mem0ai/mem0 · critical · Error

PGVector requires either connectionString or ${missingFields

Error message

PGVector requires either connectionString or ${missingFields.join(", ")}

What it means

PgVector accepts either a connectionString or discrete connection fields. If no usable connection string is found and any of user, password, host, port is missing/empty, the constructor throws this error listing the missing fields. It fails fast before any network call is attempted.

Source

Thrown at mem0-ts/src/oss/src/vector_stores/pgvector.ts:186

  hnsw?: boolean;
}

function getConnectionString(config: PGVectorConfig): string | undefined {
  return config.connectionString?.trim() || undefined;
}

function validateConnectionConfig(config: PGVectorConfig): void {
  if (getConnectionString(config)) {
    return;
  }

  const missingFields = ["user", "password", "host", "port"].filter((field) => {
    const v = config[field as keyof PGVectorConfig];
    return v === undefined || v === null || v === "";
  });

  if (missingFields.length > 0) {
    throw new Error(
      `PGVector requires either connectionString or ${missingFields.join(", ")}`,
    );
  }
}

function buildClientConfig(
  config: PGVectorConfig,
  database?: string,
): ClientConfig {
  const connectionString = getConnectionString(config);
  if (connectionString) {
    return {
      connectionString,
      ...(config.ssl !== undefined ? { ssl: config.ssl } : {}),
    };
  }

  return {

View on GitHub (pinned to 001c235229)

Solutions

Provide a full connection string: new PgVector({ connectionInfo: 'postgres://user:pass@host:5432/db', ... })
Or supply all discrete fields: user, password, host, port (and optionally database)
Check that the env vars feeding the config are actually set in the runtime environment (docker-compose env, k8s secrets, dotenv loaded)
Verify none of the values are empty strings — empty counts as missing

Example fix

// before
const vs = new PgVector({ host: 'db', port: 5432, database: 'mem0' });

// after
const vs = new PgVector({
  user: 'mem0',
  password: process.env.PGPASSWORD,
  host: 'db',
  port: 5432,
  database: 'mem0',
});

Defensive patterns

Strategy: validation

Validate before calling

function validatePgConfig(c: any): void {
  const cs = c?.connectionString ?? c?.connectionInfo;
  if (cs && String(cs).trim() !== '') return;
  const missing = ['user','password','host','port'].filter(f => !c?.[f]);
  if (missing.length) throw new Error(`PG config missing: ${missing.join(', ')}`);
}
validatePgConfig(pgConfig);

Type guard

const hasPgCredentials = (c: any): boolean =>
  !!(c?.connectionString ?? c?.connectionInfo) ||
  ['user','password','host','port'].every(f => !!c?.[f]);

Try / catch

try { const vs = new PgVector(pgConfig); } catch (e) { if (e instanceof Error && e.message.includes('PGVector requires')) { /* fail deployment config check, do not retry */ } throw e; }

Prevention

Prefer a single CONNECTION STRING env var over four discrete ones
Fail fast at app boot: assert required env vars exist before constructing stores
Include PG config in a smoke test that constructs the store in CI

When it happens

Trigger: Constructing PgVector with only { host, port, database } (no user/password and no connectionString), passing an empty-string connectionString, or reading config from env vars that are undefined (e.g. process.env.PGHOST set but PGUSER/PGPASSWORD unset when building the discrete config).

Common situations: Switching from a connection URL to individual env vars in Docker/Kubernetes and forgetting one; a .env file not loaded so PG* vars are undefined; trailing whitespace or empty strings in config; deploying with a partially templated secret.

Related errors

AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15). Data as JSON: /api/errors/6d5028eee6fbbec6. Report an issue: GitHub.