diff --git a/pkg/app/api/grpcapi/web_api.go b/pkg/app/api/grpcapi/web_api.go
index f0eb8e144b..80857efdeb 100644
--- a/pkg/app/api/grpcapi/web_api.go
+++ b/pkg/app/api/grpcapi/web_api.go
@@ -1309,3 +1309,8 @@ func (a *WebAPI) ListAPIKeys(ctx context.Context, req *webservice.ListAPIKeysReq
 		Keys: apiKeys,
 	}, nil
 }
+
+// GetInsightData returns the accumulated insight data.
+func (a *WebAPI) GetInsightData(_ context.Context, _ *webservice.GetInsightDataRequest) (*webservice.GetInsightDataResponse, error) {
+	return nil, status.Error(codes.Unimplemented, "")
+}
diff --git a/pkg/app/api/service/webservice/service.proto b/pkg/app/api/service/webservice/service.proto
index 18e560f296..ceb2b02395 100644
--- a/pkg/app/api/service/webservice/service.proto
+++ b/pkg/app/api/service/webservice/service.proto
@@ -19,6 +19,7 @@ option go_package = "github.com/pipe-cd/pipe/pkg/app/api/service/webservice";
 
 import "validate/validate.proto";
 import "pkg/model/common.proto";
+import "pkg/model/insight.proto";
 import "pkg/model/application.proto";
 import "pkg/model/application_live_state.proto";
 import "pkg/model/command.proto";
@@ -85,6 +86,9 @@ service WebService {
     rpc GenerateAPIKey(GenerateAPIKeyRequest) returns (GenerateAPIKeyResponse) {}
     rpc DisableAPIKey(DisableAPIKeyRequest) returns (DisableAPIKeyResponse) {}
     rpc ListAPIKeys(ListAPIKeysRequest) returns (ListAPIKeysResponse) {}
+
+    // Insights
+    rpc GetInsightData(GetInsightDataRequest) returns (GetInsightDataResponse) {}
 }
 
 message AddEnvironmentResponse {
@@ -401,3 +405,16 @@ message ListAPIKeysRequest {
 message ListAPIKeysResponse {
     repeated model.APIKey keys = 1;
 }
+
+message GetInsightDataRequest {
+    pipe.model.InsightMetricsKind metrics_kind = 1 [(validate.rules).enum.defined_only = true];
+    pipe.model.InsightStep step = 2 [(validate.rules).enum.defined_only = true];
+    int64 range_from = 3 [(validate.rules).int64.gt = 0];
+    int64 range_to = 4 [(validate.rules).int64.gt = 0];
+    string application_id = 5;
+}
+
+message GetInsightDataResponse {
+    int64 updated_at = 1;
+    repeated pipe.model.InsightDataPoint data_points = 2;
+}
diff --git a/pkg/model/BUILD.bazel b/pkg/model/BUILD.bazel
index 2f7dd0e90f..cc55ea480c 100644
--- a/pkg/model/BUILD.bazel
+++ b/pkg/model/BUILD.bazel
@@ -13,6 +13,7 @@ proto_library(
         "environment.proto",
         "event.proto",
         "logblock.proto",
+        "insight.proto",
         "piped.proto",
         "piped_stats.proto",
         "project.proto",
diff --git a/pkg/model/insight.proto b/pkg/model/insight.proto
new file mode 100644
index 0000000000..35a774b4ed
--- /dev/null
+++ b/pkg/model/insight.proto
@@ -0,0 +1,39 @@
+// Copyright 2020 The PipeCD 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 pipe.model;
+option go_package = "github.com/pipe-cd/pipe/pkg/model";
+
+import "validate/validate.proto";
+
+message InsightDataPoint {
+  int64 timestamp = 1 [(validate.rules).int64.gt = 0];
+  float value = 2 [(validate.rules).float.gt = 0];
+}
+
+enum InsightMetricsKind {
+  DEPLOYMENT_FREQUENCY = 0;
+  CHANGE_FAILURE_RATE = 1;
+  MTTR = 2;
+  LEAD_TIME = 3;
+}
+
+enum InsightStep {
+  DAILY = 0;
+  WEEKLY = 1;
+  MONTHLY = 2;
+  YEARLY = 3;
+}