sgl-project/sglang · error · ValueError

{cpath} must be an object

Error message

{cpath} must be an object

What it means

An individual entry in the conditions list is not a Mapping/object — e.g. it is a string URI or a list.

Source

Thrown at python/sglang/multimodal_gen/runtime/pipelines_core/stages/model_specific_stages/minimax_h3/request_validation.py:189

        )
    if (
        profile.max_condition_count is not None
        and len(conditions) > profile.max_condition_count
    ):
        raise ValueError(
            f"{path} allows at most {profile.max_condition_count} entries "
            f"for task {profile.task!r}, got {len(conditions)}"
        )

    aligned_frame_count = (
        minimax_h3_align_frame_count(frame_count) if frame_count is not None else None
    )
    normalized: list[dict[str, Any]] = []
    seen_frame_indices: dict[int, int] = {}
    for index, cond in enumerate(conditions):
        cpath = f"{path}[{index}]"
        if not isinstance(cond, Mapping):
            raise ValueError(f"{cpath} must be an object")
        unknown = set(cond) - _ALLOWED_CONDITION_KEYS
        if unknown:
            raise ValueError(f"{cpath} has unknown fields: {sorted(unknown)}")
        role = _require_str(cond.get("role"), f"{cpath}.role")
        if role not in (
            MINIMAX_H3_CONDITION_ROLE_KEYFRAME,
            MINIMAX_H3_CONDITION_ROLE_REFERENCE,
        ):
            raise ValueError(
                f"{cpath}.role must be keyframe or reference, " f"got {role!r}"
            )
        cond_type = _require_str(cond.get("type"), f"{cpath}.type")
        try:
            rule = profile.rule_for(role=role, condition_type=cond_type)
        except ValueError as exc:
            raise ValueError(f"{cpath}: {exc}") from exc
        uri = _require_str(cond.get("uri"), f"{cpath}.uri")

View on GitHub (pinned to 0132848349)

Solutions

1. Make every list entry an object with role/type/uri fields
2. Validate each entry with an isinstance Mapping check client-side

Example fix

// before
"conditions": ["ref.png"]
// after
"conditions": [{"role": "reference", "type": "image", "uri": "ref.png"}]

conditions = [c for c in conditions if isinstance(c, dict)]
assert len(conditions) == len(original)

def is_condition_object(v) -> bool:
    return isinstance(v, dict)

When it happens

Trigger: conditions: ["ref.png"] instead of [{"role": ..., "uri": "ref.png"}].

Common situations: Shorthand URI lists from internal tooling; mixed-format arrays after JSON round-trips.

Related errors

• {path} must be a list
• {path}.duration_seconds must be a number
• {path} must be empty for task {profile.task!r} (got {len(con
• {path} requires at least one entry for task {profile.task!r}
• {path} requires at least {profile.min_condition_count} entri

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/e9eeee50089c91e1. Report an issue: GitHub.