diff --git a/chrome/browser/ai/ai_manager.cc b/chrome/browser/ai/ai_manager.cc
index 2aa5ee4..e629c596 100644
--- a/chrome/browser/ai/ai_manager.cc
+++ b/chrome/browser/ai/ai_manager.cc
@@ -687,9 +687,25 @@
   receivers_.Add(this, std::move(receiver));
 }
 
+bool AIManager::IsPromptApiEnabled() const {
+  if (base::FeatureList::IsEnabled(blink::features::kAIPromptAPI)) {
+    return true;
+  }
+  if (base::FeatureList::IsEnabled(
+          blink::features::kAIPromptAPIMultimodalInput)) {
+    return true;
+  }
+  return false;
+}
+
 void AIManager::CanCreateLanguageModel(
     blink::mojom::AILanguageModelCreateOptionsPtr options,
     CanCreateLanguageModelCallback callback) {
+  if (!IsPromptApiEnabled()) {
+    std::move(callback).Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled);
+    return;
+  }
   if (IsPermissionsPolicyBlocked(
           network::mojom::PermissionsPolicyFeature::kLanguageModel)) {
     receivers_.ReportBadMessage("Permissions policy disabled");
@@ -758,6 +774,10 @@
     blink::mojom::AILanguageModelCreateOptionsPtr options,
     mojo::PendingRemote<on_device_model::mojom::DownloadObserver> monitor) {
   CHECK(options);
+  if (!IsPromptApiEnabled()) {
+    receivers_.ReportBadMessage("Feature not enabled");
+    return;
+  }
   if (IsBlocked(network::mojom::PermissionsPolicyFeature::kLanguageModel)) {
     receivers_.ReportBadMessage("Policy or user setting disabled");
     return;
@@ -936,6 +956,11 @@
 void AIManager::CanCreateSummarizer(
     blink::mojom::AISummarizerCreateOptionsPtr options,
     CanCreateSummarizerCallback callback) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAISummarizationAPI)) {
+    std::move(callback).Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled);
+    return;
+  }
   if (IsPermissionsPolicyBlocked(
           network::mojom::PermissionsPolicyFeature::kSummarizer)) {
     receivers_.ReportBadMessage("Permissions policy disabled");
@@ -989,6 +1014,10 @@
     mojo::PendingRemote<blink::mojom::AIManagerCreateSummarizerClient> client,
     blink::mojom::AISummarizerCreateOptionsPtr options,
     mojo::PendingRemote<on_device_model::mojom::DownloadObserver> monitor) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAISummarizationAPI)) {
+    receivers_.ReportBadMessage("Feature not enabled");
+    return;
+  }
   if (IsBlocked(network::mojom::PermissionsPolicyFeature::kSummarizer)) {
     receivers_.ReportBadMessage("Policy or user setting disabled");
     return;
@@ -1103,6 +1132,11 @@
 void AIManager::CanCreateProofreader(
     blink::mojom::AIProofreaderCreateOptionsPtr options,
     CanCreateProofreaderCallback callback) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAIProofreadingAPI)) {
+    std::move(callback).Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled);
+    return;
+  }
   // TODO(crbug.com/466425250): Enforce permissions policy.
   // TODO(crbug.com/424673180): Add a warning message when options
   // `includeCorrectionTypes` and `includeCorrectionExplanations` are set to
@@ -1126,6 +1160,10 @@
     mojo::PendingRemote<blink::mojom::AIManagerCreateProofreaderClient> client,
     blink::mojom::AIProofreaderCreateOptionsPtr options,
     mojo::PendingRemote<on_device_model::mojom::DownloadObserver> monitor) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAIProofreadingAPI)) {
+    receivers_.ReportBadMessage("Feature not enabled");
+    return;
+  }
   // TODO(crbug.com/466425250): Enforce permissions policy.
   if (IsBlocked()) {
     receivers_.ReportBadMessage("Policy or user setting disabled");
@@ -1234,6 +1272,11 @@
 
 void AIManager::CanCreateWriter(blink::mojom::AIWriterCreateOptionsPtr options,
                                 CanCreateWriterCallback callback) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAIWriterAPI)) {
+    std::move(callback).Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled);
+    return;
+  }
   if (IsPermissionsPolicyBlocked(
           network::mojom::PermissionsPolicyFeature::kWriter)) {
     receivers_.ReportBadMessage("Permissions policy disabled");
@@ -1268,6 +1311,10 @@
     mojo::PendingRemote<blink::mojom::AIManagerCreateWriterClient> client,
     blink::mojom::AIWriterCreateOptionsPtr options,
     mojo::PendingRemote<on_device_model::mojom::DownloadObserver> monitor) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAIWriterAPI)) {
+    receivers_.ReportBadMessage("Feature not enabled");
+    return;
+  }
   if (IsBlocked(network::mojom::PermissionsPolicyFeature::kWriter)) {
     receivers_.ReportBadMessage("Policy or user setting disabled");
     return;
@@ -1337,6 +1384,11 @@
 void AIManager::CanCreateRewriter(
     blink::mojom::AIRewriterCreateOptionsPtr options,
     CanCreateRewriterCallback callback) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAIRewriterAPI)) {
+    std::move(callback).Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled);
+    return;
+  }
   if (IsPermissionsPolicyBlocked(
           network::mojom::PermissionsPolicyFeature::kRewriter)) {
     receivers_.ReportBadMessage("Permissions policy disabled");
@@ -1370,6 +1422,10 @@
     mojo::PendingRemote<blink::mojom::AIManagerCreateRewriterClient> client,
     blink::mojom::AIRewriterCreateOptionsPtr options,
     mojo::PendingRemote<on_device_model::mojom::DownloadObserver> monitor) {
+  if (!base::FeatureList::IsEnabled(blink::features::kAIRewriterAPI)) {
+    receivers_.ReportBadMessage("Feature not enabled");
+    return;
+  }
   if (IsBlocked(network::mojom::PermissionsPolicyFeature::kRewriter)) {
     receivers_.ReportBadMessage("Policy or user setting disabled");
     return;
@@ -1440,7 +1496,8 @@
     blink::mojom::AIClassifierCreateOptionsPtr options,
     CanCreateClassifierCallback callback) {
   if (!base::FeatureList::IsEnabled(blink::features::kAIClassifierAPI)) {
-    receivers_.ReportBadMessage("Feature not enabled");
+    std::move(callback).Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled);
     return;
   }
   // TODO(crbug.com/499365168): Enforce permissions policy and
diff --git a/chrome/browser/ai/ai_manager.h b/chrome/browser/ai/ai_manager.h
index 79b050c5..37271f01 100644
--- a/chrome/browser/ai/ai_manager.h
+++ b/chrome/browser/ai/ai_manager.h
@@ -165,6 +165,8 @@
       const base::flat_set<std::string>& default_supported);
 
  private:
+  bool IsPromptApiEnabled() const;
+
   base::OnceCallback<void(std::unique_ptr<optimization_guide::OnDeviceSession>)>
   CreateSummarizerSessionCallback(
       blink::mojom::AISummarizerCreateOptionsPtr options,
diff --git a/chrome/browser/ai/ai_language_model_unittest.cc b/chrome/browser/ai/ai_language_model_unittest.cc
index 94f36c8..02cc58d 100644
--- a/chrome/browser/ai/ai_language_model_unittest.cc
+++ b/chrome/browser/ai/ai_language_model_unittest.cc
@@ -275,7 +275,8 @@
  public:
   AILanguageModelTest() {
     scoped_feature_list_.InitWithFeaturesAndParameters(
-        {{blink::features::kAIPromptAPIMultimodalInput, {}},
+        {{blink::features::kAIPromptAPI, {}},
+         {blink::features::kAIPromptAPIMultimodalInput, {}},
          {features::kAILanguageModelOverrideConfiguration,
           {{"ai_language_model_output_buffer", "100"}}},
          {features::kAILanguageModelAppendOutputTokensToContext, {}},
diff --git a/chrome/browser/ai/ai_manager_unittest.cc b/chrome/browser/ai/ai_manager_unittest.cc
index 571e471..954ec75 100644
--- a/chrome/browser/ai/ai_manager_unittest.cc
+++ b/chrome/browser/ai/ai_manager_unittest.cc
@@ -28,6 +28,7 @@
 #include "components/policy/core/common/policy_pref_names.h"
 #include "components/prefs/pref_service.h"
 #include "content/public/browser/web_contents.h"
+#include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/mojom/base/work_in_progress.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/blink/public/common/features_generated.h"
@@ -59,8 +60,12 @@
 class AIManagerTest : public AITestUtils::AITestBase {
  public:
   AIManagerTest() {
-    scoped_feature_list_.InitAndEnableFeature(
-        blink::features::kAIClassifierAPI);
+    scoped_feature_list_.InitWithFeatures(
+        {blink::features::kAIPromptAPI, blink::features::kAIWriterAPI,
+         blink::features::kAISummarizationAPI, blink::features::kAIRewriterAPI,
+         blink::features::kAIProofreadingAPI,
+         blink::features::kAIClassifierAPI},
+        {});
   }
 
  protected:
@@ -172,6 +177,30 @@
   }
 }
 
+TEST_F(AIManagerTest, CanCreateFeatureDisabled) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitWithFeatures(
+      {}, {blink::features::kAIPromptAPI,
+           blink::features::kAIPromptAPIMultimodalInput,
+           blink::features::kAIWriterAPI, blink::features::kAISummarizationAPI,
+           blink::features::kAIRewriterAPI, blink::features::kAIProofreadingAPI,
+           blink::features::kAIClassifierAPI});
+
+  base::MockCallback<
+      base::OnceCallback<void(blink::mojom::ModelAvailabilityCheckResult)>>
+      callback;
+  EXPECT_CALL(callback, Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled))
+      .Times(6);
+
+  ai_manager_->CanCreateLanguageModel(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateWriter(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateSummarizer(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateRewriter(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateProofreader(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateClassifier(/*options=*/{}, callback.Get());
+}
+
 TEST_F(AIManagerTest, CanCreateEnterprisePolicyDisabled) {
   SetBuiltInAIAPIsEnterprisePolicy(false);
   base::MockCallback<
diff --git a/chrome/browser/ai/ai_proofreader_unittest.cc b/chrome/browser/ai/ai_proofreader_unittest.cc
index c94ce91a..816f903 100644
--- a/chrome/browser/ai/ai_proofreader_unittest.cc
+++ b/chrome/browser/ai/ai_proofreader_unittest.cc
@@ -31,6 +31,7 @@
 #include "services/on_device_model/public/cpp/features.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features_generated.h"
 #include "third_party/blink/public/mojom/ai/ai_manager.mojom.h"
 #include "third_party/blink/public/mojom/ai/model_streaming_responder.mojom.h"
 
@@ -124,6 +125,12 @@
 }
 
 class AIProofreaderTest : public AITestUtils::AITestBase {
+ public:
+  AIProofreaderTest() {
+    scoped_feature_list_.InitAndEnableFeature(
+        blink::features::kAIProofreadingAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -203,6 +210,9 @@
     auto result = proofreader_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST_F(AIProofreaderTest, CreateProofreaderNoService) {
diff --git a/chrome/browser/ai/ai_rewriter_unittest.cc b/chrome/browser/ai/ai_rewriter_unittest.cc
index 6ec1729..0c929d08 100644
--- a/chrome/browser/ai/ai_rewriter_unittest.cc
+++ b/chrome/browser/ai/ai_rewriter_unittest.cc
@@ -38,6 +38,7 @@
 #include "services/on_device_model/public/cpp/features.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features_generated.h"
 #include "third_party/blink/public/mojom/ai/ai_manager.mojom.h"
 #include "third_party/blink/public/mojom/ai/model_streaming_responder.mojom.h"
 
@@ -163,6 +164,11 @@
 }
 
 class AIRewriterTest : public AITestUtils::AITestBase {
+ public:
+  AIRewriterTest() {
+    scoped_feature_list_.InitAndEnableFeature(blink::features::kAIRewriterAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -225,6 +231,9 @@
     auto result = rewriter_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST_F(AIRewriterTest, CreateRewriterNoService) {
@@ -793,7 +802,8 @@
  public:
   AIRewriterManifestTest() {
     scoped_feature_list_.InitWithFeatures(
-        {optimization_guide::kOptimizationGuideManifestBroker,
+        {blink::features::kAIRewriterAPI,
+         optimization_guide::kOptimizationGuideManifestBroker,
          on_device_model::features::kOnDeviceModelLitertLmBackend},
         {});
   }
diff --git a/chrome/browser/ai/ai_summarizer_unittest.cc b/chrome/browser/ai/ai_summarizer_unittest.cc
index e299ffa8..44d4be61 100644
--- a/chrome/browser/ai/ai_summarizer_unittest.cc
+++ b/chrome/browser/ai/ai_summarizer_unittest.cc
@@ -134,6 +134,12 @@
 #endif  // !BUILDFLAG(IS_ANDROID)
 
 class AISummarizerTest : public AITestUtils::AITestBase {
+ public:
+  AISummarizerTest() {
+    scoped_feature_list_.InitAndEnableFeature(
+        blink::features::kAISummarizationAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -215,6 +221,9 @@
     auto result = summarizer_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST(AISummarizerStandaloneTest, CombineContexts) {
@@ -898,7 +907,8 @@
  public:
   AISummarizerManifestTest() {
     scoped_feature_list_.InitWithFeaturesAndParameters(
-        {{blink::features::kAISummarizationPerformancePreference, {}},
+        {{blink::features::kAISummarizationAPI, {}},
+         {blink::features::kAISummarizationPerformancePreference, {}},
          {optimization_guide::kOptimizationGuideManifestBroker, {}},
          {on_device_model::features::kOnDeviceModelLitertLmBackend, {}}},
         {});
diff --git a/chrome/browser/ai/ai_writer_unittest.cc b/chrome/browser/ai/ai_writer_unittest.cc
index 25a4f20..31900186 100644
--- a/chrome/browser/ai/ai_writer_unittest.cc
+++ b/chrome/browser/ai/ai_writer_unittest.cc
@@ -37,6 +37,7 @@
 #include "services/on_device_model/public/cpp/features.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features_generated.h"
 #include "third_party/blink/public/mojom/ai/ai_manager.mojom.h"
 #include "third_party/blink/public/mojom/ai/model_streaming_responder.mojom.h"
 
@@ -162,6 +163,11 @@
 }
 
 class AIWriterTest : public AITestUtils::AITestBase {
+ public:
+  AIWriterTest() {
+    scoped_feature_list_.InitAndEnableFeature(blink::features::kAIWriterAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -224,6 +230,9 @@
     auto result = writer_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST_F(AIWriterTest, CanCreateDefaultOptions) {
@@ -780,7 +789,8 @@
  protected:
   AIWriterManifestTest() {
     scoped_feature_list_.InitWithFeatures(
-        {optimization_guide::kOptimizationGuideManifestBroker,
+        {blink::features::kAIWriterAPI,
+         optimization_guide::kOptimizationGuideManifestBroker,
          on_device_model::features::kOnDeviceModelLitertLmBackend},
         {});
   }

diff --git a/chrome/browser/ai/ai_language_model_unittest.cc b/chrome/browser/ai/ai_language_model_unittest.cc
index 94f36c8..02cc58d 100644
--- a/chrome/browser/ai/ai_language_model_unittest.cc
+++ b/chrome/browser/ai/ai_language_model_unittest.cc
@@ -275,7 +275,8 @@
  public:
   AILanguageModelTest() {
     scoped_feature_list_.InitWithFeaturesAndParameters(
-        {{blink::features::kAIPromptAPIMultimodalInput, {}},
+        {{blink::features::kAIPromptAPI, {}},
+         {blink::features::kAIPromptAPIMultimodalInput, {}},
          {features::kAILanguageModelOverrideConfiguration,
           {{"ai_language_model_output_buffer", "100"}}},
          {features::kAILanguageModelAppendOutputTokensToContext, {}},
diff --git a/chrome/browser/ai/ai_manager_unittest.cc b/chrome/browser/ai/ai_manager_unittest.cc
index 571e471..954ec75 100644
--- a/chrome/browser/ai/ai_manager_unittest.cc
+++ b/chrome/browser/ai/ai_manager_unittest.cc
@@ -28,6 +28,7 @@
 #include "components/policy/core/common/policy_pref_names.h"
 #include "components/prefs/pref_service.h"
 #include "content/public/browser/web_contents.h"
+#include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/mojom/base/work_in_progress.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/blink/public/common/features_generated.h"
@@ -59,8 +60,12 @@
 class AIManagerTest : public AITestUtils::AITestBase {
  public:
   AIManagerTest() {
-    scoped_feature_list_.InitAndEnableFeature(
-        blink::features::kAIClassifierAPI);
+    scoped_feature_list_.InitWithFeatures(
+        {blink::features::kAIPromptAPI, blink::features::kAIWriterAPI,
+         blink::features::kAISummarizationAPI, blink::features::kAIRewriterAPI,
+         blink::features::kAIProofreadingAPI,
+         blink::features::kAIClassifierAPI},
+        {});
   }
 
  protected:
@@ -172,6 +177,30 @@
   }
 }
 
+TEST_F(AIManagerTest, CanCreateFeatureDisabled) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitWithFeatures(
+      {}, {blink::features::kAIPromptAPI,
+           blink::features::kAIPromptAPIMultimodalInput,
+           blink::features::kAIWriterAPI, blink::features::kAISummarizationAPI,
+           blink::features::kAIRewriterAPI, blink::features::kAIProofreadingAPI,
+           blink::features::kAIClassifierAPI});
+
+  base::MockCallback<
+      base::OnceCallback<void(blink::mojom::ModelAvailabilityCheckResult)>>
+      callback;
+  EXPECT_CALL(callback, Run(blink::mojom::ModelAvailabilityCheckResult::
+                                kUnavailableFeatureNotEnabled))
+      .Times(6);
+
+  ai_manager_->CanCreateLanguageModel(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateWriter(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateSummarizer(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateRewriter(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateProofreader(/*options=*/{}, callback.Get());
+  ai_manager_->CanCreateClassifier(/*options=*/{}, callback.Get());
+}
+
 TEST_F(AIManagerTest, CanCreateEnterprisePolicyDisabled) {
   SetBuiltInAIAPIsEnterprisePolicy(false);
   base::MockCallback<
diff --git a/chrome/browser/ai/ai_proofreader_unittest.cc b/chrome/browser/ai/ai_proofreader_unittest.cc
index c94ce91a..816f903 100644
--- a/chrome/browser/ai/ai_proofreader_unittest.cc
+++ b/chrome/browser/ai/ai_proofreader_unittest.cc
@@ -31,6 +31,7 @@
 #include "services/on_device_model/public/cpp/features.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features_generated.h"
 #include "third_party/blink/public/mojom/ai/ai_manager.mojom.h"
 #include "third_party/blink/public/mojom/ai/model_streaming_responder.mojom.h"
 
@@ -124,6 +125,12 @@
 }
 
 class AIProofreaderTest : public AITestUtils::AITestBase {
+ public:
+  AIProofreaderTest() {
+    scoped_feature_list_.InitAndEnableFeature(
+        blink::features::kAIProofreadingAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -203,6 +210,9 @@
     auto result = proofreader_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST_F(AIProofreaderTest, CreateProofreaderNoService) {
diff --git a/chrome/browser/ai/ai_rewriter_unittest.cc b/chrome/browser/ai/ai_rewriter_unittest.cc
index 6ec1729..0c929d08 100644
--- a/chrome/browser/ai/ai_rewriter_unittest.cc
+++ b/chrome/browser/ai/ai_rewriter_unittest.cc
@@ -38,6 +38,7 @@
 #include "services/on_device_model/public/cpp/features.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features_generated.h"
 #include "third_party/blink/public/mojom/ai/ai_manager.mojom.h"
 #include "third_party/blink/public/mojom/ai/model_streaming_responder.mojom.h"
 
@@ -163,6 +164,11 @@
 }
 
 class AIRewriterTest : public AITestUtils::AITestBase {
+ public:
+  AIRewriterTest() {
+    scoped_feature_list_.InitAndEnableFeature(blink::features::kAIRewriterAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -225,6 +231,9 @@
     auto result = rewriter_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST_F(AIRewriterTest, CreateRewriterNoService) {
@@ -793,7 +802,8 @@
  public:
   AIRewriterManifestTest() {
     scoped_feature_list_.InitWithFeatures(
-        {optimization_guide::kOptimizationGuideManifestBroker,
+        {blink::features::kAIRewriterAPI,
+         optimization_guide::kOptimizationGuideManifestBroker,
          on_device_model::features::kOnDeviceModelLitertLmBackend},
         {});
   }
diff --git a/chrome/browser/ai/ai_summarizer_unittest.cc b/chrome/browser/ai/ai_summarizer_unittest.cc
index e299ffa8..44d4be61 100644
--- a/chrome/browser/ai/ai_summarizer_unittest.cc
+++ b/chrome/browser/ai/ai_summarizer_unittest.cc
@@ -134,6 +134,12 @@
 #endif  // !BUILDFLAG(IS_ANDROID)
 
 class AISummarizerTest : public AITestUtils::AITestBase {
+ public:
+  AISummarizerTest() {
+    scoped_feature_list_.InitAndEnableFeature(
+        blink::features::kAISummarizationAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -215,6 +221,9 @@
     auto result = summarizer_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST(AISummarizerStandaloneTest, CombineContexts) {
@@ -898,7 +907,8 @@
  public:
   AISummarizerManifestTest() {
     scoped_feature_list_.InitWithFeaturesAndParameters(
-        {{blink::features::kAISummarizationPerformancePreference, {}},
+        {{blink::features::kAISummarizationAPI, {}},
+         {blink::features::kAISummarizationPerformancePreference, {}},
          {optimization_guide::kOptimizationGuideManifestBroker, {}},
          {on_device_model::features::kOnDeviceModelLitertLmBackend, {}}},
         {});
diff --git a/chrome/browser/ai/ai_writer_unittest.cc b/chrome/browser/ai/ai_writer_unittest.cc
index 25a4f20..31900186 100644
--- a/chrome/browser/ai/ai_writer_unittest.cc
+++ b/chrome/browser/ai/ai_writer_unittest.cc
@@ -37,6 +37,7 @@
 #include "services/on_device_model/public/cpp/features.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features_generated.h"
 #include "third_party/blink/public/mojom/ai/ai_manager.mojom.h"
 #include "third_party/blink/public/mojom/ai/model_streaming_responder.mojom.h"
 
@@ -162,6 +163,11 @@
 }
 
 class AIWriterTest : public AITestUtils::AITestBase {
+ public:
+  AIWriterTest() {
+    scoped_feature_list_.InitAndEnableFeature(blink::features::kAIWriterAPI);
+  }
+
  protected:
   optimization_guide::proto::OnDeviceModelExecutionFeatureConfig CreateConfig()
       override {
@@ -224,6 +230,9 @@
     auto result = writer_client.result().Take();
     EXPECT_OK(result);
   }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
 };
 
 TEST_F(AIWriterTest, CanCreateDefaultOptions) {
@@ -780,7 +789,8 @@
  protected:
   AIWriterManifestTest() {
     scoped_feature_list_.InitWithFeatures(
-        {optimization_guide::kOptimizationGuideManifestBroker,
+        {blink::features::kAIWriterAPI,
+         optimization_guide::kOptimizationGuideManifestBroker,
          on_device_model::features::kOnDeviceModelLitertLmBackend},
         {});
   }