diff --git a/ee/lib/gitlab/llm/chain/requests/ai_gateway.rb b/ee/lib/gitlab/llm/chain/requests/ai_gateway.rb
index 3e09041d73b2de1cf7c21873d97bd70196cf3bdd..7ad35effb180380bf43d0aadb71888d337a8f142 100644
--- a/ee/lib/gitlab/llm/chain/requests/ai_gateway.rb
+++ b/ee/lib/gitlab/llm/chain/requests/ai_gateway.rb
@@ -169,11 +169,17 @@ def request_body_chat_2(prompt:, options: {})
               additional_context: options[:additional_context]
             }.compact
 
-            {
+            response = {
               prompt: prompt,
               options: option_params,
               model_metadata: options[:model_metadata]
-            }.compact
+            }
+
+            if Feature.enabled?(:ai_merge_request_reader_for_chat, user)
+              response[:unavailable_resources] = %w[Pipelines Vulnerabilities]
+            end
+
+            response.compact
           end
 
           def payload_params(options)
diff --git a/ee/spec/lib/gitlab/llm/chain/requests/ai_gateway_spec.rb b/ee/spec/lib/gitlab/llm/chain/requests/ai_gateway_spec.rb
index 780e5e1b580cce757ec96eb7b17fdf26cbf0e575..920fb963305b4de7449bc722f5ad58bf52a10fb4 100644
--- a/ee/spec/lib/gitlab/llm/chain/requests/ai_gateway_spec.rb
+++ b/ee/spec/lib/gitlab/llm/chain/requests/ai_gateway_spec.rb
@@ -8,6 +8,10 @@
 
   subject(:instance) { described_class.new(user, tracking_context: tracking_context) }
 
+  before do
+    Feature.disable(:ai_merge_request_reader_for_chat)
+  end
+
   describe 'initializer' do
     it 'initializes the AI Gateway client' do
       expect(instance.ai_client.class).to eq(::Gitlab::Llm::AiGateway::Client)
@@ -244,6 +248,18 @@
       end
 
       it_behaves_like 'performing request to the AI Gateway'
+
+      context 'when `ai_merge_request_reader_for_chat` feature flag is enabled' do
+        before do
+          stub_feature_flags(ai_merge_request_reader_for_chat: true)
+        end
+
+        let(:body) do
+          super().merge(unavailable_resources: %w[Pipelines Vulnerabilities])
+        end
+
+        it_behaves_like 'performing request to the AI Gateway'
+      end
     end
 
     context 'when request is sent to chat tools implemented via agents' do