BerriAI/litellm · error · ValueError

Parameter {key} is not supported for model {model}. Supporte

Error message

Parameter {key} is not supported for model {model}. Supported parameters are {supported_params}. Set drop_params=True to drop unsupported parameters.

What it means

Error "Parameter {key} is not supported for model {model}. Supported parameters are {supported_params}. Set drop_params=True to drop unsupported parameters." thrown in BerriAI/litellm.

Source

Thrown at litellm/llms/fal_ai/image_generation/nano_banana_transformation.py:68

    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)
        for key, value in non_default_params.items():
            if key == "response_format":
                continue
            elif key == "n":
                if "num_images" not in optional_params:
                    optional_params["num_images"] = value
            elif key == "size":
                if "aspect_ratio" not in optional_params:
                    optional_params["aspect_ratio"] = self._map_aspect_ratio(value)
            elif key not in optional_params and not drop_params:
                raise ValueError(
                    f"Parameter {key} is not supported for model {model}. "
                    f"Supported parameters are {supported_params}. "
                    "Set drop_params=True to drop unsupported parameters."
                )
        return optional_params

    def _map_aspect_ratio(self, size: str) -> str:
        if not isinstance(size, str) or "x" not in size:
            return "1:1"
        try:
            width, height = (int(part) for part in size.split("x"))
            target: Final = width / height
        except (ValueError, ZeroDivisionError):
            return "1:1"

        def ratio_of(aspect_ratio: str) -> float:
            w, h = (int(part) for part in aspect_ratio.split(":"))
            return w / h

View on GitHub (pinned to 6c2dcb801b)

Solutions

1. Remove the unsupported parameter or set drop_params=True.

When it happens

Trigger: Thrown at litellm/llms/fal_ai/image_generation/nano_banana_transformation.py:68 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@6c2dcb801b (2026-08-15). Data as JSON: /api/errors/464cd516d50f8294. Report an issue: GitHub.