chroma-core/chroma · error · ValueError

Unknown aggregate operator: {op}

Error message

Unknown aggregate operator: {op}

What it means

Error "Unknown aggregate operator: {op}" thrown in chroma-core/chroma.

Source

Thrown at chromadb/execution/expression/operator.py:1429

        if not data:
            raise ValueError("Aggregate dict cannot be empty")

        if len(data) != 1:
            raise ValueError(
                f"Aggregate dict must contain exactly one operator, got {len(data)}"
            )

        op = next(iter(data.keys()))

        if op == "$min_k":
            keys, k = _parse_k_aggregate(op, data)
            return MinK(keys=keys, k=k)
        elif op == "$max_k":
            keys, k = _parse_k_aggregate(op, data)
            return MaxK(keys=keys, k=k)
        else:
            raise ValueError(f"Unknown aggregate operator: {op}")


@dataclass
class MinK(Aggregate):
    """Keep k records with minimum aggregate key values per group"""

    keys: OneOrMany[Union[Key, str]]
    k: int

    def to_dict(self) -> Dict[str, Any]:
        return {"$min_k": {"keys": _keys_to_strings(self.keys), "k": self.k}}


@dataclass
class MaxK(Aggregate):
    """Keep k records with maximum aggregate key values per group"""

    keys: OneOrMany[Union[Key, str]]

View on GitHub (pinned to aecdd12c8a)

When it happens

Trigger: Thrown at chromadb/execution/expression/operator.py:1429 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/b283ea2c5dc1e7a0. Report an issue: GitHub.