diff --git a/google/cloud/bigtable/internal/client_schema_metrics_test.cc b/google/cloud/bigtable/internal/client_schema_metrics_test.cc
index ce95e16c2541d..835060d7b5da4 100644
--- a/google/cloud/bigtable/internal/client_schema_metrics_test.cc
+++ b/google/cloud/bigtable/internal/client_schema_metrics_test.cc
@@ -20,10 +20,10 @@
 #include "google/cloud/bigtable/internal/client_schema_metrics.h"
 #include "google/cloud/bigtable/options.h"
 #include "google/cloud/bigtable/version.h"
+#include "google/cloud/testing_util/mock_opentelemetry_metrics.h"
+#include "google/cloud/testing_util/opentelemetry_attributes.h"
 #include <gmock/gmock.h>
 #include <opentelemetry/context/runtime_context.h>
-#include <opentelemetry/metrics/async_instruments.h>
-#include <opentelemetry/metrics/meter.h>
 
 namespace google {
 namespace cloud {
@@ -31,198 +31,16 @@ namespace bigtable_internal {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 namespace {
 
+using ::google::cloud::testing_util::MakeAttributesMap;
+using ::google::cloud::testing_util::MockHistogram;
+using ::google::cloud::testing_util::MockMeter;
+using ::google::cloud::testing_util::MockMeterProvider;
 using ::testing::A;
 using ::testing::Eq;
 using ::testing::IsEmpty;
 using ::testing::Pair;
 using ::testing::UnorderedElementsAre;
 
-using ::opentelemetry::metrics::Counter;
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-using ::opentelemetry::metrics::Gauge;
-#endif
-using ::opentelemetry::metrics::Histogram;
-using ::opentelemetry::metrics::ObservableInstrument;
-using ::opentelemetry::metrics::UpDownCounter;
-
-template <typename T>
-class MockHistogram : public opentelemetry::metrics::Histogram<T> {
- public:
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T value), (noexcept, override));
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T, opentelemetry::common::KeyValueIterable const&),
-              (noexcept, override));
-
-#endif
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T value, opentelemetry::context::Context const& context),
-              (noexcept, override));
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T value,
-               opentelemetry::common::KeyValueIterable const& attributes,
-               opentelemetry::context::Context const& context),
-              (noexcept, override));
-};
-
-class MockMeter : public opentelemetry::metrics::Meter {
- public:
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Counter<uint64_t>>,
-              CreateUInt64Counter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Counter<double>>,
-              CreateDoubleCounter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateInt64ObservableCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateDoubleObservableCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Histogram<uint64_t>>,
-              CreateUInt64Histogram,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Histogram<double>>,
-              CreateDoubleHistogram,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Gauge<int64_t>>,
-              CreateInt64Gauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Gauge<double>>,
-              CreateDoubleGauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(uintptr_t,
-              RegisterCallback,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::metrics::MultiObservableCallbackPtr, void*,
-               opentelemetry::nostd::span<
-                   opentelemetry::metrics::ObservableInstrument*>),
-              (noexcept, override));
-
-  MOCK_METHOD(void,
-              DeregisterCallback,  // NOLINT(bugprone-exception-escape)
-              (uintptr_t), (noexcept, override));
-#endif
-
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-              CreateInt64ObservableGauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-              CreateDoubleObservableGauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<UpDownCounter<int64_t>>,
-              CreateInt64UpDownCounter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<UpDownCounter<double>>,
-              CreateDoubleUpDownCounter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateInt64ObservableUpDownCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateDoubleObservableUpDownCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-};
-
-class MockMeterProvider : public opentelemetry::metrics::MeterProvider {
- public:
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter>,
-              GetMeter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::common::KeyValueIterable const*),
-              (noexcept, override));
-
-  MOCK_METHOD(void, RemoveMeter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-#else
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter>,
-              GetMeter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-#endif
-};
-
-std::unordered_map<std::string, std::string> MakeAttributesMap(
-    opentelemetry::common::KeyValueIterable const& attributes) {
-  std::unordered_map<std::string, std::string> m;
-  attributes.ForEachKeyValue([&](opentelemetry::nostd::string_view k,
-                                 opentelemetry::common::AttributeValue v) {
-    if (opentelemetry::nostd::holds_alternative<
-            opentelemetry::nostd::string_view>(v)) {
-      m.emplace(
-          std::string{k},
-          opentelemetry::nostd::get<opentelemetry::nostd::string_view>(v));
-    }
-    return true;
-  });
-  return m;
-}
-
 TEST(ClientSchemaMetricsTest, IntoLabelMapClient) {
   ClientResourceLabels resource{"p-1",    "i-1",       "app-1", "client-1",
                                 "uid-1",  "cp-1",      "loc-1", "cloud-1",
diff --git a/google/cloud/bigtable/internal/table_schema_metrics_test.cc b/google/cloud/bigtable/internal/table_schema_metrics_test.cc
index 66840f990ba0e..849b282d688cd 100644
--- a/google/cloud/bigtable/internal/table_schema_metrics_test.cc
+++ b/google/cloud/bigtable/internal/table_schema_metrics_test.cc
@@ -21,6 +21,8 @@
 #include "google/cloud/bigtable/options.h"
 #include "google/cloud/bigtable/version.h"
 #include "google/cloud/testing_util/fake_clock.h"
+#include "google/cloud/testing_util/mock_opentelemetry_metrics.h"
+#include "google/cloud/testing_util/opentelemetry_attributes.h"
 #include "google/cloud/testing_util/validate_metadata.h"
 #include "absl/strings/escaping.h"
 #include "google/bigtable/v2/peer_info.pb.h"
@@ -34,6 +36,11 @@ GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 namespace {
 
 using ::google::cloud::testing_util::FakeSteadyClock;
+using ::google::cloud::testing_util::MakeAttributesMap;
+using ::google::cloud::testing_util::MockCounter;
+using ::google::cloud::testing_util::MockHistogram;
+using ::google::cloud::testing_util::MockMeter;
+using ::google::cloud::testing_util::MockMeterProvider;
 using ::google::cloud::testing_util::SetServerMetadata;
 
 using ::testing::A;
@@ -41,193 +48,6 @@ using ::testing::Eq;
 using ::testing::Pair;
 using ::testing::UnorderedElementsAre;
 
-using ::opentelemetry::metrics::Counter;
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-using ::opentelemetry::metrics::Gauge;
-#endif
-using ::opentelemetry::metrics::Histogram;
-using ::opentelemetry::metrics::ObservableInstrument;
-using ::opentelemetry::metrics::UpDownCounter;
-
-template <typename T>
-class MockHistogram : public opentelemetry::metrics::Histogram<T> {
- public:
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T value), (noexcept, override));
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T, opentelemetry::common::KeyValueIterable const&),
-              (noexcept, override));
-
-#endif
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T value, opentelemetry::context::Context const& context),
-              (noexcept, override));
-  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
-              (T value,
-               opentelemetry::common::KeyValueIterable const& attributes,
-               opentelemetry::context::Context const& context),
-              (noexcept, override));
-};
-
-template <typename T>
-class MockCounter : public opentelemetry::metrics::Counter<T> {
- public:
-  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
-              (T value), (noexcept, override));
-  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
-              (T value, opentelemetry::context::Context const&),
-              (noexcept, override));
-  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
-              (T value, opentelemetry::common::KeyValueIterable const&),
-              (noexcept, override));
-  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
-              (T value, opentelemetry::common::KeyValueIterable const&,
-               opentelemetry::context::Context const&),
-              (noexcept, override));
-};
-
-class MockMeter : public opentelemetry::metrics::Meter {
- public:
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Counter<uint64_t>>,
-              CreateUInt64Counter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Counter<double>>,
-              CreateDoubleCounter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateInt64ObservableCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateDoubleObservableCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Histogram<uint64_t>>,
-              CreateUInt64Histogram,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Histogram<double>>,
-              CreateDoubleHistogram,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Gauge<int64_t>>,
-              CreateInt64Gauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<Gauge<double>>,
-              CreateDoubleGauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(uintptr_t,
-              RegisterCallback,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::metrics::MultiObservableCallbackPtr, void*,
-               opentelemetry::nostd::span<
-                   opentelemetry::metrics::ObservableInstrument*>),
-              (noexcept, override));
-
-  MOCK_METHOD(void,
-              DeregisterCallback,  // NOLINT(bugprone-exception-escape)
-              (uintptr_t), (noexcept, override));
-#endif
-
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-              CreateInt64ObservableGauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-              CreateDoubleObservableGauge,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<UpDownCounter<int64_t>>,
-              CreateInt64UpDownCounter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(opentelemetry::nostd::unique_ptr<UpDownCounter<double>>,
-              CreateDoubleUpDownCounter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateInt64ObservableUpDownCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-
-  MOCK_METHOD(
-      opentelemetry::nostd::shared_ptr<ObservableInstrument>,
-      CreateDoubleObservableUpDownCounter,  // NOLINT(bugprone-exception-escape)
-      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
-       opentelemetry::nostd::string_view),
-      (noexcept, override));
-};
-
-class MockMeterProvider : public opentelemetry::metrics::MeterProvider {
- public:
-#if OPENTELEMETRY_ABI_VERSION_NO >= 2
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter>,
-              GetMeter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::common::KeyValueIterable const*),
-              (noexcept, override));
-
-  MOCK_METHOD(void, RemoveMeter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-
-#else
-  MOCK_METHOD(opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter>,
-              GetMeter,  // NOLINT(bugprone-exception-escape)
-              (opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view,
-               opentelemetry::nostd::string_view),
-              (noexcept, override));
-#endif
-};
-
 TEST(LabelMap, IntoLabelMap) {
   TableResourceLabels r{"my-project", "my-instance", "my-table", "my-cluster",
                         "my-zone"};
@@ -438,22 +258,6 @@ TEST(GetPeerInfoFromMetadata, InvalidBase64Trailers) {
   }
 }
 
-std::unordered_map<std::string, std::string> MakeAttributesMap(
-    opentelemetry::common::KeyValueIterable const& attributes) {
-  std::unordered_map<std::string, std::string> m;
-  attributes.ForEachKeyValue([&](opentelemetry::nostd::string_view k,
-                                 opentelemetry::common::AttributeValue v) {
-    if (opentelemetry::nostd::holds_alternative<
-            opentelemetry::nostd::string_view>(v)) {
-      m.emplace(
-          std::string{k},
-          opentelemetry::nostd::get<opentelemetry::nostd::string_view>(v));
-    }
-    return true;
-  });
-  return m;
-}
-
 void SetClusterZone(grpc::ClientContext& client_context) {
   CreateServerMetadata(client_context,
                        CreateServerMetadataOptions{false, true});
diff --git a/google/cloud/testing_util/CMakeLists.txt b/google/cloud/testing_util/CMakeLists.txt
index 1a4d1cc1bb20f..0ff9e28efc320 100644
--- a/google/cloud/testing_util/CMakeLists.txt
+++ b/google/cloud/testing_util/CMakeLists.txt
@@ -40,6 +40,9 @@ add_library(
     mock_backoff_policy.h
     mock_fake_clock.cc
     mock_fake_clock.h
+    mock_opentelemetry_metrics.h
+    opentelemetry_attributes.cc
+    opentelemetry_attributes.h
     opentelemetry_matchers.cc
     opentelemetry_matchers.h
     scoped_environment.cc
diff --git a/google/cloud/testing_util/google_cloud_cpp_testing.bzl b/google/cloud/testing_util/google_cloud_cpp_testing.bzl
index 8f9de55ad2254..78c1f37b14c75 100644
--- a/google/cloud/testing_util/google_cloud_cpp_testing.bzl
+++ b/google/cloud/testing_util/google_cloud_cpp_testing.bzl
@@ -32,6 +32,8 @@ google_cloud_cpp_testing_hdrs = [
     "mock_async_streaming_write_rpc.h",
     "mock_backoff_policy.h",
     "mock_fake_clock.h",
+    "mock_opentelemetry_metrics.h",
+    "opentelemetry_attributes.h",
     "opentelemetry_matchers.h",
     "scoped_environment.h",
     "scoped_log.h",
@@ -47,6 +49,7 @@ google_cloud_cpp_testing_srcs = [
     "example_driver.cc",
     "integration_test.cc",
     "mock_fake_clock.cc",
+    "opentelemetry_attributes.cc",
     "opentelemetry_matchers.cc",
     "scoped_environment.cc",
     "scoped_log.cc",
diff --git a/google/cloud/testing_util/mock_opentelemetry_metrics.h b/google/cloud/testing_util/mock_opentelemetry_metrics.h
new file mode 100644
index 0000000000000..0f838628c376b
--- /dev/null
+++ b/google/cloud/testing_util/mock_opentelemetry_metrics.h
@@ -0,0 +1,233 @@
+// 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.
+
+#ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_TESTING_UTIL_MOCK_OPENTELEMETRY_METRICS_H
+#define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_TESTING_UTIL_MOCK_OPENTELEMETRY_METRICS_H
+
+#include "google/cloud/version.h"
+#include <gmock/gmock.h>
+#include <opentelemetry/common/key_value_iterable.h>
+#include <opentelemetry/context/context.h>
+#include <opentelemetry/metrics/async_instruments.h>
+#include <opentelemetry/metrics/meter.h>
+#include <opentelemetry/metrics/meter_provider.h>
+#include <opentelemetry/metrics/sync_instruments.h>
+#include <opentelemetry/nostd/shared_ptr.h>
+#include <opentelemetry/nostd/span.h>
+#include <opentelemetry/nostd/string_view.h>
+#include <opentelemetry/nostd/unique_ptr.h>
+#include <opentelemetry/version.h>
+#include <cstdint>
+
+namespace google {
+namespace cloud {
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+namespace testing_util {
+
+template <typename T>
+class MockHistogram : public opentelemetry::metrics::Histogram<T> {
+ public:
+#if OPENTELEMETRY_ABI_VERSION_NO >= 2
+  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
+              (T value), (noexcept, override));
+  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
+              (T, opentelemetry::common::KeyValueIterable const&),
+              (noexcept, override));
+
+#endif
+  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
+              (T value, opentelemetry::context::Context const& context),
+              (noexcept, override));
+  MOCK_METHOD(void, Record,  // NOLINT(bugprone-exception-escape)
+              (T value,
+               opentelemetry::common::KeyValueIterable const& attributes,
+               opentelemetry::context::Context const& context),
+              (noexcept, override));
+};
+
+template <typename T>
+class MockCounter : public opentelemetry::metrics::Counter<T> {
+ public:
+  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
+              (T value), (noexcept, override));
+  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
+              (T value, opentelemetry::context::Context const&),
+              (noexcept, override));
+  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
+              (T value, opentelemetry::common::KeyValueIterable const&),
+              (noexcept, override));
+  MOCK_METHOD(void, Add,  // NOLINT(bugprone-exception-escape)
+              (T value, opentelemetry::common::KeyValueIterable const&,
+               opentelemetry::context::Context const&),
+              (noexcept, override));
+};
+
+class MockMeter : public opentelemetry::metrics::Meter {
+ public:
+  MOCK_METHOD(opentelemetry::nostd::unique_ptr<
+                  opentelemetry::metrics::Counter<uint64_t>>,
+              CreateUInt64Counter,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+  MOCK_METHOD(
+      opentelemetry::nostd::unique_ptr<opentelemetry::metrics::Counter<double>>,
+      CreateDoubleCounter,  // NOLINT(bugprone-exception-escape)
+      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
+       opentelemetry::nostd::string_view),
+      (noexcept, override));
+
+  MOCK_METHOD(
+      opentelemetry::nostd::shared_ptr<
+          opentelemetry::metrics::ObservableInstrument>,
+      CreateInt64ObservableCounter,  // NOLINT(bugprone-exception-escape)
+      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
+       opentelemetry::nostd::string_view),
+      (noexcept, override));
+
+  MOCK_METHOD(
+      opentelemetry::nostd::shared_ptr<
+          opentelemetry::metrics::ObservableInstrument>,
+      CreateDoubleObservableCounter,  // NOLINT(bugprone-exception-escape)
+      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
+       opentelemetry::nostd::string_view),
+      (noexcept, override));
+
+  MOCK_METHOD(opentelemetry::nostd::unique_ptr<
+                  opentelemetry::metrics::Histogram<uint64_t>>,
+              CreateUInt64Histogram,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+  MOCK_METHOD(opentelemetry::nostd::unique_ptr<
+                  opentelemetry::metrics::Histogram<double>>,
+              CreateDoubleHistogram,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+#if OPENTELEMETRY_ABI_VERSION_NO >= 2
+  MOCK_METHOD(
+      opentelemetry::nostd::unique_ptr<opentelemetry::metrics::Gauge<int64_t>>,
+      CreateInt64Gauge,  // NOLINT(bugprone-exception-escape)
+      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
+       opentelemetry::nostd::string_view),
+      (noexcept, override));
+
+  MOCK_METHOD(
+      opentelemetry::nostd::unique_ptr<opentelemetry::metrics::Gauge<double>>,
+      CreateDoubleGauge,  // NOLINT(bugprone-exception-escape)
+      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
+       opentelemetry::nostd::string_view),
+      (noexcept, override));
+
+  MOCK_METHOD(uintptr_t,
+              RegisterCallback,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::metrics::MultiObservableCallbackPtr, void*,
+               opentelemetry::nostd::span<
+                   opentelemetry::metrics::ObservableInstrument*>),
+              (noexcept, override));
+
+  MOCK_METHOD(void,
+              DeregisterCallback,  // NOLINT(bugprone-exception-escape)
+              (uintptr_t), (noexcept, override));
+#endif
+
+  MOCK_METHOD(opentelemetry::nostd::shared_ptr<
+                  opentelemetry::metrics::ObservableInstrument>,
+              CreateInt64ObservableGauge,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+  MOCK_METHOD(opentelemetry::nostd::shared_ptr<
+                  opentelemetry::metrics::ObservableInstrument>,
+              CreateDoubleObservableGauge,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+  MOCK_METHOD(opentelemetry::nostd::unique_ptr<
+                  opentelemetry::metrics::UpDownCounter<int64_t>>,
+              CreateInt64UpDownCounter,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+  MOCK_METHOD(opentelemetry::nostd::unique_ptr<
+                  opentelemetry::metrics::UpDownCounter<double>>,
+              CreateDoubleUpDownCounter,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+  MOCK_METHOD(
+      opentelemetry::nostd::shared_ptr<
+          opentelemetry::metrics::ObservableInstrument>,
+      CreateInt64ObservableUpDownCounter,  // NOLINT(bugprone-exception-escape)
+      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
+       opentelemetry::nostd::string_view),
+      (noexcept, override));
+
+  MOCK_METHOD(
+      opentelemetry::nostd::shared_ptr<
+          opentelemetry::metrics::ObservableInstrument>,
+      CreateDoubleObservableUpDownCounter,  // NOLINT(bugprone-exception-escape)
+      (opentelemetry::nostd::string_view, opentelemetry::nostd::string_view,
+       opentelemetry::nostd::string_view),
+      (noexcept, override));
+};
+
+class MockMeterProvider : public opentelemetry::metrics::MeterProvider {
+ public:
+#if OPENTELEMETRY_ABI_VERSION_NO >= 2
+  MOCK_METHOD(opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter>,
+              GetMeter,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::common::KeyValueIterable const*),
+              (noexcept, override));
+
+  MOCK_METHOD(void, RemoveMeter,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+
+#else
+  MOCK_METHOD(opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter>,
+              GetMeter,  // NOLINT(bugprone-exception-escape)
+              (opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view,
+               opentelemetry::nostd::string_view),
+              (noexcept, override));
+#endif
+};
+
+}  // namespace testing_util
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
+}  // namespace cloud
+}  // namespace google
+
+#endif  // GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_TESTING_UTIL_MOCK_OPENTELEMETRY_METRICS_H
diff --git a/google/cloud/testing_util/opentelemetry_attributes.cc b/google/cloud/testing_util/opentelemetry_attributes.cc
new file mode 100644
index 0000000000000..2e6e0db56afbb
--- /dev/null
+++ b/google/cloud/testing_util/opentelemetry_attributes.cc
@@ -0,0 +1,44 @@
+// 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.
+
+#include "google/cloud/testing_util/opentelemetry_attributes.h"
+#include <opentelemetry/common/attribute_value.h>
+#include <opentelemetry/nostd/string_view.h>
+#include <opentelemetry/nostd/variant.h>
+
+namespace google {
+namespace cloud {
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+namespace testing_util {
+
+std::unordered_map<std::string, std::string> MakeAttributesMap(
+    opentelemetry::common::KeyValueIterable const& attributes) {
+  std::unordered_map<std::string, std::string> m;
+  attributes.ForEachKeyValue([&](opentelemetry::nostd::string_view k,
+                                 opentelemetry::common::AttributeValue v) {
+    if (opentelemetry::nostd::holds_alternative<
+            opentelemetry::nostd::string_view>(v)) {
+      m.emplace(
+          std::string{k},
+          opentelemetry::nostd::get<opentelemetry::nostd::string_view>(v));
+    }
+    return true;
+  });
+  return m;
+}
+
+}  // namespace testing_util
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
+}  // namespace cloud
+}  // namespace google
diff --git a/google/cloud/testing_util/opentelemetry_attributes.h b/google/cloud/testing_util/opentelemetry_attributes.h
new file mode 100644
index 0000000000000..d71da537ca088
--- /dev/null
+++ b/google/cloud/testing_util/opentelemetry_attributes.h
@@ -0,0 +1,36 @@
+// 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.
+
+#ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_TESTING_UTIL_OPENTELEMETRY_ATTRIBUTES_H
+#define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_TESTING_UTIL_OPENTELEMETRY_ATTRIBUTES_H
+
+#include "google/cloud/version.h"
+#include <opentelemetry/common/key_value_iterable.h>
+#include <string>
+#include <unordered_map>
+
+namespace google {
+namespace cloud {
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+namespace testing_util {
+
+std::unordered_map<std::string, std::string> MakeAttributesMap(
+    opentelemetry::common::KeyValueIterable const& attributes);
+
+}  // namespace testing_util
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
+}  // namespace cloud
+}  // namespace google
+
+#endif  // GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_TESTING_UTIL_OPENTELEMETRY_ATTRIBUTES_H