2 files changed, 14 insertions, 12 deletions
diff --git a/src/proto/census/trace_context.proto b/src/proto/census/trace_context.proto
index a5d5a9595d..fc0a54d2ce 100644
--- a/src/proto/census/trace_context.proto
+++ b/src/proto/census/trace_context.proto
@@ -31,18 +31,14 @@ syntax = "proto3";
 
 package google.trace;
 
-// A TraceId uniquely represents a single Trace. It is a 128-bit nonce.
-message TraceId {
-  fixed64 hi = 1;
-  fixed64 lo = 2;
-}
-
 // Tracing information that is propagated with RPC's.
 message TraceContext {
-  // Trace identifer. Must be present.
-  TraceId trace_id = 1;
-  // ID of parent (client) span. Must be present.
-  fixed64 span_id = 2;
-  // true if this trace is sampled.
-  bool is_sampled = 3;
+  // A TraceId uniquely represents a single Trace. It is a 128-bit nonce.
+  // The 128-bit ID is split into 2 64-bit chunks. (REQUIRED)
+  fixed64 trace_id_hi = 1;
+  fixed64 trace_id_lo = 2;
+  // ID of parent (client) span. (REQUIRED)
+  fixed64 span_id = 3;
+  // Span option flags. First bit is true if this trace is sampled. (OPTIONAL)
+  fixed32 span_options = 4;
 }
diff --git a/src/proto/grpc/testing/BUILD b/src/proto/grpc/testing/BUILD
index 283740839d..23a16a7cfc 100644
--- a/src/proto/grpc/testing/BUILD
+++ b/src/proto/grpc/testing/BUILD
@@ -42,11 +42,13 @@ grpc_proto_library(
     name = "control_proto",
     srcs = ["control.proto"],
     deps = ["payloads_proto", "stats_proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
     name = "echo_messages_proto",
     srcs = ["echo_messages.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
@@ -58,11 +60,13 @@ grpc_proto_library(
 grpc_proto_library(
     name = "empty_proto",
     srcs = ["empty.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
     name = "messages_proto",
     srcs = ["messages.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
@@ -73,6 +77,7 @@ grpc_proto_library(
 grpc_proto_library(
     name = "payloads_proto",
     srcs = ["payloads.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(
@@ -84,6 +89,7 @@ grpc_proto_library(
 grpc_proto_library(
     name = "stats_proto",
     srcs = ["stats.proto"],
+    has_services = False,
 )
 
 grpc_proto_library(