diff --git a/src/opencensus/proto/agent/metrics/v1/BUILD.bazel b/src/opencensus/proto/agent/metrics/v1/BUILD.bazel
index 0f31dfe..054474c 100644
--- a/src/opencensus/proto/agent/metrics/v1/BUILD.bazel
+++ b/src/opencensus/proto/agent/metrics/v1/BUILD.bazel
@@ -23,6 +23,7 @@ proto_library(
     deps = [
         "//opencensus/proto/agent/common/v1:common_proto",
         "//opencensus/proto/metrics/v1:metrics_proto",
+        "//opencensus/proto/resource/v1:resource_proto",
     ],
 )
 
@@ -51,6 +52,7 @@ go_proto_library(
     proto_deps = [
         "//opencensus/proto/agent/common/v1:common_proto_go",
         "//opencensus/proto/metrics/v1:metrics_proto_go",
+        "//opencensus/proto/resource/v1:resource_proto_go",
     ],
     pb_options = [
        # omit the go_package declared in proto files to make bazel works as expect
diff --git a/src/opencensus/proto/agent/metrics/v1/metrics_service.proto b/src/opencensus/proto/agent/metrics/v1/metrics_service.proto
index a74c210..f2aac28 100644
--- a/src/opencensus/proto/agent/metrics/v1/metrics_service.proto
+++ b/src/opencensus/proto/agent/metrics/v1/metrics_service.proto
@@ -18,6 +18,7 @@ package opencensus.proto.agent.metrics.v1;
 
 import "opencensus/proto/agent/common/v1/common.proto";
 import "opencensus/proto/metrics/v1/metrics.proto";
+import "opencensus/proto/resource/v1/resource.proto";
 
 option java_multiple_files = true;
 option java_package = "io.opencensus.proto.agent.metrics.v1";
@@ -42,6 +43,13 @@ message ExportMetricsServiceRequest {
 
   // A list of metrics that belong to the last received Node.
   repeated opencensus.proto.metrics.v1.Metric metrics = 2;
+
+  // The resource for the metrics in this message that do not have an explicit
+  // resource set.
+  // If unset, the most recently set resource in the RPC stream applies. It is
+  // valid to never be set within a stream, e.g. when no resource info is known
+  // at all or when all sent metrics have an explicit resource set.
+  opencensus.proto.resource.v1.Resource resource = 3;
 }
 
 message ExportMetricsServiceResponse {
diff --git a/src/opencensus/proto/agent/trace/v1/BUILD.bazel b/src/opencensus/proto/agent/trace/v1/BUILD.bazel
index a17c8e1..c571d2b 100644
--- a/src/opencensus/proto/agent/trace/v1/BUILD.bazel
+++ b/src/opencensus/proto/agent/trace/v1/BUILD.bazel
@@ -22,6 +22,7 @@ proto_library(
     srcs = ["trace_service.proto"],
     deps = [
         "//opencensus/proto/agent/common/v1:common_proto",
+        "//opencensus/proto/resource/v1:resource_proto",
         "//opencensus/proto/trace/v1:trace_proto",
         "//opencensus/proto/trace/v1:trace_config_proto",
     ],
@@ -51,6 +52,7 @@ go_proto_library(
     ],
     proto_deps = [
         "//opencensus/proto/agent/common/v1:common_proto_go",
+        "//opencensus/proto/resource/v1:resource_proto_go",
         "//opencensus/proto/trace/v1:trace_proto_go",
         "//opencensus/proto/trace/v1:trace_config_proto_go",
     ],
diff --git a/src/opencensus/proto/agent/trace/v1/trace_service.proto b/src/opencensus/proto/agent/trace/v1/trace_service.proto
index a413ed2..ed564ac 100644
--- a/src/opencensus/proto/agent/trace/v1/trace_service.proto
+++ b/src/opencensus/proto/agent/trace/v1/trace_service.proto
@@ -20,6 +20,7 @@ syntax = "proto3";
 package opencensus.proto.agent.trace.v1;
 
 import "opencensus/proto/agent/common/v1/common.proto";
+import "opencensus/proto/resource/v1/resource.proto";
 import "opencensus/proto/trace/v1/trace.proto";
 import "opencensus/proto/trace/v1/trace_config.proto";
 
@@ -72,6 +73,12 @@ message ExportTraceServiceRequest {
 
   // A list of Spans that belong to the last received Node.
   repeated opencensus.proto.trace.v1.Span spans = 2;
+
+  // The resource for the spans in this message that do not have an explicit
+  // resource set.
+  // If unset, the most recently set resource in the RPC stream applies. It is
+  // valid to never be set within a stream, e.g. when no resource info is known.
+  opencensus.proto.resource.v1.Resource resource = 3;
 }
 
 message ExportTraceServiceResponse {
diff --git a/src/opencensus/proto/metrics/v1/BUILD.bazel b/src/opencensus/proto/metrics/v1/BUILD.bazel
index 9cbe63e..a46197d 100644
--- a/src/opencensus/proto/metrics/v1/BUILD.bazel
+++ b/src/opencensus/proto/metrics/v1/BUILD.bazel
@@ -22,6 +22,7 @@ proto_library(
     deps = [
         "@com_google_protobuf//:timestamp_proto",
         "@com_google_protobuf//:wrappers_proto",
+        "//opencensus/proto/resource/v1:resource_proto",
     ],
 )
 
@@ -48,6 +49,9 @@ go_proto_library(
        # omit the go_package declared in proto files to make bazel works as expect
        "paths=source_relative",
     ],
+    proto_deps = [
+        "//opencensus/proto/resource/v1:resource_proto_go",
+    ],
     deps = [
         "@com_github_golang_protobuf//ptypes/timestamp:go_default_library",
         "@com_github_golang_protobuf//ptypes/wrappers:go_default_library",
diff --git a/src/opencensus/proto/metrics/v1/metrics.proto b/src/opencensus/proto/metrics/v1/metrics.proto
index dee16eb..3f1ca42 100644
--- a/src/opencensus/proto/metrics/v1/metrics.proto
+++ b/src/opencensus/proto/metrics/v1/metrics.proto
@@ -23,6 +23,7 @@ package opencensus.proto.metrics.v1;
 
 import "google/protobuf/timestamp.proto";
 import "google/protobuf/wrappers.proto";
+import "opencensus/proto/resource/v1/resource.proto";
 
 option go_package = "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1";
 
@@ -48,6 +49,10 @@ message Metric {
   // One or more timeseries for a single metric, where each timeseries has
   // one or more points.
   repeated TimeSeries timeseries = 3;
+
+  // The resource for the metric. If unset, it may be set to a default value
+  // provided for a sequence of messages in an RPC stream.
+  opencensus.proto.resource.v1.Resource resource = 4;
 }
 
 // Defines a metric type and its schema.
diff --git a/src/opencensus/proto/resource/v1/BUILD.bazel b/src/opencensus/proto/resource/v1/BUILD.bazel
new file mode 100644
index 0000000..b5da614
--- /dev/null
+++ b/src/opencensus/proto/resource/v1/BUILD.bazel
@@ -0,0 +1,41 @@
+# Copyright 2018, OpenCensus Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//visibility:public"])
+
+load("@org_pubref_rules_protobuf//go:rules.bzl", "go_proto_library")
+
+proto_library(
+    name = "resource_proto",
+    srcs = ["resource.proto"],
+)
+
+cc_proto_library(
+    name = "resource_proto_cc",
+    deps = [":resource_proto"],
+)
+
+java_proto_library(
+    name = "resource_proto_java",
+    deps = [":resource_proto"],
+)
+
+go_proto_library(
+    name = "resource_proto_go",
+    protos = ["resource.proto"],
+    pb_options = [
+       # omit the go_package declared in proto files to make bazel works as expect
+       "paths=source_relative",
+    ],
+)
diff --git a/src/opencensus/proto/resource/v1/resource.proto b/src/opencensus/proto/resource/v1/resource.proto
new file mode 100644
index 0000000..61e5983
--- /dev/null
+++ b/src/opencensus/proto/resource/v1/resource.proto
@@ -0,0 +1,33 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package opencensus.proto.resource.v1;
+
+option go_package = "github.com/census-instrumentation/opencensus-proto/gen-go/resource/v1";
+
+option java_multiple_files = true;
+option java_package = "io.opencensus.proto.resource.v1";
+option java_outer_classname = "ResourceProto";
+
+// Resource information.
+message Resource {
+
+  // Type identifier for the resource.
+  string type = 1;
+
+  // Set of labels that describe the resource.
+  map<string,string> labels = 2;
+}