BerriAI/litellm · error · NotImplementedError

Vertex AI models are not supported yet

Error message

Vertex AI models are not supported yet

What it means

Sentinel NotImplementedError in the Vertex AI base config's validate_environment: this generic provider path does not implement header validation (auth is handled per-mode), so any call reaching it is unsupported.

Source

Thrown at litellm/llms/vertex_ai/common_utils.py:1069

        Factory method to create a token counter for this provider.

        Returns:
            Optional TokenCounterInterface implementation for this provider,
            or None if token counting is not supported.
        """
        return VertexAITokenCounter()

    def validate_environment(
        self,
        headers: dict,
        model: str,
        messages: list[AllMessageValues],
        optional_params: dict,
        litellm_params: dict,
        api_key: str | None = None,
        api_base: str | None = None,
    ) -> dict:
        raise NotImplementedError("Vertex AI models are not supported yet")

    def get_models(self, api_key: str | None = None, api_base: str | None = None) -> list[str]:
        """
        Returns a list of models supported by this provider.
        """
        raise NotImplementedError("Vertex AI models are not supported yet")

    @staticmethod
    def get_api_key(api_key: str | None = None) -> str | None:
        raise NotImplementedError("Vertex AI models are not supported yet")

    @staticmethod
    def get_api_base(
        api_base: str | None = None,
    ) -> str | None:
        raise NotImplementedError("Vertex AI models are not supported yet")

    @staticmethod

View on GitHub (pinned to 77b7c6c40c)

Solutions

1. This route does not yet support Vertex AI models; use the supported vertex_ai/ call path.
2. Track support via litellm releases/issues.

Example fix

# use the documented vertex_ai provider route for this call type.

When it happens

Trigger: Triggered when calling a code path where Vertex AI models are not yet supported.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@77b7c6c40c (2026-08-18). Data as JSON: /api/errors/ba781a7eeb44214f. Report an issue: GitHub.