Clerk + TrackStack: identity for B2B conversion match rates

Ad platforms match on hashed email, phone, and external ID. If you only send anonymous PageView events until checkout, mid-funnel optimization never sees a stable key.

Clerk exposes email and user.id as soon as the session is active — that is the right moment for identify() and SignUp.

After Clerk loads the session, call identify with the Clerk user ID as external ID and email from session.user.primaryEmailAddress. Then capture SignUp on first session creation — not on every page load.

Use a ref or server flag to fire signup once per user.

const { user } = useUser();

useEffect(() => {
  if (!user?.id || !user.primaryEmailAddress?.emailAddress) return;

  trackstack.identify(user.id, {
    email: user.primaryEmailAddress.emailAddress,
  });

  trackstack.capture("SignUp", {
    email: user.primaryEmailAddress.emailAddress,
    eventId: `signup_${user.id}`,
  });
}, [user?.id]);

Clerk webhooks (user.created) are ideal for server-authoritative SignUp when you want to avoid duplicate client fires. Verify webhook signatures and capture with the same eventId scheme.

See SSO integration for dashboard checklist items.

For Clerk Organizations, pass orgId as a custom property on trial and purchase events. Sales-assisted accounts often convert under org billing emails — still hash the work email that ads matched.

TrackStack dashboard uses Clerk for team access — separate from your app's capture keys. Keep production capture keys scoped with domain allowlisting.