Capstone: a working backend

Wire the whole loop in one Backend Project, from your own code. Every item must happen after you enrolled in this track; the check measures from your enrollment date, so keys, users, and tables that existed before do not count.

1. A key: create an API key and put it in your server environment.
2. A call: use that key from your code so the gateway records it.
3. A user: sign up an end user through the auth API.
4. A table: apply a migration that changes the schema.

The natural order is the order above: the key makes the call possible, the call proves the wiring, and the signup and migration are the first real work.