mem0ai/mem0 · error · ValueError

Both 'username' and 'password' must be provided together for

Error message

Both 'username' and 'password' must be provided together for authentication

What it means

Raised by the Cassandra vector store config when username and password are partially supplied. Cassandra auth in mem0 is all-or-nothing: either both credentials are set (RoleBasedAuthenticator) or both are absent (no auth). Supplying exactly one is treated as a configuration bug.

Source

Thrown at mem0/configs/vector_stores/cassandra.py:38

        None,
        description="Path to secure connect bundle for DataStax Astra DB"
    )
    protocol_version: int = Field(4, description="CQL protocol version")
    load_balancing_policy: Optional[Any] = Field(
        None,
        description="Custom load balancing policy object"
    )

    @model_validator(mode="before")
    @classmethod
    def check_auth(cls, values: Dict[str, Any]) -> Dict[str, Any]:
        """Validate authentication parameters."""
        username = values.get("username")
        password = values.get("password")

        # Both username and password must be provided together or not at all
        if (username and not password) or (password and not username):
            raise ValueError(
                "Both 'username' and 'password' must be provided together for authentication"
            )

        return values

    @model_validator(mode="before")
    @classmethod
    def check_connection_config(cls, values: Dict[str, Any]) -> Dict[str, Any]:
        """Validate connection configuration."""
        secure_connect_bundle = values.get("secure_connect_bundle")
        contact_points = values.get("contact_points")

        # Either secure_connect_bundle or contact_points must be provided
        if not secure_connect_bundle and not contact_points:
            raise ValueError(
                "Either 'contact_points' or 'secure_connect_bundle' must be provided"
            )

View on GitHub (pinned to 001c235229)

Solutions

Provide both 'username' and 'password' together in the config
If the cluster has no authentication, remove both keys entirely
Check that the environment/template supplying the credentials actually populates both values (log their presence, never their content)
Default both to None in code when either is missing so the pair stays consistent

Example fix

# before
CassandraConfig(contact_points=["h"], username="cassandra")

# after
CassandraConfig(contact_points=["h"], username="cassandra", password=os.environ["CASSANDRA_PASSWORD"])

Defensive patterns

Strategy: validation

Validate before calling

def validate_cassandra_auth(cfg: dict) -> None:
    u, p = bool(cfg.get("username")), bool(cfg.get("password"))
    if u != p:
        raise RuntimeError("Cassandra username and password must be provided together or both omitted")

Type guard

def cassandra_auth_pair_ok(cfg: dict) -> bool:
    return bool(cfg.get("username")) == bool(cfg.get("password"))

Try / catch

from pydantic import ValidationError
try:
    CassandraConfig(**cfg)
except ValidationError as e:
    if "must be provided together" in str(e):
        # either fill the missing half or drop both, then retry
        ...

Prevention

Source both credentials from one secret-fetch so they succeed or fail together
Check secret presence (not values) in logs before building config
When disabling auth, remove both keys in the same commit

When it happens

Trigger: Creating CassandraConfig with 'username' but no 'password', or 'password' but no 'username'. Falsy-vs-truthy asymmetry: one key present with a non-empty value while the other is missing/None/empty triggers it.

Common situations: Secrets loaded from different env vars where one is unset (CASSANDRA_USER set, CASSANDRA_PASSWORD missing in CI); trimming a password to empty string via a bad .strip() or templating step; switching a cluster from auth to no-auth and removing only one key.

Understand the failure class

Authentication and authorization failures — expired tokens, bad credentials, and missing scopes.

Related errors

AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15). Data as JSON: /api/errors/051986ef8add9b1e. Report an issue: GitHub.