identify

analytics.identify({
  userId: 'user-123',
  traits: { plan: 'pro', accountState: 'active' },
  context: { source: 'auth-service' },
})

userId or anonymousId is required. Use identify after login, signup, account changes, and safe trait updates. Do not send passwords, tokens, raw profile fields, or authentication payloads.

{
  "type": "identify",
  "userId": "user-123",
  "traits": { "plan": "pro", "accountState": "active" }
}

Optional fields are context, timestamp, integrations, and messageId. The callback, when supplied as the second argument, runs after dispatch processing.