feat: support flattened generation_kwargs with AnthropicChatGenerator

integrations/anthropic/src/haystack_integrations/components/generators/anthropic/chat/chat_generator.py

@@ -247,6 +247,8 @@ def _prepare_request_params(
         """
         # update generation kwargs by merging with the generation kwargs passed to the run method
         generation_kwargs = {**self.generation_kwargs, **(generation_kwargs or {})}
+        generation_kwargs = self._resolve_flattened_generation_kwargs(generation_kwargs)
+
         disallowed_params = set(generation_kwargs) - set(self.ALLOWED_PARAMS)
         if disallowed_params:
             logger.warning(
@@ -275,6 +277,32 @@ def _prepare_request_params(
 
         return system_messages, non_system_messages, generation_kwargs, anthropic_tools
 
+    def _resolve_flattened_generation_kwargs(self, generation_kwargs: dict[str, Any]) -> dict[str, Any]:
+        generation_kwargs = generation_kwargs.copy()
+        if "disable_parallel_tool_use" in generation_kwargs:
+            disable_parallel_tool_use = generation_kwargs.pop("disable_parallel_tool_use")
+            tool_choice = generation_kwargs.setdefault("tool_choice", {})
+            tool_choice["disable_parallel_tool_use"] = disable_parallel_tool_use
+
+        if "parallel_tool_use" in generation_kwargs:
+            parallel_tool_use = generation_kwargs.pop("parallel_tool_use")
+            disable_parallel_tool_use = not parallel_tool_use
+            tool_choice = generation_kwargs.setdefault("tool_choice", {})
+            tool_choice["disable_parallel_tool_use"] = disable_parallel_tool_use
+
+        if "tool_choice_type" in generation_kwargs:
+            tool_choice_type = generation_kwargs.pop("tool_choice_type")
+            tool_choice = generation_kwargs.setdefault("tool_choice", {})
+            tool_choice["type"] = tool_choice_type
+
+        if "thinking_budget_tokens" in generation_kwargs:
+            thinking_budget_tokens = generation_kwargs.pop("thinking_budget_tokens")
+            thinking = generation_kwargs.setdefault("thinking", {})
+            thinking["budget_tokens"] = thinking_budget_tokens
+            thinking["type"] = "enabled"
+
+        return generation_kwargs
+
     def _process_response(
         self,
         response: Message | Stream[RawMessageStreamEvent],

integrations/anthropic/tests/test_chat_generator.py

@@ -344,6 +344,27 @@ def test_run_with_params(self, chat_messages, mock_anthropic_completion):
         assert response["replies"][0].meta["model"] == "claude-sonnet-4-5"
         assert response["replies"][0].meta["finish_reason"] == "stop"
 
+    def test_run_with_flattened_generation_kwargs(self, chat_messages, mock_anthropic_completion):
+        """
+        Test that the AnthropicChatGenerator component can run with parameters.
+        """
+        component = AnthropicChatGenerator(
+            api_key=Secret.from_token("test-api-key"),
+            generation_kwargs={
+                "max_tokens": 10,
+                "thinking_budget_tokens": 1024,
+                "parallel_tool_use": False,
+                "tool_choice_type": "any",
+            },
+        )
+        component.run(chat_messages)
+
+        # Check that the component calls the Anthropic API with the correct parameters
+        _, kwargs = mock_anthropic_completion.call_args
+        assert kwargs["max_tokens"] == 10
+        assert kwargs["thinking"] == {"budget_tokens": 1024, "type": "enabled"}
+        assert kwargs["tool_choice"] == {"disable_parallel_tool_use": True, "type": "any"}
+
     def test_check_duplicate_tool_names(self, tools):
         """Test that the AnthropicChatGenerator component fails to initialize with duplicate tool names."""
         with pytest.raises(ValueError):