fix(bedrock): inject dummy tool when tool calls present without requiring modify_params

litellm/llms/bedrock/chat/converse_transformation.py

@@ -1614,14 +1614,7 @@ class AmazonConverseConfig(BaseConfig):
         Bedrock doesn't support tool calling without `tools=` param specified.
         """
         if "tools" not in optional_params and messages is not None and has_tool_call_blocks(messages):
-            if litellm.modify_params:
-                optional_params["tools"] = add_dummy_tool(custom_llm_provider="bedrock_converse")
-            else:
-                raise litellm.UnsupportedParamsError(
-                    message="Bedrock doesn't support tool calling without `tools=` param specified. Pass `tools=` param OR set `litellm.modify_params = True` // `litellm_settings::modify_params: True` to add dummy tool to the request.",
-                    model="",
-                    llm_provider="bedrock",
-                )
+            optional_params["tools"] = add_dummy_tool(custom_llm_provider="bedrock_converse")
 
         # Drop thinking param if thinking is enabled but thinking_blocks are missing
         # This prevents the error: "Expected thinking or redacted_thinking, but found tool_use"

tests/test_litellm/llms/bedrock/chat/test_converse_transformation.py

@@ -6953,3 +6953,53 @@ def test_transform_response_honors_json_mode_kwarg_when_optional_params_lack_it(
     )
     assert result.choices[0].message.tool_calls is None
     assert json.loads(result.choices[0].message.content) == {"city": "Paris", "population": 2100000}
+
+
+def test_transform_request_injects_dummy_tool_without_tools_param():
+    """
+    Bedrock Converse rejects requests with tool turns when toolConfig is omitted.
+    LiteLLM must inject a dummy tool without requiring litellm.modify_params.
+    """
+    from litellm.llms.bedrock.chat.converse_transformation import AmazonConverseConfig
+
+    config = AmazonConverseConfig()
+    prev_modify_params = litellm.modify_params
+    litellm.modify_params = False
+    try:
+        messages = [
+            {"role": "user", "content": "Hello"},
+            {
+                "role": "assistant",
+                "content": "Calling tool",
+                "tool_calls": [
+                    {
+                        "id": "tooluse_test_dummy",
+                        "type": "function",
+                        "function": {"name": "get_x", "arguments": "{}"},
+                    }
+                ],
+            },
+            {
+                "role": "tool",
+                "tool_call_id": "tooluse_test_dummy",
+                "content": "{}",
+            },
+        ]
+        result = config.transform_request(
+            model="anthropic.claude-3-5-sonnet-20240620-v1:0",
+            messages=messages,
+            optional_params={},
+            litellm_params={},
+            headers={},
+        )
+    finally:
+        litellm.modify_params = prev_modify_params
+
+    assert "toolConfig" in result
+    tools = result["toolConfig"].get("tools", [])
+    tool_names = [
+        t.get("toolSpec", {}).get("name")
+        for t in tools
+        if isinstance(t, dict) and "toolSpec" in t
+    ]
+    assert "dummy_tool" in tool_names