mem0ai/mem0 · critical · ImportError

Apache Cassandra vector store requires cassandra-driver. Ple

Error message

Apache Cassandra vector store requires cassandra-driver. Please install it using 'pip install cassandra-driver'

What it means

Module-level ImportError raised when 'cassandra-driver' is not installed. CassandraDB imports cassandra.auth.PlainTextAuthProvider and cassandra.cluster.Cluster at the top of mem0/vector_stores/cassandra.py; failure aborts the import of the whole module, so the class cannot even be referenced.

Source

Thrown at mem0/vector_stores/cassandra.py:14

import json
import logging
import re
import uuid
from typing import Any, Dict, List, Optional

import numpy as np
from pydantic import BaseModel

try:
    from cassandra.auth import PlainTextAuthProvider
    from cassandra.cluster import Cluster
except ImportError:
    raise ImportError(
        "Apache Cassandra vector store requires cassandra-driver. "
        "Please install it using 'pip install cassandra-driver'"
    )

from mem0.vector_stores.base import VectorStoreBase

logger = logging.getLogger(__name__)

_SAFE_IDENTIFIER_RE = re.compile(r'^[a-zA-Z_][a-zA-Z0-9_]{0,127}$')


def _validate_identifier(name: str, label: str = "identifier") -> str:
    if not _SAFE_IDENTIFIER_RE.match(name):
        raise ValueError(
            f"Invalid {label} '{name}': only letters, digits, and underscores are allowed, "
            "must start with a letter or underscore, and be at most 128 characters."
        )
    return name

View on GitHub (pinned to 001c235229)

Solutions

1. Install the driver: pip install cassandra-driver.
2. Remove the Cassandra import/config if the backend is not actually used.
3. Guard provider selection so the module is only imported when the driver is present.

Example fix

# before
from mem0.vector_stores.cassandra import CassandraDB  # ImportError

# after
# pip install cassandra-driver
from mem0.vector_stores.cassandra import CassandraDB

try:
    import cassandra  # noqa: F401
    CASSANDRA_OK = True
except ImportError:
    CASSANDRA_OK = False

if provider == "cassandra" and not CASSANDRA_OK:
    raise SystemExit("cassandra-driver missing: pip install cassandra-driver")

When it happens

Trigger: Any import of mem0.vector_stores.cassandra or VectorStoreConfig(provider='cassandra') without cassandra-driver installed. Fires at import time, before any connection to the cluster is attempted.

Common situations: Choosing the Cassandra backend without adding the driver to the environment; CI smoke tests that iterate over all vector store modules; slim Docker images built from mem0ai core without extras.

Related errors

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AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15). Data as JSON: /api/errors/5fb6909812464e6e. Report an issue: GitHub.