Add anthropic 'none' tool choice param support (#11695)

* docs(index.md): add stable pip package

* fix(anthropic/chat/transformation.py): add 'none' tool choice mapping

Allows disabling anthropic tool calling

Maintain parity

* fix(transformation.py): if tool_choice="none" ignore 'disable_parallel_Tool_use'

unsupported param from anthropic - makes sense as the 'none' implies no tool calls are being made

litellm/llms/anthropic/chat/transformation.py

@@ -157,6 +157,8 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
             )
         elif tool_choice == "required":
             _tool_choice = AnthropicMessagesToolChoice(type="any")
+        elif tool_choice == "none":
+            _tool_choice = AnthropicMessagesToolChoice(type="none")
         elif isinstance(tool_choice, dict):
             _tool_name = tool_choice.get("function", {}).get("name")
             _tool_choice = AnthropicMessagesToolChoice(type="tool")
@@ -166,7 +168,9 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
         if parallel_tool_use is not None:
             # Anthropic uses 'disable_parallel_tool_use' flag to determine if parallel tool use is allowed
             # this is the inverse of the openai flag.
-            if _tool_choice is not None:
+            if tool_choice == "none":
+                pass
+            elif _tool_choice is not None:
                 _tool_choice["disable_parallel_tool_use"] = not parallel_tool_use
             else:  # use anthropic defaults and make sure to send the disable_parallel_tool_use flag
                 _tool_choice = AnthropicMessagesToolChoice(

litellm/types/llms/anthropic.py

@@ -7,7 +7,7 @@ from .openai import ChatCompletionCachedContent, ChatCompletionThinkingBlock
 
 
 class AnthropicMessagesToolChoice(TypedDict, total=False):
-    type: Required[Literal["auto", "any", "tool"]]
+    type: Required[Literal["auto", "any", "tool", "none"]]
     name: str
     disable_parallel_tool_use: bool  # default is false
 

tests/test_litellm/llms/anthropic/chat/test_anthropic_chat_transformation.py

@@ -209,6 +209,15 @@ def test_add_code_execution_tool():
     assert tools[0]["type"] == "code_execution_20250522"
 
 
+def test_map_tool_choice():
+    config = AnthropicConfig()
+
+    tool_choice = "none"
+    result = config._map_tool_choice(tool_choice=tool_choice, parallel_tool_use=True)
+    assert result is not None
+    assert result["type"] == "none"
+    print(result)
+
 def test_transform_response_with_prefix_prompt():
     import httpx
 
@@ -252,3 +261,4 @@ def test_transform_response_with_prefix_prompt():
         result.choices[0].message.content
         == "You are a helpful assistant. The grass is green."
     )
+