User Identification

Associate the current browser with a known user (similar to PostHog’s identify). Call once after login or signup; every later push() automatically includes the person context.

Prefer usertrax.identify() as the single call site: when the feedback widget is also on the page, the same call identifies the visitor there too (hides the email field, attaches user metadata). Identity is persisted in localStorage (usertrax_identify), so the widget picks it up even if it loads after the tracker.

// After the user signs in
usertrax.identify("user_xyz", {
  email: "jane@example.com",
  plan: "team",
  seats: 5,
});

// Later conversions inherit user_data + meta snapshot
usertrax.push({ event: "purchase", total: 49.99, currency: "EUR" });

tracker.identify("user_xyz", {
  email: "jane@example.com",
  plan: "team",
});

1. Persistence — Stored in localStorage (usertrax_identify) and reused across page loads and sessions.
2. user_data merge — Canonical trait keys (email, phone, phone_number, first_name, last_name, name, customer_id, address) are merged into each conversion’s user_data. The distinct id becomes customer_id when you do not set one explicitly. Fields on a single push({ user_data: … }) override traits from identify.
3. Full trait snapshot — All traits (including custom keys like plan or seats) are sent on every conversion under meta_data.$usertrax_identify:

{
  "distinct_id": "user_xyz",
  "traits": { "email": "jane@example.com", "plan": "team", "seats": 5 }
}

4. PostHog — When PostHog is loaded and usertraxConfig.posthog is not false, identify also calls posthog.identify(distinctId, traits).
5. Feedback widget — Dispatches usertrax:identify so a loaded feedback widget applies the same identity (also hydrates from localStorage on boot).

Use setUserData() when you only need Google Enhanced Conversions hashing without a stable distinct id — see Ads & Enhanced Conversions. Use identify() when you want a persistent person id and traits on all events.