Check balance
GET /v1/balance returns the balance owned by the supplied API key. It accepts no user or account selector, calls no image service, and costs nothing.
Cache-Control: private, no-store, Pragma: no-cache, and Vary: Authorization, so shared caches must not retain one account’s balance.
Use available to decide whether to start a one-credit image request. Other account, rate, spend, or concurrency limits can still refuse a submit. Handle the documented error contract on every request.