BerriAI/litellm · error · BlackForestLabsError

Rejected polling URL: scheme must be https

Error message

Rejected polling URL: scheme must be https

What it means

Error "Rejected polling URL: scheme must be https" thrown in BerriAI/litellm.

Source

Thrown at litellm/llms/black_forest_labs/common_utils.py:42

def assert_bfl_polling_url(polling_url: str) -> None:
    """Validate that a polling URL points to a BFL-controlled host.

    BFL returns polling URLs on subdomains like ``gateway.bfl.ai`` that differ
    from the submission host ``api.bfl.ai``. A strict same-origin check would
    reject these legitimate URLs. Instead we verify the host is ``bfl.ai`` or
    any subdomain of it, which keeps the SSRF guarantee (credentials only go
    to BFL-controlled infrastructure) without false-positives on regional hosts.

    Raises:
        BlackForestLabsError: If the polling URL scheme or host is not trusted.
    """
    parsed: Final = urlparse(polling_url)
    host: Final = (parsed.hostname or "").lower()

    if parsed.scheme != "https":
        raise BlackForestLabsError(
            status_code=502,
            message="Rejected polling URL: scheme must be https",
        )

    if host != _BFL_REGISTERED_DOMAIN and not host.endswith("." + _BFL_REGISTERED_DOMAIN):
        raise BlackForestLabsError(
            status_code=502,
            message="Rejected polling URL: host is not within the bfl.ai domain",
        )


# Polling configuration
DEFAULT_POLLING_INTERVAL: Final = 1.5  # seconds
DEFAULT_MAX_POLLING_TIME: Final = 300  # 5 minutes

# Model to endpoint mapping for image edit
IMAGE_EDIT_MODELS: Final[dict[str, str]] = {
    "flux-kontext-pro": "/v1/flux-kontext-pro",

View on GitHub (pinned to 6c2dcb801b)

Solutions

1. Use an https polling URL.

When it happens

Trigger: Thrown at litellm/llms/black_forest_labs/common_utils.py:42 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/6c578e538f58973d. Report an issue: GitHub.