TOLERANCE)
-
-    server_call_tag = object()
-    server_call = request_event.call
-    server_initial_metadata = [
-        (SERVER_INITIAL_METADATA_KEY, SERVER_INITIAL_METADATA_VALUE)]
-    server_trailing_metadata = [
-        (SERVER_TRAILING_METADATA_KEY, SERVER_TRAILING_METADATA_VALUE)]
-    server_start_batch_result = server_call.start_batch([
-        _types.OpArgs.send_initial_metadata(server_initial_metadata),
-        _types.OpArgs.recv_message(),
-        _types.OpArgs.send_message(RESPONSE),
-        _types.OpArgs.recv_close_on_server(),
-        _types.OpArgs.send_status_from_server(
-            server_trailing_metadata, SERVER_STATUS_CODE, SERVER_STATUS_DETAILS)
-    ], server_call_tag)
-    self.assertEqual(_types.CallError.OK, server_start_batch_result)
-
-    client_event = self.client_completion_queue.next(DEADLINE)
-    server_event = self.server_completion_queue.next(DEADLINE)
-
-    self.assertEqual(6, len(client_event.results))
-    found_client_op_types = set()
-    for client_result in client_event.results:
-      # we expect each op type to be unique
-      self.assertNotIn(client_result.type, found_client_op_types)
-      found_client_op_types.add(client_result.type)
-      if client_result.type == _types.OpType.RECV_INITIAL_METADATA:
-        self.assertEqual(dict(server_initial_metadata),
-                          dict(client_result.initial_metadata))
-      elif client_result.type == _types.OpType.RECV_MESSAGE:
-        self.assertEqual(RESPONSE, client_result.message)
-      elif client_result.type == _types.OpType.RECV_STATUS_ON_CLIENT:
-        self.assertEqual(dict(server_trailing_metadata),
-                          dict(client_result.trailing_metadata))
-        self.assertEqual(SERVER_STATUS_DETAILS, client_result.status.details)
-        self.assertEqual(SERVER_STATUS_CODE, client_result.status.code)
-    self.assertEqual(set([
-          _types.OpType.SEND_INITIAL_METADATA,
-          _types.OpType.SEND_MESSAGE,
-          _types.OpType.SEND_CLOSE_FROM_CLIENT,
-          _types.OpType.RECV_INITIAL_METADATA,
-          _types.OpType.RECV_MESSAGE,
-          _types.OpType.RECV_STATUS_ON_CLIENT
-      ]), found_client_op_types)
-
-    self.assertEqual(5, len(server_event.results))
-    found_server_op_types = set()
-    for server_result in server_event.results:
-      self.assertNotIn(client_result.type, found_server_op_types)
-      found_server_op_types.add(server_result.type)
-      if server_result.type == _types.OpType.RECV_MESSAGE:
-        self.assertEqual(REQUEST, server_result.message)
-      elif server_result.type == _types.OpType.RECV_CLOSE_ON_SERVER:
-        self.assertFalse(server_result.cancelled)
-    self.assertEqual(set([
-          _types.OpType.SEND_INITIAL_METADATA,
-          _types.OpType.RECV_MESSAGE,
-          _types.OpType.SEND_MESSAGE,
-          _types.OpType.RECV_CLOSE_ON_SERVER,
-          _types.OpType.SEND_STATUS_FROM_SERVER
-      ]), found_server_op_types)
-
-    del client_call
-    del server_call
-
-
-if __name__ == '__main__':
-  unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/_cython/cygrpc_test.py b/src/python/grpcio/tests/unit/_cython/cygrpc_test.py
index 84ee5c9eb5..876da88de9 100644
--- a/src/python/grpcio/tests/unit/_cython/cygrpc_test.py
+++ b/src/python/grpcio/tests/unit/_cython/cygrpc_test.py
@@ -28,11 +28,24 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import time
+import threading
 import unittest
 
 from grpc._cython import cygrpc
 from tests.unit._cython import test_utilities
 from tests.unit import test_common
+from tests.unit import resources
+
+
+_SSL_HOST_OVERRIDE = 'foo.test.google.fr'
+_CALL_CREDENTIALS_METADATA_KEY = 'call-creds-key'
+_CALL_CREDENTIALS_METADATA_VALUE = 'call-creds-value'
+
+def _metadata_plugin_callback(context, callback):
+  callback(cygrpc.Metadata(
+      [cygrpc.Metadatum(_CALL_CREDENTIALS_METADATA_KEY,
+                        _CALL_CREDENTIALS_METADATA_VALUE)]),
+      cygrpc.StatusCode.ok, '')
 
 
 class TypeSmokeTest(unittest.TestCase):
@@ -89,7 +102,17 @@ class TypeSmokeTest(unittest.TestCase):
     channel = cygrpc.Channel('[::]:0', cygrpc.ChannelArgs([]))
     del channel
 
-  @unittest.skip('TODO(atash): undo skip after #2229 is merged')
+  def testCredentialsMetadataPluginUpDown(self):
+    plugin = cygrpc.CredentialsMetadataPlugin(
+        lambda ignored_a, ignored_b: None, '')
+    del plugin
+
+  def testCallCredentialsFromPluginUpDown(self):
+    plugin = cygrpc.CredentialsMetadataPlugin(_metadata_plugin_callback, '')
+    call_credentials = cygrpc.call_credentials_metadata_plugin(plugin)
+    del plugin
+    del call_credentials
+
   def testServerStartNoExplicitShutdown(self):
     server = cygrpc.Server()
     completion_queue = cygrpc.CompletionQueue()
@@ -99,7 +122,6 @@ class TypeSmokeTest(unittest.TestCase):
     server.start()
     del server
 
-  @unittest.skip('TODO(atash): undo skip after #2229 is merged')
   def testServerStartShutdown(self):
     completion_queue = cygrpc.CompletionQueue()
     server = cygrpc.Server()
@@ -262,5 +284,169 @@ class InsecureServerInsecureClient(unittest.TestCase):
     del server_call
 
 
+class SecureServerSecureClient(unittest.TestCase):
+
+  def setUp(self):
+    server_credentials = cygrpc.server_credentials_ssl(
+        None, [cygrpc.SslPemKeyCertPair(resources.private_key(),
+                                        resources.certificate_chain())], False)
+    channel_credentials = cygrpc.channel_credentials_ssl(
+        resources.test_root_certificates(), None)
+    self.server_completion_queue = cygrpc.CompletionQueue()
+    self.server = cygrpc.Server()
+    self.server.register_completion_queue(self.server_completion_queue)
+    self.port = self.server.add_http2_port('[::]:0', server_credentials)
+    self.server.start()
+    self.client_completion_queue = cygrpc.CompletionQueue()
+    client_channel_arguments = cygrpc.ChannelArgs([
+        cygrpc.ChannelArg(cygrpc.ChannelArgKey.ssl_target_name_override,
+                          _SSL_HOST_OVERRIDE)])
+    self.client_channel = cygrpc.Channel(
+        'localhost:{}'.format(self.port), client_channel_arguments,
+        channel_credentials)
+
+  def tearDown(self):
+    del self.server
+    del self.client_completion_queue
+    del self.server_completion_queue
+
+  def testEcho(self):
+    DEADLINE = time.time()+5
+    DEADLINE_TOLERANCE = 0.25
+    CLIENT_METADATA_ASCII_KEY = b'key'
+    CLIENT_METADATA_ASCII_VALUE = b'val'
+    CLIENT_METADATA_BIN_KEY = b'key-bin'
+    CLIENT_METADATA_BIN_VALUE = b'\0'*1000
+    SERVER_INITIAL_METADATA_KEY = b'init_me_me_me'
+    SERVER_INITIAL_METADATA_VALUE = b'whodawha?'
+    SERVER_TRAILING_METADATA_KEY = b'california_is_in_a_drought'
+    SERVER_TRAILING_METADATA_VALUE = b'zomg it is'
+    SERVER_STATUS_CODE = cygrpc.StatusCode.ok
+    SERVER_STATUS_DETAILS = b'our work is never over'
+    REQUEST = b'in death a member of project mayhem has a name'
+    RESPONSE = b'his name is robert paulson'
+    METHOD = b'/twinkies'
+    HOST = None  # Default host
+
+    cygrpc_deadline = cygrpc.Timespec(DEADLINE)
+
+    server_request_tag = object()
+    request_call_result = self.server.request_call(
+        self.server_completion_queue, self.server_completion_queue,
+        server_request_tag)
+
+    self.assertEqual(cygrpc.CallError.ok, request_call_result)
+
+    plugin = cygrpc.CredentialsMetadataPlugin(_metadata_plugin_callback, '')
+    call_credentials = cygrpc.call_credentials_metadata_plugin(plugin)
+
+    client_call_tag = object()
+    client_call = self.client_channel.create_call(
+        None, 0, self.client_completion_queue, METHOD, HOST, cygrpc_deadline)
+    client_call.set_credentials(call_credentials)
+    client_initial_metadata = cygrpc.Metadata([
+        cygrpc.Metadatum(CLIENT_METADATA_ASCII_KEY,
+                         CLIENT_METADATA_ASCII_VALUE),
+        cygrpc.Metadatum(CLIENT_METADATA_BIN_KEY, CLIENT_METADATA_BIN_VALUE)])
+    client_start_batch_result = client_call.start_batch(cygrpc.Operations([
+        cygrpc.operation_send_initial_metadata(client_initial_metadata),
+        cygrpc.operation_send_message(REQUEST),
+        cygrpc.operation_send_close_from_client(),
+        cygrpc.operation_receive_initial_metadata(),
+        cygrpc.operation_receive_message(),
+        cygrpc.operation_receive_status_on_client()
+    ]), client_call_tag)
+    self.assertEqual(cygrpc.CallError.ok, client_start_batch_result)
+    client_event_future = test_utilities.CompletionQueuePollFuture(
+        self.client_completion_queue, cygrpc_deadline)
+
+    request_event = self.server_completion_queue.poll(cygrpc_deadline)
+    self.assertEqual(cygrpc.CompletionType.operation_complete,
+                      request_event.type)
+    self.assertIsInstance(request_event.operation_call, cygrpc.Call)
+    self.assertIs(server_request_tag, request_event.tag)
+    self.assertEqual(0, len(request_event.batch_operations))
+    client_metadata_with_credentials = list(client_initial_metadata) + [
+        (_CALL_CREDENTIALS_METADATA_KEY, _CALL_CREDENTIALS_METADATA_VALUE)]
+    self.assertTrue(
+        test_common.metadata_transmitted(client_metadata_with_credentials,
+                                         request_event.request_metadata))
+    self.assertEqual(METHOD, request_event.request_call_details.method)
+    self.assertEqual(_SSL_HOST_OVERRIDE,
+                     request_event.request_call_details.host)
+    self.assertLess(
+        abs(DEADLINE - float(request_event.request_call_details.deadline)),
+        DEADLINE_TOLERANCE)
+
+    server_call_tag = object()
+    server_call = request_event.operation_call
+    server_initial_metadata = cygrpc.Metadata([
+        cygrpc.Metadatum(SERVER_INITIAL_METADATA_KEY,
+                         SERVER_INITIAL_METADATA_VALUE)])
+    server_trailing_metadata = cygrpc.Metadata([
+        cygrpc.Metadatum(SERVER_TRAILING_METADATA_KEY,
+                         SERVER_TRAILING_METADATA_VALUE)])
+    server_start_batch_result = server_call.start_batch([
+        cygrpc.operation_send_initial_metadata(server_initial_metadata),
+        cygrpc.operation_receive_message(),
+        cygrpc.operation_send_message(RESPONSE),
+        cygrpc.operation_receive_close_on_server(),
+        cygrpc.operation_send_status_from_server(
+            server_trailing_metadata, SERVER_STATUS_CODE, SERVER_STATUS_DETAILS)
+    ], server_call_tag)
+    self.assertEqual(cygrpc.CallError.ok, server_start_batch_result)
+
+    client_event = client_event_future.result()
+    server_event = self.server_completion_queue.poll(cygrpc_deadline)
+
+    self.assertEqual(6, len(client_event.batch_operations))
+    found_client_op_types = set()
+    for client_result in client_event.batch_operations:
+      # we expect each op type to be unique
+      self.assertNotIn(client_result.type, found_client_op_types)
+      found_client_op_types.add(client_result.type)
+      if client_result.type == cygrpc.OperationType.receive_initial_metadata:
+        self.assertTrue(
+            test_common.metadata_transmitted(server_initial_metadata,
+                                             client_result.received_metadata))
+      elif client_result.type == cygrpc.OperationType.receive_message:
+        self.assertEqual(RESPONSE, client_result.received_message.bytes())
+      elif client_result.type == cygrpc.OperationType.receive_status_on_client:
+        self.assertTrue(
+            test_common.metadata_transmitted(server_trailing_metadata,
+                                             client_result.received_metadata))
+        self.assertEqual(SERVER_STATUS_DETAILS,
+                         client_result.received_status_details)
+        self.assertEqual(SERVER_STATUS_CODE, client_result.received_status_code)
+    self.assertEqual(set([
+          cygrpc.OperationType.send_initial_metadata,
+          cygrpc.OperationType.send_message,
+          cygrpc.OperationType.send_close_from_client,
+          cygrpc.OperationType.receive_initial_metadata,
+          cygrpc.OperationType.receive_message,
+          cygrpc.OperationType.receive_status_on_client
+      ]), found_client_op_types)
+
+    self.assertEqual(5, len(server_event.batch_operations))
+    found_server_op_types = set()
+    for server_result in server_event.batch_operations:
+      self.assertNotIn(client_result.type, found_server_op_types)
+      found_server_op_types.add(server_result.type)
+      if server_result.type == cygrpc.OperationType.receive_message:
+        self.assertEqual(REQUEST, server_result.received_message.bytes())
+      elif server_result.type == cygrpc.OperationType.receive_close_on_server:
+        self.assertFalse(server_result.received_cancelled)
+    self.assertEqual(set([
+          cygrpc.OperationType.send_initial_metadata,
+          cygrpc.OperationType.receive_message,
+          cygrpc.OperationType.send_message,
+          cygrpc.OperationType.receive_close_on_server,
+          cygrpc.OperationType.send_status_from_server
+      ]), found_server_op_types)
+
+    del client_call
+    del server_call
+
+
 if __name__ == '__main__':
   unittest.main(verbosity=2)
diff --git a/src/python/grpcio/tests/unit/beta/_beta_features_test.py b/src/python/grpcio/tests/unit/beta/_beta_features_test.py
index 5a7492ee9e..ea44177b49 100644
--- a/src/python/grpcio/tests/unit/beta/_beta_features_test.py
+++ b/src/python/grpcio/tests/unit/beta/_beta_features_test.py
@@ -42,6 +42,9 @@ from tests.unit.framework.common import test_constants
 
 _SERVER_HOST_OVERRIDE = 'foo.test.google.fr'
 
+_PER_RPC_CREDENTIALS_METADATA_KEY = 'my-call-credentials-metadata-key'
+_PER_RPC_CREDENTIALS_METADATA_VALUE = 'my-call-credentials-metadata-value'
+
 _GROUP = 'group'
 _UNARY_UNARY = 'unary-unary'
 _UNARY_STREAM = 'unary-stream'
@@ -63,6 +66,7 @@ class _Servicer(object):
     with self._condition:
       self._request = request
       self._peer = context.protocol_context().peer()
+      self._invocation_metadata = context.invocation_metadata()
       context.protocol_context().disable_next_response_compression()
       self._serviced = True
       self._condition.notify_all()
@@ -72,6 +76,7 @@ class _Servicer(object):
     with self._condition:
       self._request = request
       self._peer = context.protocol_context().peer()
+      self._invocation_metadata = context.invocation_metadata()
       context.protocol_context().disable_next_response_compression()
       self._serviced = True
       self._condition.notify_all()
@@ -83,6 +88,7 @@ class _Servicer(object):
       self._request = request
     with self._condition:
       self._peer = context.protocol_context().peer()
+      self._invocation_metadata = context.invocation_metadata()
       context.protocol_context().disable_next_response_compression()
       self._serviced = True
       self._condition.notify_all()
@@ -95,6 +101,7 @@ class _Servicer(object):
         context.protocol_context().disable_next_response_compression()
         yield _RESPONSE
     with self._condition:
+      self._invocation_metadata = context.invocation_metadata()
       self._serviced = True
       self._condition.notify_all()
 
@@ -137,6 +144,11 @@ class _BlockingIterator(object):
       self._condition.notify_all()
 
 
+def _metadata_plugin(context, callback):
+  callback([(_PER_RPC_CREDENTIALS_METADATA_KEY,
+             _PER_RPC_CREDENTIALS_METADATA_VALUE)], None)
+
+
 class BetaFeaturesTest(unittest.TestCase):
 
   def setUp(self):
@@ -167,10 +179,12 @@ class BetaFeaturesTest(unittest.TestCase):
         [(resources.private_key(), resources.certificate_chain(),),])
     port = self._server.add_secure_port('[::]:0', server_credentials)
     self._server.start()
-    self._client_credentials = implementations.ssl_client_credentials(
+    self._channel_credentials = implementations.ssl_channel_credentials(
         resources.test_root_certificates(), None, None)
+    self._call_credentials = implementations.metadata_call_credentials(
+        _metadata_plugin)
     channel = test_utilities.not_really_secure_channel(
-        'localhost', port, self._client_credentials, _SERVER_HOST_OVERRIDE)
+        'localhost', port, self._channel_credentials, _SERVER_HOST_OVERRIDE)
     stub_options = implementations.stub_options(
         thread_pool_size=test_constants.POOL_SIZE)
     self._dynamic_stub = implementations.dynamic_stub(
@@ -181,21 +195,36 @@ class BetaFeaturesTest(unittest.TestCase):
     self._server.stop(test_constants.SHORT_TIMEOUT).wait()
 
   def test_unary_unary(self):
-    call_options = interfaces.grpc_call_options(disable_compression=True)
+    call_options = interfaces.grpc_call_options(
+        disable_compression=True, credentials=self._call_credentials)
     response = getattr(self._dynamic_stub, _UNARY_UNARY)(
         _REQUEST, test_constants.LONG_TIMEOUT, protocol_options=call_options)
     self.assertEqual(_RESPONSE, response)
     self.assertIsNotNone(self._servicer.peer())
+    invocation_metadata = [(metadatum.key, metadatum.value) for metadatum in
+                           self._servicer._invocation_metadata]
+    self.assertIn(
+        (_PER_RPC_CREDENTIALS_METADATA_KEY,
+         _PER_RPC_CREDENTIALS_METADATA_VALUE),
+        invocation_metadata)
 
   def test_unary_stream(self):
-    call_options = interfaces.grpc_call_options(disable_compression=True)
+    call_options = interfaces.grpc_call_options(
+        disable_compression=True, credentials=self._call_credentials)
     response_iterator = getattr(self._dynamic_stub, _UNARY_STREAM)(
         _REQUEST, test_constants.LONG_TIMEOUT, protocol_options=call_options)
     self._servicer.block_until_serviced()
     self.assertIsNotNone(self._servicer.peer())
+    invocation_metadata = [(metadatum.key, metadatum.value) for metadatum in
+                           self._servicer._invocation_metadata]
+    self.assertIn(
+        (_PER_RPC_CREDENTIALS_METADATA_KEY,
+         _PER_RPC_CREDENTIALS_METADATA_VALUE),
+        invocation_metadata)
 
   def test_stream_unary(self):
-    call_options = interfaces.grpc_call_options()
+    call_options = interfaces.grpc_call_options(
+        credentials=self._call_credentials)
     request_iterator = _BlockingIterator(iter((_REQUEST,)))
     response_future = getattr(self._dynamic_stub, _STREAM_UNARY).future(
         request_iterator, test_constants.LONG_TIMEOUT,
@@ -207,9 +236,16 @@ class BetaFeaturesTest(unittest.TestCase):
     self._servicer.block_until_serviced()
     self.assertIsNotNone(self._servicer.peer())
     self.assertEqual(_RESPONSE, response_future.result())
+    invocation_metadata = [(metadatum.key, metadatum.value) for metadatum in
+                           self._servicer._invocation_metadata]
+    self.assertIn(
+        (_PER_RPC_CREDENTIALS_METADATA_KEY,
+         _PER_RPC_CREDENTIALS_METADATA_VALUE),
+        invocation_metadata)
 
   def test_stream_stream(self):
-    call_options = interfaces.grpc_call_options()
+    call_options = interfaces.grpc_call_options(
+        credentials=self._call_credentials)
     request_iterator = _BlockingIterator(iter((_REQUEST,)))
     response_iterator = getattr(self._dynamic_stub, _STREAM_STREAM)(
         request_iterator, test_constants.SHORT_TIMEOUT,
@@ -222,6 +258,12 @@ class BetaFeaturesTest(unittest.TestCase):
     self._servicer.block_until_serviced()
     self.assertIsNotNone(self._servicer.peer())
     self.assertEqual(_RESPONSE, response)
+    invocation_metadata = [(metadatum.key, metadatum.value) for metadatum in
+                           self._servicer._invocation_metadata]
+    self.assertIn(
+        (_PER_RPC_CREDENTIALS_METADATA_KEY,
+         _PER_RPC_CREDENTIALS_METADATA_VALUE),
+        invocation_metadata)
 
 
 class ContextManagementAndLifecycleTest(unittest.TestCase):
@@ -250,7 +292,7 @@ class ContextManagementAndLifecycleTest(unittest.TestCase):
         thread_pool_size=test_constants.POOL_SIZE)
     self._server_credentials = implementations.ssl_server_credentials(
         [(resources.private_key(), resources.certificate_chain(),),])
-    self._client_credentials = implementations.ssl_client_credentials(
+    self._channel_credentials = implementations.ssl_channel_credentials(
         resources.test_root_certificates(), None, None)
     self._stub_options = implementations.stub_options(
         thread_pool_size=test_constants.POOL_SIZE)
@@ -262,7 +304,7 @@ class ContextManagementAndLifecycleTest(unittest.TestCase):
     server.start()
 
     channel = test_utilities.not_really_secure_channel(
-        'localhost', port, self._client_credentials, _SERVER_HOST_OVERRIDE)
+        'localhost', port, self._channel_credentials, _SERVER_HOST_OVERRIDE)
     dynamic_stub = implementations.dynamic_stub(
         channel, _GROUP, self._cardinalities, options=self._stub_options)
     for _ in range(100):
diff --git a/src/python/grpcio/tests/unit/beta/_face_interface_test.py b/src/python/grpcio/tests/unit/beta/_face_interface_test.py
index 55c0d20060..1c21dfd03d 100644
--- a/src/python/grpcio/tests/unit/beta/_face_interface_test.py
+++ b/src/python/grpcio/tests/unit/beta/_face_interface_test.py
@@ -91,10 +91,10 @@ class _Implementation(test_interfaces.Implementation):
         [(resources.private_key(), resources.certificate_chain(),),])
     port = server.add_secure_port('[::]:0', server_credentials)
     server.start()
-    client_credentials = implementations.ssl_client_credentials(
+    channel_credentials = implementations.ssl_channel_credentials(
         resources.test_root_certificates(), None, None)
     channel = test_utilities.not_really_secure_channel(
-        'localhost', port, client_credentials, _SERVER_HOST_OVERRIDE)
+        'localhost', port, channel_credentials, _SERVER_HOST_OVERRIDE)
     stub_options = implementations.stub_options(
         request_serializers=serialization_behaviors.request_serializers,
         response_deserializers=serialization_behaviors.response_deserializers,
diff --git a/src/python/grpcio/tests/unit/beta/test_utilities.py b/src/python/grpcio/tests/unit/beta/test_utilities.py
index 24a8600e12..0313e06a93 100644
--- a/src/python/grpcio/tests/unit/beta/test_utilities.py
+++ b/src/python/grpcio/tests/unit/beta/test_utilities.py
@@ -34,13 +34,13 @@ from grpc.beta import implementations
 
 
 def not_really_secure_channel(
-    host, port, client_credentials, server_host_override):
+    host, port, channel_credentials, server_host_override):
   """Creates an insecure Channel to a remote host.
 
   Args:
     host: The name of the remote host to which to connect.
     port: The port of the remote host to which to connect.
-    client_credentials: The implementations.ClientCredentials with which to
+    channel_credentials: The implementations.ChannelCredentials with which to
       connect.
     server_host_override: The target name used for SSL host name checking.
 
@@ -50,7 +50,7 @@ def not_really_secure_channel(
   """
   hostport = '%s:%d' % (host, port)
   intermediary_low_channel = _intermediary_low.Channel(
-      hostport, client_credentials._intermediary_low_credentials,
+      hostport, channel_credentials._low_credentials,
       server_host_override=server_host_override)
   return implementations.Channel(
       intermediary_low_channel._internal, intermediary_low_channel)