fix(drivers-prompt-anthropic): make top_p and top_k optional to avoid API conflict (#2070)

* fix(drivers-prompt-anthropic): make top_p and top_k optional to avoid API conflict

Newer Anthropic models (Claude 4.6+) reject requests that specify both
`temperature` and `top_p`. Change `top_p` and `top_k` to Optional fields
defaulting to None, and only include them in the API params when
explicitly set. This follows Anthropic's recommendation to use
`temperature` alone for most use cases.

Made-with: Cursor

* fix: exclude temperature from API params when top_p is explicitly set

When top_p is provided, temperature is now omitted from the Anthropic
API request to avoid the mutual exclusivity conflict on newer models.
This ensures callers who prefer top_p-based sampling don't hit a 400.

Made-with: Cursor

Author: ian-griptape-ai

griptape/drivers/prompt/anthropic_prompt_driver.py

@@ -65,8 +65,8 @@ class AnthropicPromptDriver(BasePromptDriver):
         default=Factory(lambda self: AnthropicTokenizer(model=self.model), takes_self=True),
         kw_only=True,
     )
-    top_p: float = field(default=0.999, kw_only=True, metadata={"serializable": True})
-    top_k: int = field(default=250, kw_only=True, metadata={"serializable": True})
+    top_p: Optional[float] = field(default=None, kw_only=True, metadata={"serializable": True})
+    top_k: Optional[int] = field(default=None, kw_only=True, metadata={"serializable": True})
     tool_choice: dict = field(default=Factory(lambda: {"type": "auto"}), kw_only=True, metadata={"serializable": False})
     use_native_tools: bool = field(default=True, kw_only=True, metadata={"serializable": True})
     structured_output_strategy: StructuredOutputStrategy = field(
@@ -123,12 +123,11 @@ def _base_params(self, prompt_stack: PromptStack) -> dict:
 
         params = {
             "model": self.model,
-            "temperature": self.temperature,
             "stop_sequences": self.tokenizer.stop_sequences,
-            "top_p": self.top_p,
-            "top_k": self.top_k,
             "max_tokens": self.max_tokens,
             "messages": messages,
+            **({"top_p": self.top_p} if self.top_p is not None else {"temperature": self.temperature}),
+            **({"top_k": self.top_k} if self.top_k is not None else {}),
             **({"system": system_message} if system_message else {}),
             **self.extra_params,
         }

tests/unit/configs/drivers/test_anthropic_drivers_config.py

@@ -22,8 +22,8 @@ def test_to_dict(self, config):
                 "max_tokens": 1000,
                 "stream": False,
                 "model": "claude-3-7-sonnet-latest",
-                "top_p": 0.999,
-                "top_k": 250,
+                "top_p": None,
+                "top_k": None,
                 "use_native_tools": True,
                 "structured_output_strategy": "tool",
                 "extra_params": {},

tests/unit/drivers/prompt/test_anthropic_prompt_driver.py

@@ -382,8 +382,6 @@ def test_try_run(self, mock_client, prompt_stack, messages, use_native_tools, st
             model=driver.model,
             max_tokens=1000,
             temperature=0.1,
-            top_p=0.999,
-            top_k=250,
             **{"system": "system-input"} if prompt_stack.system_messages else {},
             **{
                 "tools": self.ANTHROPIC_TOOLS if use_native_tools else {},
@@ -430,8 +428,6 @@ def test_try_stream_run(
             max_tokens=1000,
             temperature=0.1,
             stream=True,
-            top_p=0.999,
-            top_k=250,
             **{"system": "system-input"} if prompt_stack.system_messages else {},
             **{
                 "tools": self.ANTHROPIC_TOOLS if use_native_tools else {},
@@ -464,6 +460,40 @@ def test_try_stream_run(
         event = next(stream)
         assert event.usage.output_tokens == 10
 
+    def test_try_run_with_top_p_and_top_k(self, mock_client, prompt_stack, messages):
+        # Given
+        driver = AnthropicPromptDriver(
+            model="claude-3-haiku",
+            api_key="api-key",
+            top_p=0.9,
+            top_k=100,
+        )
+
+        # When
+        driver.try_run(prompt_stack)
+
+        # Then
+        call_kwargs = mock_client.return_value.messages.create.call_args
+        assert call_kwargs.kwargs["top_p"] == 0.9
+        assert call_kwargs.kwargs["top_k"] == 100
+        assert "temperature" not in call_kwargs.kwargs
+
+    def test_try_run_without_top_p_and_top_k(self, mock_client, prompt_stack, messages):
+        # Given
+        driver = AnthropicPromptDriver(
+            model="claude-3-haiku",
+            api_key="api-key",
+        )
+
+        # When
+        driver.try_run(prompt_stack)
+
+        # Then
+        call_kwargs = mock_client.return_value.messages.create.call_args
+        assert "top_p" not in call_kwargs.kwargs
+        assert "top_k" not in call_kwargs.kwargs
+        assert call_kwargs.kwargs["temperature"] == 0.1
+
     def test_verify_structured_output_strategy(self):
         assert AnthropicPromptDriver(model="foo", structured_output_strategy="tool")