roboflow/supervision · error · ValueError

Invalid VLM result type: {type(result)}. Must be {RESULT_TYP

Error message

Invalid VLM result type: {type(result)}. Must be {RESULT_TYPES[vlm]}

What it means

Error "Invalid VLM result type: {type(result)}. Must be {RESULT_TYPES[vlm]}" thrown in roboflow/supervision.

Source

Thrown at src/supervision/detection/vlm.py:195

        result: The result object to validate (type depends on VLM).
        kwargs: Dictionary of arguments to validate against required/allowed lists.

    Returns:
        The validated VLM enum value.

    Raises:
        ValueError: If the VLM, result type, or arguments are invalid.
    """
    if isinstance(vlm, str):
        try:
            vlm = VLM(vlm.lower())
        except ValueError:
            raise ValueError(
                f"Invalid vlm value: {vlm}. Must be one of {[e.value for e in VLM]}"
            )

    if not isinstance(result, RESULT_TYPES[vlm]):
        raise ValueError(
            f"Invalid VLM result type: {type(result)}. Must be {RESULT_TYPES[vlm]}"
        )

    required_args = REQUIRED_ARGUMENTS.get(vlm, [])
    for arg in required_args:
        if arg not in kwargs:
            raise ValueError(f"Missing required argument: {arg}")

    allowed_args = ALLOWED_ARGUMENTS.get(vlm, [])
    for arg in kwargs:
        if arg not in allowed_args:
            raise ValueError(f"Argument {arg} is not allowed for {vlm.name}")

    return vlm


@deprecated(  # type: ignore[untyped-decorator]
    target=_validate_vlm_parameters,

View on GitHub (pinned to 7f254d9784)

Solutions

1. Return the result from the model in the type expected for the chosen VLM (see the error message for the expected type).
2. If the model returns a different structure, extract the expected payload (string or dict) before calling the connector.

When it happens

Trigger: Thrown at src/supervision/detection/vlm.py:195 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of roboflow/supervision@7f254d9784 (2026-08-15). Data as JSON: /api/errors/93250b50a2c2873c. Report an issue: GitHub.