# Trace any identity

In Cross-platform identity you learned that one UID resolves to one human everywhere. The Identity Explorer lets you see it — type any handle you have, and watch the exact production resolver land it on a customer.

Source: https://cross-deck.com/university/identity-explorer/
Verified Crossdeck University lesson — prose plus real, runnable code.

## See the stitch, don't guess at it

Identity is the part of any cross-platform system that's hardest to reason about from the outside — a purchase lands on the "wrong" person, an entitlement doesn't show, and you're left wondering how the IDs actually connected. The Identity Explorer removes the guessing. You hand it any handle you have and it tells you, definitively, which customer that signal resolves to and how it got there.

## Paste any axis; watch it resolve

Open Developers → Workbench → Identity Explorer and paste any identifier you've got — a Crossdeck customer ID (cdcust_…), an anonymous handle (anon_…), your own user ID, an email, or a Stripe customer (cus_…). It round-trips that value through the resolver and shows you the canonical customer it lands on, along with the path it took to get there.

## The exact resolver — not a simulation

The crucial detail: the Explorer doesn't approximate. It calls the same production resolver that every event ingest, every webhook, and every entitlement check goes through — the one that walks the priority order you met earlier (direct customer ID → your user ID → rail key → anonymous device → fresh mint). Because it's the real thing, it does two jobs at once:

## Identity you can interrogate

Most platforms treat identity resolution as an opaque internal — you find out it went wrong when a customer emails you. Crossdeck lets you query the live resolver directly, on any handle, and see the answer the system itself would give. A "why did this land here?" mystery becomes a ten-second lookup.

email → cdcust_847
 An email round-tripped through the real resolver lands on one canonical customer — with every axis (user ID, Stripe customer, anon handle) that points at them.