MemPalace/mempalace · error · UnsupportedFilterError

operator {key!r} not supported by chroma backend

Error message

operator {key!r} not supported by chroma backend

What it means

A ValueError from replica identity loading: the replica file parsed, but replica_id is not a string matching the expected id pattern. Same rationale as the corrupt-file case — minting a second id for one palace would fork op-log provenance, so the invalid file must be restored or deleted explicitly.

Source

Thrown at mempalace/backends/chroma.py:384

    raise UnsupportedFilterError(f"operator {op!r} not supported by chroma backend")


def _matches_where(meta: dict, where: Optional[dict]) -> bool:
    if not where:
        return True
    if not isinstance(where, dict):
        return False
    for key, expected in where.items():
        if key == "$and":
            if not all(_matches_where(meta, clause) for clause in expected or []):
                return False
            continue
        if key == "$or":
            if not any(_matches_where(meta, clause) for clause in expected or []):
                return False
            continue
        if key.startswith("$"):
            raise UnsupportedFilterError(f"operator {key!r} not supported by chroma backend")
        actual = meta.get(key)
        if isinstance(expected, dict):
            for op, operand in expected.items():
                if not _compare_metadata(actual, op, operand):
                    return False
        elif actual != expected:
            return False
    return True


def _metadata_cell_value(sval, ival, fval, bval):
    if sval is not None:
        return sval
    if ival is not None:
        return ival
    if fval is not None:
        return fval
    if bval is not None:

View on GitHub (pinned to 06cb6987f0)

Solutions

1. Restore the correct original replica_id string from a palace backup.
2. If the original id is lost and you accept forking provenance, delete the file and let it re-mint a valid id.
3. If scripting writes to this file, validate the value against the id pattern before writing.

import json, re
from pathlib import Path
data = json.loads((Path(palace_path)/'replica.json').read_text())
rid = data.get('replica_id')
assert isinstance(rid, str) and re.match(r'^rep_[0-9a-f]+$', rid), f'bad replica_id: {rid!r}'

def has_valid_replica_id(palace_path: str) -> bool:
    try:
        data = json.loads((Path(palace_path)/'replica.json').read_text(encoding='utf-8'))
    except Exception:
        return False
    return isinstance(data.get('replica_id'), str)

try:
    rid = load_or_mint_replica_id(palace_path)
except ValueError as e:
    if 'invalid replica_id' in str(e):
        restore_original_id_from_backup()  # or intentionally delete to re-mint

When it happens

Trigger: load_or_mint_replica_id() reads data['replica_id'] that is a non-string (int, null, list) or a string failing the _REPLICA_ID_RE format check.

Common situations: Hand-editing replica.json and storing the wrong type; a migration script writing an unquoted id; template placeholders like "REPLICA_ID" left in the file.

Related errors

• operator {op!r} not supported by chroma backend
• --metadata is not valid JSON: {exc}
• --metadata must be a JSON object
• invalid repair backup record at line {line_number}
• metadata is not JSON-serializable: {exc}

AI-assisted analysis of MemPalace/mempalace@06cb6987f0 (2026-08-15). Data as JSON: /api/errors/a2ac9b3a1eae4099. Report an issue: GitHub.