From a81fc6c2f5120bacb41ada83cace026e1e957ea4 Mon Sep 17 00:00:00 2001
From: Robert Voinescu <robertvoinescu@google.com>
Date: Mon, 31 Aug 2026 21:17:45 +0000
Subject: [PATCH 1/2] feat(BuiltInMetrics): Generate BuiltInMetrics project

---
 .github/renovate.json                         |  1 +
 Directory.Packages.props                      |  3 ++
 README.md                                     |  1 +
 .../.repo-metadata.json                       |  7 ++++
 ...oud.BuiltInMetrics.IntegrationTests.csproj | 25 ++++++++++++
 .../Google.Cloud.BuiltInMetrics.Tests.csproj  | 25 ++++++++++++
 .../Google.Cloud.BuiltInMetrics.sln           | 40 +++++++++++++++++++
 .../Google.Cloud.BuiltInMetrics.csproj        | 18 +++++++++
 generator-input/apis.json                     | 29 ++++++++++++++
 9 files changed, 149 insertions(+)
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/.repo-metadata.json
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/Google.Cloud.BuiltInMetrics.IntegrationTests.csproj
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/Google.Cloud.BuiltInMetrics.Tests.csproj
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.sln
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.csproj

diff --git a/.github/renovate.json b/.github/renovate.json
index 1081a0296fd2..d421a977f9a1 100644
--- a/.github/renovate.json
+++ b/.github/renovate.json
@@ -79,6 +79,7 @@
     "apis/Google.Cloud.BinaryAuthorization.V1/Google.Cloud.BinaryAuthorization.V1/**",
     "apis/Google.Cloud.BinaryAuthorization.V1Beta1/Google.Cloud.BinaryAuthorization.V1Beta1/**",
     "apis/Google.Cloud.CapacityPlanner.V1Beta/Google.Cloud.CapacityPlanner.V1Beta/**",
+    "apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/**",
     "apis/Google.Cloud.CertificateManager.V1/Google.Cloud.CertificateManager.V1/**",
     "apis/Google.Cloud.Ces.V1/Google.Cloud.Ces.V1/**",
     "apis/Google.Cloud.Ces.V1Beta/Google.Cloud.Ces.V1Beta/**",
diff --git a/Directory.Packages.props b/Directory.Packages.props
index 44bb8f6c09b8..9025054c10af 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -18,6 +18,7 @@
 
     <!-- Support libraries (rarely referenced directly) -->
     <PackageVersion Include="Google.Apis" Version="[1.73.0, 2.0.0)" />
+    <PackageVersion Include="Google.Apis.Auth" Version="[1.73.0, 2.0.0)" />
 
     <!--
       - The Google.Protobuf version should usually be the one that
@@ -69,5 +70,7 @@
     <PackageVersion Include="NLog" Version="5.5.1" />
     <PackageVersion Include="Grpc.AspNetCore" Version="2.83.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Server.Kestrel.Core" Version="2.3.12" />
+    <PackageVersion Include="OpenTelemetry" Version="1.17.0" />
+    <PackageVersion Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.17.0" />
   </ItemGroup>
 </Project>
diff --git a/README.md b/README.md
index 353c26e77b9e..6087922922fc 100644
--- a/README.md
+++ b/README.md
@@ -82,6 +82,7 @@ Each package name links to the documentation for that package.
 | [Google.Cloud.BinaryAuthorization.V1](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.BinaryAuthorization.V1/latest) | [![NuGet](https://img.shields.io/nuget/v/Google.Cloud.BinaryAuthorization.V1)](https://nuget.org/packages/Google.Cloud.BinaryAuthorization.V1) | [Binary Authorization (V1 API)](https://cloud.google.com/binary-authorization/docs/reference/rpc) |
 | [Google.Cloud.BinaryAuthorization.V1Beta1](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.BinaryAuthorization.V1Beta1/latest) | [![NuGet](https://img.shields.io/nuget/v/Google.Cloud.BinaryAuthorization.V1Beta1)](https://nuget.org/packages/Google.Cloud.BinaryAuthorization.V1Beta1) | [Binary Authorization (V1Beta1 API)](https://cloud.google.com/binary-authorization/docs/reference/rpc) |
 | [Google.Cloud.CapacityPlanner.V1Beta](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.CapacityPlanner.V1Beta/latest) | [![NuGet](https://img.shields.io/nuget/v/Google.Cloud.CapacityPlanner.V1Beta)](https://nuget.org/packages/Google.Cloud.CapacityPlanner.V1Beta) | [Capacity Planner](https://cloud.google.com/capacity-planner/docs) |
+| [Google.Cloud.BuiltInMetrics](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.BuiltInMetrics/latest) | [![NuGet](https://img.shields.io/nuget/v/Google.Cloud.BuiltInMetrics)](https://nuget.org/packages/Google.Cloud.BuiltInMetrics) | OpenTelemetry exporter and setup for Google Cloud client built-in metrics |
 | [Google.Cloud.CertificateManager.V1](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.CertificateManager.V1/latest) | [![NuGet](https://img.shields.io/nuget/v/Google.Cloud.CertificateManager.V1)](https://nuget.org/packages/Google.Cloud.CertificateManager.V1) | [Certificate Manager](https://cloud.google.com/certificate-manager/docs) |
 | [Google.Cloud.Ces.V1](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.Ces.V1/latest) | [![NuGet](https://img.shields.io/nuget/v/Google.Cloud.Ces.V1)](https://nuget.org/packages/Google.Cloud.Ces.V1) | [Gemini Enterprise for Customer Experience (V1 API)](https://docs.cloud.google.com/customer-engagement-ai/conversational-agents/ps) |
 | [Google.Cloud.Ces.V1Beta](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.Ces.V1Beta/latest) | [![NuGet](https://img.shields.io/nuget/v/Google.Cloud.Ces.V1Beta)](https://nuget.org/packages/Google.Cloud.Ces.V1Beta) | [Gemini Enterprise for Customer Experience (V1Beta API)](https://docs.cloud.google.com/customer-engagement-ai/conversational-agents/ps) |
diff --git a/apis/Google.Cloud.BuiltInMetrics/.repo-metadata.json b/apis/Google.Cloud.BuiltInMetrics/.repo-metadata.json
new file mode 100644
index 000000000000..c6b2b329d90d
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/.repo-metadata.json
@@ -0,0 +1,7 @@
+{
+  "distribution_name": "Google.Cloud.BuiltInMetrics",
+  "release_level": "preview",
+  "client_documentation": "https://cloud.google.com/dotnet/docs/reference/Google.Cloud.BuiltInMetrics/latest",
+  "library_type": "OTHER",
+  "language": "dotnet"
+}
\ No newline at end of file
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/Google.Cloud.BuiltInMetrics.IntegrationTests.csproj b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/Google.Cloud.BuiltInMetrics.IntegrationTests.csproj
new file mode 100644
index 000000000000..abea60b851cd
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/Google.Cloud.BuiltInMetrics.IntegrationTests.csproj
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>net8.0;net462</TargetFrameworks>
+    <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">net8.0</TargetFrameworks>
+    <IsPackable>false</IsPackable>
+    <NoWarn>$(NoWarn);1701;1702;1705;xUnit2004;xUnit2013</NoWarn>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Google.Api.Gax.Testing" />
+    <ProjectReference Include="..\Google.Cloud.BuiltInMetrics\Google.Cloud.BuiltInMetrics.csproj" />
+    <ProjectReference Include="..\..\..\tools\Google.Cloud.ClientTesting\Google.Cloud.ClientTesting.csproj" />
+    <PackageReference Include="Google.Cloud.Monitoring.V3" VersionOverride="[3.10.0, 4.0.0)" />
+    <ProjectReference Include="..\..\Google.Cloud.Spanner.Common.V1\Google.Cloud.Spanner.Common.V1\Google.Cloud.Spanner.Common.V1.csproj" />
+    <ProjectReference Include="..\..\Google.Cloud.Spanner.V1\Google.Cloud.Spanner.V1\Google.Cloud.Spanner.V1.csproj" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="NSubstitute" />
+    <PackageReference Include="System.Linq.AsyncEnumerable" />
+    <PackageReference Include="Xunit.SkippableFact" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio" />
+    <Service Include="{82a7f48d-3b50-4b1e-b82e-3ada8210c358}" />
+  </ItemGroup>
+  <Import Project="Google.Cloud.BuiltInMetrics.IntegrationTests.csproj.google" Condition="Exists('Google.Cloud.BuiltInMetrics.IntegrationTests.csproj.google')" />
+</Project>
\ No newline at end of file
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/Google.Cloud.BuiltInMetrics.Tests.csproj b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/Google.Cloud.BuiltInMetrics.Tests.csproj
new file mode 100644
index 000000000000..b130e9a49f8c
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/Google.Cloud.BuiltInMetrics.Tests.csproj
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFrameworks>net8.0;net462</TargetFrameworks>
+    <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">net8.0</TargetFrameworks>
+    <IsPackable>false</IsPackable>
+    <NoWarn>$(NoWarn);1701;1702;1705;xUnit2004;xUnit2013</NoWarn>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Google.Api.Gax.Testing" />
+    <ProjectReference Include="..\Google.Cloud.BuiltInMetrics\Google.Cloud.BuiltInMetrics.csproj" />
+    <ProjectReference Include="..\..\..\tools\Google.Cloud.ClientTesting\Google.Cloud.ClientTesting.csproj" />
+    <PackageReference Include="Google.Cloud.Monitoring.V3" VersionOverride="[3.10.0, 4.0.0)" />
+    <ProjectReference Include="..\..\Google.Cloud.Spanner.Common.V1\Google.Cloud.Spanner.Common.V1\Google.Cloud.Spanner.Common.V1.csproj" />
+    <ProjectReference Include="..\..\Google.Cloud.Spanner.V1\Google.Cloud.Spanner.V1\Google.Cloud.Spanner.V1.csproj" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="NSubstitute" />
+    <PackageReference Include="System.Linq.AsyncEnumerable" />
+    <PackageReference Include="Xunit.SkippableFact" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio" />
+    <Service Include="{82a7f48d-3b50-4b1e-b82e-3ada8210c358}" />
+  </ItemGroup>
+  <Import Project="Google.Cloud.BuiltInMetrics.Tests.csproj.google" Condition="Exists('Google.Cloud.BuiltInMetrics.Tests.csproj.google')" />
+</Project>
\ No newline at end of file
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.sln b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.sln
new file mode 100644
index 000000000000..cc70a1f0988c
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.sln
@@ -0,0 +1,40 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.2.32516.85
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Google.Cloud.BuiltInMetrics", "Google.Cloud.BuiltInMetrics\Google.Cloud.BuiltInMetrics.csproj", "{5B777731-1099-BABC-B0CD-B37656B5A0D4}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Google.Cloud.BuiltInMetrics.IntegrationTests", "Google.Cloud.BuiltInMetrics.IntegrationTests\Google.Cloud.BuiltInMetrics.IntegrationTests.csproj", "{57498B19-4CDE-6C71-8C23-C11A7E8EF8C4}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Google.Cloud.BuiltInMetrics.Tests", "Google.Cloud.BuiltInMetrics.Tests\Google.Cloud.BuiltInMetrics.Tests.csproj", "{B6701627-1EE4-E994-C32C-D7BF4C7A5AEA}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Google.Cloud.ClientTesting", "..\..\tools\Google.Cloud.ClientTesting\Google.Cloud.ClientTesting.csproj", "{29974B0C-A7B0-8CA8-AE32-99F622C89044}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{5B777731-1099-BABC-B0CD-B37656B5A0D4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5B777731-1099-BABC-B0CD-B37656B5A0D4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5B777731-1099-BABC-B0CD-B37656B5A0D4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5B777731-1099-BABC-B0CD-B37656B5A0D4}.Release|Any CPU.Build.0 = Release|Any CPU
+		{57498B19-4CDE-6C71-8C23-C11A7E8EF8C4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{57498B19-4CDE-6C71-8C23-C11A7E8EF8C4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{57498B19-4CDE-6C71-8C23-C11A7E8EF8C4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{57498B19-4CDE-6C71-8C23-C11A7E8EF8C4}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B6701627-1EE4-E994-C32C-D7BF4C7A5AEA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B6701627-1EE4-E994-C32C-D7BF4C7A5AEA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B6701627-1EE4-E994-C32C-D7BF4C7A5AEA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B6701627-1EE4-E994-C32C-D7BF4C7A5AEA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{29974B0C-A7B0-8CA8-AE32-99F622C89044}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{29974B0C-A7B0-8CA8-AE32-99F622C89044}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{29974B0C-A7B0-8CA8-AE32-99F622C89044}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{29974B0C-A7B0-8CA8-AE32-99F622C89044}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.csproj b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.csproj
new file mode 100644
index 000000000000..5d2302294749
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.csproj
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <Version>1.0.0-alpha01</Version>
+    <TargetFrameworks>netstandard2.0;net462</TargetFrameworks>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <Description>OpenTelemetry exporter and setup for Google Cloud client built-in metrics.</Description>
+    <PackageTags>OpenTelemetry;Metrics;Google;Cloud;Google;Cloud</PackageTags>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="ConfigureAwaitChecker.Analyzer" PrivateAssets="All" />
+    <PackageReference Include="Google.Api.Gax" />
+    <PackageReference Include="Google.Apis.Auth" />
+    <PackageReference Include="OpenTelemetry" />
+    <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" />
+  </ItemGroup>
+  <Import Project="Google.Cloud.BuiltInMetrics.csproj.google" Condition="Exists('Google.Cloud.BuiltInMetrics.csproj.google')" />
+</Project>
\ No newline at end of file
diff --git a/generator-input/apis.json b/generator-input/apis.json
index 6e1aedb946b0..cf72e52a0de9 100644
--- a/generator-input/apis.json
+++ b/generator-input/apis.json
@@ -1505,6 +1505,35 @@
       "transport": "grpc+rest",
       "restNumericEnums": true
     },
+    {
+      "id": "Google.Cloud.BuiltInMetrics",
+      "version": "1.0.0-alpha01",
+      "type": "other",
+      "targetFrameworks": "netstandard2.0;net462",
+      "description": "OpenTelemetry exporter and setup for Google Cloud client built-in metrics.",
+      "tags": [
+        "OpenTelemetry",
+        "Metrics",
+        "Google",
+        "Cloud"
+      ],
+      "dependencies": {
+        "Google.Api.Gax": "default",
+        "Google.Apis.Auth": "default",
+        "OpenTelemetry": "default",
+        "OpenTelemetry.Exporter.OpenTelemetryProtocol": "default"
+      },
+      "testDependencies": {
+        "Google.Api.Gax.Testing": "default",
+        "Google.Cloud.Monitoring.V3": "3.10.0",
+        "Google.Cloud.Spanner.Common.V1": "project",
+        "Google.Cloud.Spanner.V1": "project"
+      },
+      "projects": [
+        "IntegrationTests",
+        "Tests"
+      ]
+    },
     {
       "id": "Google.Cloud.CertificateManager.V1",
       "version": "2.9.0",

From 57e3e4afd1ed8c3d465c591e15ef1740ead883cd Mon Sep 17 00:00:00 2001
From: Robert Voinescu <robertvoinescu@google.com>
Date: Mon, 31 Aug 2026 21:19:21 +0000
Subject: [PATCH 2/2] feat(BuiltInMetrics): Add support for Spanner built in
 metrics

---
 .../SpannerBuiltInMetricsIntegrationTests.cs  | 158 ++++++++++++++++++
 .../SpannerMetricsConfigurationTests.cs       | 102 +++++++++++
 .../TestMetricExporter.cs                     |  49 ++++++
 .../AssemblyInfo.cs                           |  31 ++++
 .../BuiltInMetrics.cs                         | 156 +++++++++++++++++
 .../IServiceMetricsConfiguration.cs           |  29 ++++
 .../SpannerMetricsConfiguration.cs            |  96 +++++++++++
 7 files changed, 621 insertions(+)
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/SpannerBuiltInMetricsIntegrationTests.cs
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/SpannerMetricsConfigurationTests.cs
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/TestMetricExporter.cs
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/AssemblyInfo.cs
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/BuiltInMetrics.cs
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/IServiceMetricsConfiguration.cs
 create mode 100644 apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/SpannerMetricsConfiguration.cs

diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/SpannerBuiltInMetricsIntegrationTests.cs b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/SpannerBuiltInMetricsIntegrationTests.cs
new file mode 100644
index 000000000000..9c271333e1a0
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.IntegrationTests/SpannerBuiltInMetricsIntegrationTests.cs
@@ -0,0 +1,158 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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.
+
+using Google.Apis.Auth.OAuth2;
+using Google.Cloud.ClientTesting;
+using Google.Cloud.Monitoring.V3;
+using Google.Protobuf.WellKnownTypes;
+using Grpc.Core;
+using OpenTelemetry;
+using OpenTelemetry.Metrics;
+using OpenTelemetry.Resources;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.Metrics;
+using System.Linq;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Google.Cloud.BuiltInMetrics.IntegrationTests;
+
+public class SpannerBuiltInMetricsIntegrationTests
+{
+    private static readonly TimeSpan s_pollingTimeout = TimeSpan.FromMinutes(3);
+    private static readonly TimeSpan s_pollingInterval = TimeSpan.FromSeconds(10);
+
+    private static readonly string[] s_expectedMetrics =
+    [
+        "spanner.googleapis.com/client/operation_count",
+        "spanner.googleapis.com/client/operation_latencies",
+        "spanner.googleapis.com/client/attempt_count",
+        "spanner.googleapis.com/client/attempt_latencies",
+        "spanner.googleapis.com/client/gfe_latencies",
+        "spanner.googleapis.com/client/gfe_connectivity_error_count"
+    ];
+
+    [Fact]
+    public async Task BuiltInMetrics_ExportsAllSpannerTelemetryToMonitoring()
+    {
+        // Arrange the metrics to be emittted along with their labels
+        string projectId = TestEnvironment.GetTestProjectId();
+        var credential = await GoogleCredential.GetApplicationDefaultAsync();
+        string testClientName = $"spanner.net.test.{Guid.NewGuid().ToString().Substring(0, 5)}";
+        string testUid = Guid.NewGuid().ToString();
+
+        using var meterProvider = Sdk.CreateMeterProviderBuilder()
+            .SetResourceBuilder(ResourceBuilder.CreateDefault()
+                .AddService("spanner-built-in-metrics-integration-test", "test")
+                .AddAttributes(
+                [
+                    new KeyValuePair<string, object>("gcp.resource_type", "spanner_instance_client"),
+                    new KeyValuePair<string, object>("gcp.project_id", projectId),
+                    new KeyValuePair<string, object>("project_id", projectId),
+                    new KeyValuePair<string, object>("location", "us-central1"),
+                    new KeyValuePair<string, object>("instance_id", "test-spanner-instance"),
+                    new KeyValuePair<string, object>("instance_config", "unknown"),
+                    new KeyValuePair<string, object>("client_hash", "1234abcd"),
+                ]))
+            .AddGoogleCloudBuiltInMetrics(credential)
+            .Build();
+
+        var meter = new Meter(SpannerMetricsConfiguration.MeterName);
+
+        var operationCounter = meter.CreateCounter<long>("operation_count");
+        var operationLatency = meter.CreateHistogram<double>("operation_latencies");
+        var attemptCounter = meter.CreateCounter<long>("attempt_count");
+        var attemptLatency = meter.CreateHistogram<double>("attempt_latencies");
+        var gfeLatency = meter.CreateHistogram<double>("gfe_latencies");
+        var gfeErrorCounter = meter.CreateCounter<long>("gfe_connectivity_error_count");
+
+        var labels = new KeyValuePair<string, object>[]
+        {
+            new("database", "test-database"),
+            new("method", "ExecuteSql"),
+            new("status", "OK"),
+            new("client_name", testClientName),
+            new("client_uid", testUid),
+            new("directpath_enabled", false),
+            new("directpath_used", false)
+        };
+
+        // Emit all metrics together so they export in a single batch,
+        // running tests individualy would be too slow (1-3 minutes each)
+        for (int i = 0; i < 5; i++)
+        {
+            operationCounter.Add(1, labels);
+            operationLatency.Record(125.0, labels);
+            attemptCounter.Add(1, labels);
+            attemptLatency.Record(80.0, labels);
+            gfeLatency.Record(15.0, labels);
+            gfeErrorCounter.Add(1, labels);
+            await Task.Delay(200);
+        }
+
+        meterProvider.ForceFlush();
+
+        var client = new MetricServiceClientBuilder
+        {
+            Credential = credential
+        }.Build();
+
+        // Ensure all metrics were registered to the spanner built in metrics resource
+        var verificationTasks = s_expectedMetrics.Select(metricType =>
+            WaitForMetricAsync(client, projectId, metricType, testClientName));
+        await Task.WhenAll(verificationTasks);
+    }
+
+    private static async Task WaitForMetricAsync(
+        MetricServiceClient client,
+        string projectId,
+        string metricType,
+        string expectedClientName)
+    {
+        var startTime = DateTime.UtcNow;
+        var deadline = startTime + s_pollingTimeout;
+
+        var request = new ListTimeSeriesRequest
+        {
+            Name = $"projects/{projectId}",
+            Filter = $"metric.type = \"{metricType}\" AND metric.labels.client_name = \"{expectedClientName}\"",
+            Interval = new TimeInterval
+            {
+                StartTime = Timestamp.FromDateTime(startTime.AddMinutes(-5)),
+                EndTime = Timestamp.FromDateTime(startTime.AddMinutes(5))
+            }
+        };
+
+        while (DateTime.UtcNow < deadline)
+        {
+            try
+            {
+                var response = await client.ListTimeSeriesAsync(request).ReadPageAsync(100);
+                if (response.Any(series => series.Points.Count != 0))
+                {
+                    return;
+                }
+            }
+            catch (RpcException ex) when (ex.StatusCode == StatusCode.NotFound || ex.StatusCode == StatusCode.InvalidArgument)
+            {
+                // Metric not yet ingested or indexed
+            }
+
+            await Task.Delay(s_pollingInterval);
+        }
+
+        Assert.Fail($"Timed out waiting {s_pollingTimeout.TotalMinutes} minutes for metric '{metricType}' with client_name='{expectedClientName}' to appear in Cloud Monitoring.");
+    }
+}
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/SpannerMetricsConfigurationTests.cs b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/SpannerMetricsConfigurationTests.cs
new file mode 100644
index 000000000000..0da6c7310c2d
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/SpannerMetricsConfigurationTests.cs
@@ -0,0 +1,102 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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.
+
+using OpenTelemetry;
+using OpenTelemetry.Metrics;
+using System.Collections.Generic;
+using System.Diagnostics.Metrics;
+using Xunit;
+
+namespace Google.Cloud.BuiltInMetrics.Tests;
+
+public class SpannerMetricsConfigurationTests
+{
+    public enum MetricInstrumentType
+    {
+        Counter,
+        Histogram
+    }
+
+    [Theory]
+    [InlineData("operation_count", MetricInstrumentType.Counter)]
+    [InlineData("attempt_count", MetricInstrumentType.Counter)]
+    [InlineData("gfe_connectivity_error_count", MetricInstrumentType.Counter)]
+    [InlineData("afe_connectivity_error_count", MetricInstrumentType.Counter)]
+    [InlineData("operation_latencies", MetricInstrumentType.Histogram)]
+    [InlineData("attempt_latencies", MetricInstrumentType.Histogram)]
+    [InlineData("gfe_latencies", MetricInstrumentType.Histogram)]
+    [InlineData("afe_latencies", MetricInstrumentType.Histogram)]
+    public void Configure_MapsInstrumentsToInternalPrefix(
+        string instrumentName,
+        MetricInstrumentType instrumentType)
+    {
+        var exportedMetrics = new List<Metric>();
+        using var meterProvider = Sdk.CreateMeterProviderBuilder()
+            .AddTestExporter(exportedMetrics)
+            .ConfigureSpannerMetrics()
+            .Build();
+
+        var meter = new Meter(SpannerMetricsConfiguration.MeterName);
+        if (instrumentType == MetricInstrumentType.Counter)
+        {
+            meter.CreateCounter<long>(instrumentName).Add(1);
+        }
+        else
+        {
+            meter.CreateHistogram<double>(instrumentName).Record(1);
+        }
+
+        meterProvider.ForceFlush();
+
+        var metric = Assert.Single(exportedMetrics);
+        // The metrics should have spanner.googleapis.com/internal/client/ as a prefix
+        Assert.Equal(SpannerMetricsConfiguration.InternalMetricPrefix + instrumentName, metric.Name);
+    }
+
+    [Fact]
+    public void Configure_UnregisteredMeter_IsIgnored()
+    {
+        var exportedMetrics = new List<Metric>();
+        using var meterProvider = Sdk.CreateMeterProviderBuilder()
+            .AddTestExporter(exportedMetrics)
+            .ConfigureSpannerMetrics()
+            .Build();
+
+        var unregisteredMeter = new Meter("Some.Other.Unregistered.Meter");
+        unregisteredMeter.CreateCounter<long>("operation_count").Add(10);
+
+        meterProvider.ForceFlush();
+
+        Assert.Empty(exportedMetrics);
+    }
+
+    [Fact]
+    public void Configure_AnotherMeter_IsNotTransformedBySpannerViews()
+    {
+        var exportedMetrics = new List<Metric>();
+        using var meterProvider = Sdk.CreateMeterProviderBuilder()
+            .AddMeter("CustomApp.Meter")
+            .AddTestExporter(exportedMetrics)
+            .ConfigureSpannerMetrics()
+            .Build();
+
+        var customMeter = new Meter("CustomApp.Meter");
+        customMeter.CreateCounter<long>("operation_count").Add(10);
+
+        meterProvider.ForceFlush();
+
+        var metric = Assert.Single(exportedMetrics);
+        Assert.Equal("operation_count", metric.Name);
+    }
+}
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/TestMetricExporter.cs b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/TestMetricExporter.cs
new file mode 100644
index 000000000000..277cdfec8e69
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics.Tests/TestMetricExporter.cs
@@ -0,0 +1,49 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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.
+
+using OpenTelemetry;
+using OpenTelemetry.Metrics;
+using System.Collections.Generic;
+
+namespace Google.Cloud.BuiltInMetrics.Tests;
+
+internal static class TestMeterProviderBuilderExtensions
+{
+    public static MeterProviderBuilder ConfigureSpannerMetrics(this MeterProviderBuilder builder)
+    {
+        SpannerMetricsConfiguration.Instance.Configure(builder);
+        return builder;
+    }
+
+    public static MeterProviderBuilder AddTestExporter(this MeterProviderBuilder builder, List<Metric> exportedMetrics)
+    {
+        return builder.AddReader(new BaseExportingMetricReader(new TestMetricExporter(exportedMetrics)));
+    }
+}
+
+internal class TestMetricExporter : BaseExporter<Metric>
+{
+    private readonly List<Metric> _metrics;
+
+    public TestMetricExporter(List<Metric> metrics) => _metrics = metrics;
+
+    public override ExportResult Export(in Batch<Metric> batch)
+    {
+        foreach (var metric in batch)
+        {
+            _metrics.Add(metric);
+        }
+        return ExportResult.Success;
+    }
+}
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/AssemblyInfo.cs b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/AssemblyInfo.cs
new file mode 100644
index 000000000000..c02fe2da3333
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/AssemblyInfo.cs
@@ -0,0 +1,31 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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.
+
+using System.Runtime.CompilerServices;
+
+[assembly: InternalsVisibleTo("Google.Cloud.BuiltInMetrics.IntegrationTests, PublicKey="
+                              + "0024000004800000940000000602000000240000525341310004000001000100afab79952ee222"
+                              + "15f12b4e09337e65509c943fbc22d7006bc371d581d0f0ebf0da5d8039aab2607fb68a138a5d80"
+                              + "a71bc02b7ebf586dbe1f2493c0ab20423ababfd15ce74d2264a6b37745f3658f016abaad662182"
+                              + "aaef634a60f1346fcc45343acab5b6781535a3134818e13fac895a6c106c0480e34bbb06cb123e"
+                              + "5583d8d2"
+)]
+
+[assembly: InternalsVisibleTo("Google.Cloud.BuiltInMetrics.Tests, PublicKey="
+                              + "0024000004800000940000000602000000240000525341310004000001000100afab79952ee222"
+                              + "15f12b4e09337e65509c943fbc22d7006bc371d581d0f0ebf0da5d8039aab2607fb68a138a5d80"
+                              + "a71bc02b7ebf586dbe1f2493c0ab20423ababfd15ce74d2264a6b37745f3658f016abaad662182"
+                              + "aaef634a60f1346fcc45343acab5b6781535a3134818e13fac895a6c106c0480e34bbb06cb123e"
+                              + "5583d8d2"
+)]
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/BuiltInMetrics.cs b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/BuiltInMetrics.cs
new file mode 100644
index 000000000000..4686db6c870a
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/BuiltInMetrics.cs
@@ -0,0 +1,156 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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.
+
+using Google.Api.Gax;
+using Google.Apis.Auth.OAuth2;
+using OpenTelemetry;
+using OpenTelemetry.Exporter;
+using OpenTelemetry.Metrics;
+using System;
+using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Google.Cloud.BuiltInMetrics;
+
+/// <summary>
+/// Entry point for enabling and exporting Google Cloud client built-in metrics telemetry.
+/// </summary>
+public static class BuiltInMetrics
+{
+    private static readonly Uri s_metricsEndpoint = new("https://telemetry.googleapis.com/v1/metrics");
+    // The minimal privelaged auth scope required to emit telmemetry
+    private const string MonitoringAuthScope = "https://www.googleapis.com/auth/monitoring.write";
+
+    /// <summary>
+    /// Enables Google Cloud client built-in metrics collection and starts exporting telemetry to Google Cloud Monitoring.
+    /// </summary>
+    /// <param name="credential">Optional Google credential. If null, Application Default Credentials (ADC) will be used.</param>
+    /// <returns>An <see cref="IDisposable"/> session. Disposing it flushes pending telemetry and stops collection.</returns>
+    public static IDisposable Enable(GoogleCredential credential = null)
+    {
+        var meterProvider = Sdk.CreateMeterProviderBuilder()
+            .AddGoogleCloudBuiltInMetrics(credential)
+            .Build();
+        return new BuiltInMetricsSession(meterProvider);
+    }
+
+    /// <summary>
+    /// Asynchronously enables Google Cloud client built-in metrics collection and starts exporting telemetry to Google Cloud Monitoring.
+    /// </summary>
+    /// <param name="credential">Optional Google credential. If null, Application Default Credentials (ADC) will be used.</param>
+    /// <param name="cancellationToken">Cancellation token for credential resolution.</param>
+    /// <returns>A task returning an <see cref="IDisposable"/> session. Disposing it flushes pending telemetry and stops collection.</returns>
+    public static async Task<IDisposable> EnableAsync(GoogleCredential credential = null, CancellationToken cancellationToken = default)
+    {
+        var builder = Sdk.CreateMeterProviderBuilder();
+        await builder.AddGoogleCloudBuiltInMetricsAsync(credential, cancellationToken).ConfigureAwait(false);
+        return new BuiltInMetricsSession(builder.Build());
+    }
+
+    /// <summary>
+    /// Helper method to configure an existing <see cref="MeterProviderBuilder"/> with the Google Cloud built-in metrics OTLP exporter.
+    /// </summary>
+    internal static MeterProviderBuilder AddGoogleCloudBuiltInMetrics(
+        this MeterProviderBuilder builder,
+        GoogleCredential credential = null)
+    {
+        GaxPreconditions.CheckNotNull(builder, nameof(builder));
+        return ConfigureOtlpExporter(builder, GetDefaultCredential(credential));
+    }
+
+    /// <summary>
+    /// Helper method to configure an existing <see cref="MeterProviderBuilder"/> with the Google Cloud built-in metrics OTLP exporter.
+    /// </summary>
+    internal static async Task<MeterProviderBuilder> AddGoogleCloudBuiltInMetricsAsync(
+        this MeterProviderBuilder builder,
+        GoogleCredential credential = null,
+        CancellationToken cancellationToken = default)
+    {
+        GaxPreconditions.CheckNotNull(builder, nameof(builder));
+        var resolvedCredential = await GetDefaultCredentialAsync(credential, cancellationToken).ConfigureAwait(false);
+        return ConfigureOtlpExporter(builder, resolvedCredential);
+    }
+
+    private static MeterProviderBuilder ConfigureOtlpExporter(MeterProviderBuilder builder, GoogleCredential credential)
+    {
+        SpannerMetricsConfiguration.Instance.Configure(builder);
+        return builder.AddOtlpExporter(exporterOptions =>
+        {
+            exporterOptions.Endpoint = s_metricsEndpoint;
+            exporterOptions.Protocol = OtlpExportProtocol.HttpProtobuf;
+            exporterOptions.HttpClientFactory = () => new HttpClient(new AuthHeaderHandler(credential));
+        });
+    }
+
+    private static GoogleCredential GetDefaultCredential(GoogleCredential credential)
+    {
+        credential ??= GoogleCredential.GetApplicationDefault();
+        if (credential.IsCreateScopedRequired)
+        {
+            // We attach the required monitoring scope if the provided credential has no scope such as in the case of ADC.
+            credential = credential.CreateScoped(MonitoringAuthScope);
+        }
+        return credential;
+    }
+
+    private static async Task<GoogleCredential> GetDefaultCredentialAsync(GoogleCredential credential, CancellationToken cancellationToken)
+    {
+        credential ??= await GoogleCredential.GetApplicationDefaultAsync(cancellationToken).ConfigureAwait(false);
+        if (credential.IsCreateScopedRequired)
+        {
+            credential = credential.CreateScoped(MonitoringAuthScope);
+        }
+        return credential;
+    }
+
+    /// <summary>
+    /// Attaches a Bearer token to outbound requests. This is required because the OTLP
+    /// metrics endpoint requires Bearer token authorization and tokens must be dynamically refreshed as they expire.
+    /// </summary>
+    private sealed class AuthHeaderHandler : DelegatingHandler
+    {
+        private readonly GoogleCredential _credential;
+
+        public AuthHeaderHandler(GoogleCredential credential)
+        {
+            _credential = GaxPreconditions.CheckNotNull(credential, nameof(credential));
+            InnerHandler = new HttpClientHandler();
+        }
+
+        protected override async Task<HttpResponseMessage> SendAsync(
+            HttpRequestMessage request,
+            CancellationToken cancellationToken)
+        {
+            string accessToken = await ((ITokenAccess)_credential).GetAccessTokenForRequestAsync(cancellationToken: cancellationToken).ConfigureAwait(false);
+            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
+            return await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
+        }
+    }
+
+    /// <summary>
+    /// Restricts the underlying <see cref="MeterProvider"/> to only expose <see cref="IDisposable"/>.
+    /// This is required to prevent callers from directly manipulating or misconfiguring the provider while still allowing them to flush and stop collection.
+    /// </summary>
+    internal sealed class BuiltInMetricsSession : IDisposable
+    {
+        internal MeterProvider MeterProvider { get; }
+
+        public BuiltInMetricsSession(MeterProvider meterProvider) =>
+            MeterProvider = GaxPreconditions.CheckNotNull(meterProvider, nameof(meterProvider));
+
+        public void Dispose() => MeterProvider.Dispose();
+    }
+}
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/IServiceMetricsConfiguration.cs b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/IServiceMetricsConfiguration.cs
new file mode 100644
index 000000000000..d43bcb9840e0
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/IServiceMetricsConfiguration.cs
@@ -0,0 +1,29 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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.
+
+using OpenTelemetry.Metrics;
+
+namespace Google.Cloud.BuiltInMetrics;
+
+/// <summary>
+/// Defines service-specific metrics configuration for OpenTelemetry collection.
+/// </summary>
+internal interface IServiceMetricsConfiguration
+{
+    /// <summary>
+    /// Configures meters, views, and instruments for the service.
+    /// </summary>
+    /// <param name="builder">The meter provider builder to configure.</param>
+    void Configure(MeterProviderBuilder builder);
+}
diff --git a/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/SpannerMetricsConfiguration.cs b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/SpannerMetricsConfiguration.cs
new file mode 100644
index 000000000000..a462146c3684
--- /dev/null
+++ b/apis/Google.Cloud.BuiltInMetrics/Google.Cloud.BuiltInMetrics/SpannerMetricsConfiguration.cs
@@ -0,0 +1,96 @@
+// Copyright 2026 Google LLC
+//
+// 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
+//
+//     https://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.
+
+using Google.Api.Gax;
+using OpenTelemetry.Metrics;
+using System.Linq;
+
+namespace Google.Cloud.BuiltInMetrics;
+
+/// <summary>
+/// Configuration for Google Cloud Spanner built-in metrics telemetry.
+/// </summary>
+internal sealed class SpannerMetricsConfiguration : IServiceMetricsConfiguration
+{
+    /// <summary>
+    /// The singleton instance of <see cref="SpannerMetricsConfiguration"/>.
+    /// </summary>
+    internal static SpannerMetricsConfiguration Instance { get; } = new SpannerMetricsConfiguration();
+
+    /// <summary>
+    /// The meter name used for Spanner client telemetry.
+    /// </summary>
+    internal const string MeterName = "Google.Cloud.Spanner.BuiltInMetrics";
+
+    /// <summary>
+    /// The internal metric prefix required for GCP Monitoring OTLP ingestion.
+    /// </summary>
+    internal const string InternalMetricPrefix = "spanner.googleapis.com/internal/client/";
+
+    /// <summary>
+    /// Default explicit histogram bucket boundaries (in milliseconds) for Spanner latency metrics.
+    /// </summary>
+    private static readonly double[] DefaultHistogramBoundaries = [10.0, 50.0, 100.0, 250.0, 500.0, 1000.0];
+
+    private static readonly string[] s_counterInstruments =
+    [
+        "operation_count",
+        "attempt_count",
+        "gfe_connectivity_error_count",
+        "afe_connectivity_error_count"
+    ];
+
+    private static readonly string[] s_latencyInstruments =
+    [
+        "operation_latencies",
+        "attempt_latencies",
+        "gfe_latencies",
+        "afe_latencies"
+    ];
+
+    /// <inheritdoc/>
+    public void Configure(MeterProviderBuilder builder)
+    {
+        GaxPreconditions.CheckNotNull(builder, nameof(builder));
+
+        builder.AddMeter(MeterName);
+
+        builder.AddView(instrument =>
+        {
+            if (instrument.Meter.Name != MeterName)
+            {
+                return null;
+            }
+
+            if (s_counterInstruments.Contains(instrument.Name))
+            {
+                return new MetricStreamConfiguration
+                {
+                    Name = InternalMetricPrefix + instrument.Name
+                };
+            }
+
+            if (s_latencyInstruments.Contains(instrument.Name))
+            {
+                return new ExplicitBucketHistogramConfiguration
+                {
+                    Name = InternalMetricPrefix + instrument.Name,
+                    Boundaries = DefaultHistogramBoundaries
+                };
+            }
+
+            return null;
+        });
+    }
+}