langchain-ai/langgraph · error · ValueError

Unsupported match type

Error message

Unsupported match type: {match_type}

What it means

Dispatch guard in the in-memory store's namespace matching helper (used by list_namespaces): a MatchCondition was encountered whose match_type is neither 'prefix' nor 'suffix'. The function walks key-vs-path element pairs honoring '*' wildcards for those two modes; any other tag (typo like 'exact', None, or a new mode) falls through to this raise.

Solutions

1. Construct MatchCondition(match_type='prefix'|'suffix', path=...) when calling list_namespaces programmatically
2. Use the supported kwargs (prefix=..., suffix=...) of list_namespaces instead of hand-built conditions
3. Check for typos or stale enum values if building conditions dynamically

When it happens

Trigger: Thrown at libs/checkpoint/langgraph/store/memory/__init__.py:548 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of langchain-ai/langgraph@38031739e5 (2026-08-26). Data as JSON: /api/errors/1af748b514ff08aa. Report an issue: GitHub.

Appendix: source

Thrown at libs/checkpoint/langgraph/store/memory/__init__.py:548

    if len(key) < len(path):
        return False

    if match_type == "prefix":
        for k_elem, p_elem in zip(key, path, strict=False):
            if p_elem == "*":
                continue  # Wildcard matches any element
            if k_elem != p_elem:
                return False
        return True
    elif match_type == "suffix":
        for k_elem, p_elem in zip(reversed(key), reversed(path), strict=False):
            if p_elem == "*":
                continue  # Wildcard matches any element
            if k_elem != p_elem:
                return False
        return True
    else:
        raise ValueError(f"Unsupported match type: {match_type}")


def _compare_values(item_value: Any, filter_value: Any) -> bool:
    """Compare values in a JSONB-like way, handling nested objects."""
    if isinstance(filter_value, dict):
        if any(k.startswith("$") for k in filter_value):
            return all(
                _apply_operator(item_value, op_key, op_value)
                for op_key, op_value in filter_value.items()
            )
        if not isinstance(item_value, dict):
            return False
        return all(
            _compare_values(item_value.get(k), v) for k, v in filter_value.items()
        )
    elif isinstance(filter_value, (list, tuple)):
        return (
            isinstance(item_value, (list, tuple))

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