BerriAI/litellm · error · UnsupportedParamsError

Google Speech-to-Text does not support response_format={resp

Error message

Google Speech-to-Text does not support response_format={response_format!r}. Supported values: {', '.join(SUPPORTED_RESPONSE_FORMATS)}. To drop unsupported openai params from the call, set `litellm.drop_params = True`

What it means

Error "Google Speech-to-Text does not support response_format={response_format!r}. Supported values: {', '.join(SUPPORTED_RESPONSE_FORMATS)}. To drop unsupported openai params from the call, set `litellm.drop_params = True`" thrown in BerriAI/litellm.

Source

Thrown at litellm/llms/vertex_ai/audio_transcription/transformation.py:63

    def map_openai_params(
        self,
        non_default_params: dict,
        optional_params: dict,
        model: str,
        drop_params: bool,
    ) -> dict:
        supported_params: Final = self.get_supported_openai_params(model)
        mapped: Final = {
            **optional_params,
            **{k: v for k, v in non_default_params.items() if k in supported_params},
        }
        response_format: Final = mapped.get("response_format")
        if response_format is None or response_format in SUPPORTED_RESPONSE_FORMATS:
            return mapped
        if drop_params or litellm.drop_params:
            return {k: v for k, v in mapped.items() if k != "response_format"}
        raise UnsupportedParamsError(
            status_code=400,
            message=(
                f"Google Speech-to-Text does not support response_format={response_format!r}. "
                f"Supported values: {', '.join(SUPPORTED_RESPONSE_FORMATS)}. "
                "To drop unsupported openai params from the call, set `litellm.drop_params = True`"
            ),
        )

    def get_error_class(self, error_message: str, status_code: int, headers: dict | Headers) -> BaseLLMException:
        return VertexAIError(status_code=status_code, message=error_message, headers=headers)

    def validate_environment(
        self,
        headers: dict,
        model: str,
        messages: list[AllMessageValues],
        optional_params: dict,
        litellm_params: dict,

View on GitHub (pinned to 77b7c6c40c)

Solutions

1. Use one of the supported response_format values listed in the error.
2. Or set litellm.drop_params = True to drop the unsupported param.

Example fix

litellm.drop_params = True

When it happens

Trigger: Triggered when an unsupported response_format is passed to Google Speech-to-Text via Vertex AI.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@77b7c6c40c (2026-08-18). Data as JSON: /api/errors/5a68843af51ea23e. Report an issue: GitHub.