microsoft/autogen · error · ValueError

model_info is required when model name is not recognized

Error message

model_info is required when model name is not recognized

What it means

Error "model_info is required when model name is not recognized" thrown in microsoft/autogen.

Source

Thrown at python/packages/autogen-ext/src/autogen_ext/models/anthropic/_anthropic_client.py:458

        completion_tokens=usage1.completion_tokens + usage2.completion_tokens,
    )


class BaseAnthropicChatCompletionClient(ChatCompletionClient):
    def __init__(
        self,
        client: Any,
        *,
        create_args: Dict[str, Any],
        model_info: Optional[ModelInfo] = None,
    ):
        self._client = client

        if model_info is None:
            try:
                self._model_info = _model_info.get_info(create_args["model"])
            except KeyError as err:
                raise ValueError("model_info is required when model name is not recognized") from err
        else:
            self._model_info = model_info

        # Validate model_info
        validate_model_info(self._model_info)

        self._create_args = create_args
        self._total_usage = RequestUsage(prompt_tokens=0, completion_tokens=0)
        self._actual_usage = RequestUsage(prompt_tokens=0, completion_tokens=0)

        # Store last used tools for anthropic API requirement
        self._last_used_tools: List[ToolParam] = []

    def _serialize_message(self, message: MessageParam) -> Dict[str, Any]:
        """Convert an Anthropic MessageParam to a JSON-serializable format."""
        if isinstance(message, dict):
            result: Dict[str, Any] = {}
            for key, value in message.items():

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Pass model_info describing capabilities for custom models

Example fix

client = AnthropicChatCompletionClient(model=..., model_info={...})

When it happens

Trigger: Thrown at python/packages/autogen-ext/src/autogen_ext/models/anthropic/_anthropic_client.py:458 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/2b7b5f33c4f133ae. Report an issue: GitHub.