chroma-core/chroma · error · InvalidHashError

Invalid hash algorithm specified: {alg}

Error message

Invalid hash algorithm specified: {alg}

What it means

Raised by _read_migration_file when the hash_alg argument is neither 'md5' nor 'sha256' (chromadb/db/migrations.py:267) — InvalidHashError. It guards the config value that decides how migration SQL is hashed for consistency checks, and fires before any SQL is read or applied.

Source

Thrown at chromadb/db/migrations.py:267

def _read_migration_file(file: MigrationFile, hash_alg: str) -> Migration:
    """Read a migration file"""
    if "path" not in file or not file["path"].is_file():
        raise FileNotFoundError(
            f"No migration file found for dir {file['dir']} with filename {file['filename']} and scope {file['scope']} at version {file['version']}"
        )
    sql = file["path"].read_text()

    if hash_alg == "md5":
        hash = (
            hashlib.md5(sql.encode("utf-8"), usedforsecurity=False).hexdigest()
            if sys.version_info >= (3, 9)
            else hashlib.md5(sql.encode("utf-8")).hexdigest()
        )
    elif hash_alg == "sha256":
        hash = hashlib.sha256(sql.encode("utf-8")).hexdigest()
    else:
        raise InvalidHashError(alg=hash_alg)

    return {
        "hash": hash,
        "sql": sql,
        "dir": file["dir"],
        "filename": file["filename"],
        "version": file["version"],
        "scope": file["scope"],
    }

View on GitHub (pinned to aecdd12c8a)

Solutions

1. Set the value to exactly 'md5' or 'sha256' (lowercase, no separators).
2. If you wrote the config plumbing yourself, validate the setting at startup against the allowed set rather than letting it fail deep in migration loading.
3. Upgrade Chroma if you expect a newer algorithm to be supported.

Example fix

# before
find_migrations(dir, scope, hash_alg="sha-256")  # InvalidHashError

# after
find_migrations(dir, scope, hash_alg="sha256")

assert hash_alg in ("md5", "sha256"), f"Unsupported hash_alg: {hash_alg}"

from chromadb.db.migrations import InvalidHashError
try:
    find_migrations(dir, scope, hash_alg=alg)
except InvalidHashError:
    alg = "md5"
    find_migrations(dir, scope, hash_alg=alg)

When it happens

Trigger: Passing a migrations hash-algorithm setting/parameter with an unsupported value (anything other than the exact strings 'md5' or 'sha256', including case variants like 'MD5' or 'SHA-256'). This is plumbed through migration configuration internals, not the public client API.

Common situations: Custom deployments or forks that expose hash algorithm config and set it to 'sha512'/'sha-256'/uppercase variants; copy-pasted config snippets; code written against a newer/older Chroma that accepted different algorithm names.

Related errors

• Inconsistent hashes in {path}:db hash was {db_hash}, source
• No migration file found for dir {file['dir']} with filename
• The model name is required.
• Failed to fetch ${input} with status ${resp.status}: ${resp.
• The model name cannot be changed after initialization.

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/5b6e11f956bef9fd. Report an issue: GitHub.