From d26b776e5ec42823ee4735f7dfd0d5482b2d854f Mon Sep 17 00:00:00 2001 From: mateo-berri <277851410+mateo-berri@users.noreply.github.com> Date: Tue, 20 Oct 2026 18:36:41 -0700 Subject: [PATCH] fix(gemini): pair a tool result with its call when the client re-adds the thought signature to the call id Strands, which the AgentCore harness runs, puts provider_specific_fields.thought_signature back on the assistant tool call id as __thought__ while its tool result keeps the bare id, so the Gemini conversion found no matching call and answered 500. Ids now match with the signature suffix stripped. Also adds thought_signature_in_tool_call_id to the litellm_params inventory test and gives the pass-through tests' mocked logging objects the litellm_params a real Logging object always has. --- .../prompt_templates/factory.py | 15 ++++++- .../test_thought_signature_in_tool_call_id.py | 44 +++++++++++++++++++ ...test_gemini_passthrough_logging_handler.py | 1 + .../test_streaming_handler.py | 1 + tests/unit/types/test_litellm_params.py | 1 + 5 files changed, 61 insertions(+), 1 deletion(-) diff --git a/litellm/litellm_core_utils/prompt_templates/factory.py b/litellm/litellm_core_utils/prompt_templates/factory.py index d3197972862..ad966fde244 100644 --- a/litellm/litellm_core_utils/prompt_templates/factory.py +++ b/litellm/litellm_core_utils/prompt_templates/factory.py @@ -1261,6 +1261,13 @@ def encode_tool_call_id_with_signature(tool_call_id: str, thought_signature: str _encode_tool_call_id_with_signature = encode_tool_call_id_with_signature +def _same_tool_call(tool_call_id: str, other_tool_call_id: str) -> bool: + return ( + tool_call_id.split(THOUGHT_SIGNATURE_SEPARATOR, 1)[0] + == other_tool_call_id.split(THOUGHT_SIGNATURE_SEPARATOR, 1)[0] + ) + + def embeds_thought_signature_in_tool_call_id(litellm_params: Mapping[str, object]) -> bool: return litellm_params.get("thought_signature_in_tool_call_id") is not False @@ -1609,7 +1616,13 @@ def convert_to_gemini_tool_call_result( msg_tool_call_id: Final = message.get("tool_call_id", None) for tool in tools: prev_tool_call_id = tool.get("id", None) - if msg_tool_call_id and prev_tool_call_id and msg_tool_call_id == prev_tool_call_id: + if ( + isinstance(msg_tool_call_id, str) + and isinstance(prev_tool_call_id, str) + and msg_tool_call_id + and prev_tool_call_id + and _same_tool_call(msg_tool_call_id, prev_tool_call_id) + ): name = tool.get("function", {}).get("name", "") # Echo the OpenAI tool_call_id on functionResponse (strip thought-signature suffix). diff --git a/tests/unit/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py b/tests/unit/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py index 1146e7dac0c..2df7d0b3dd3 100644 --- a/tests/unit/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py +++ b/tests/unit/llms/vertex_ai/gemini/test_thought_signature_in_tool_call_id.py @@ -430,3 +430,47 @@ def test_bounded_tool_call_id_round_trips_to_gemini(client_keeps_provider_fields assert len(replayed_signatures) == 1 assert (replayed_signatures[0] == LONG_SIGNATURE) is client_keeps_provider_fields assert replayed_signatures[0] + + +def test_tool_result_with_bare_id_matches_call_whose_id_the_client_re_signed(): + bare_id: Final = "call_601401" + with respx.mock: + route: Final = respx.post(url__regex=GEMINI_URL_PATTERN).mock( + return_value=httpx.Response( + 200, + json={ + "candidates": [ + {"content": {"role": "model", "parts": [{"text": "Sunny"}]}, "finishReason": "STOP", "index": 0} + ], + "usageMetadata": {"promptTokenCount": 9, "candidatesTokenCount": 1, "totalTokenCount": 10}, + }, + ) + ) + litellm.completion( + model="gemini/gemini-3.5-flash", + messages=[ + USER_TURN, + { + "role": "assistant", + "content": None, + "tool_calls": [ + { + "id": encode_tool_call_id_with_signature(bare_id, LONG_SIGNATURE), + "type": "function", + "function": {"name": "get_weather", "arguments": '{"city": "Paris"}'}, + } + ], + }, + {"role": "tool", "tool_call_id": bare_id, "content": '{"temp_c": 21}'}, + ], + tools=[WEATHER_TOOL], + api_key="test-gemini-key", + thought_signature_in_tool_call_id=False, + ) + sent_body: Final = json.loads(route.calls.last.request.content) + + parts: Final = list(chain.from_iterable(turn["parts"] for turn in sent_body["contents"])) + function_calls: Final = [part for part in parts if "function_call" in part] + function_responses: Final = [part["function_response"] for part in parts if "function_response" in part] + assert [part["thoughtSignature"] for part in function_calls] == [LONG_SIGNATURE] + assert [response["name"] for response in function_responses] == ["get_weather"] diff --git a/tests/unit/proxy/pass_through_endpoints/llm_provider_handlers/test_gemini_passthrough_logging_handler.py b/tests/unit/proxy/pass_through_endpoints/llm_provider_handlers/test_gemini_passthrough_logging_handler.py index f780c056f64..31d95984996 100644 --- a/tests/unit/proxy/pass_through_endpoints/llm_provider_handlers/test_gemini_passthrough_logging_handler.py +++ b/tests/unit/proxy/pass_through_endpoints/llm_provider_handlers/test_gemini_passthrough_logging_handler.py @@ -83,6 +83,7 @@ class TestGeminiPassthroughLoggingHandler: mock_logging_obj = MagicMock(spec=LiteLLMLoggingObj) mock_logging_obj.model_call_details = {} mock_logging_obj.optional_params = {} + mock_logging_obj.litellm_params = {} mock_logging_obj.litellm_call_id = "test-call-id-123" return mock_logging_obj diff --git a/tests/unit/proxy/pass_through_endpoints/test_streaming_handler.py b/tests/unit/proxy/pass_through_endpoints/test_streaming_handler.py index da084146894..8bae17ed8b7 100644 --- a/tests/unit/proxy/pass_through_endpoints/test_streaming_handler.py +++ b/tests/unit/proxy/pass_through_endpoints/test_streaming_handler.py @@ -83,6 +83,7 @@ def _logging_obj() -> LiteLLMLoggingObj: logging_obj = MagicMock(spec=LiteLLMLoggingObj) logging_obj.model_call_details = {} logging_obj.optional_params = {} + logging_obj.litellm_params = {} logging_obj.litellm_call_id = "test-call-id" return logging_obj diff --git a/tests/unit/types/test_litellm_params.py b/tests/unit/types/test_litellm_params.py index 788d405f99f..d2aed5853ae 100644 --- a/tests/unit/types/test_litellm_params.py +++ b/tests/unit/types/test_litellm_params.py @@ -217,6 +217,7 @@ OPTION_NAMES: Final = ( "assistant_continue_message", "disable_add_transform_inline_image_block", "merge_reasoning_content_in_choices", + "thought_signature_in_tool_call_id", "enable_json_schema_validation", "complete_response", "stream_chunk_size",