What does the hosted gateway take care of?

The gateway sends a request to a supported provider. A fallback can try another available route if the first one does not respond in time. Decide which routes are acceptable for the work before using fallback. Your app still needs a clear response when none are available.

What changes when you buy credits or bring your own provider account?

The current free tier covers a subset of models and has lower model limits. Purchasing credits moves the team to paid and replaces the monthly free credit. Using your own provider key requires the paid tier and purchased gateway credits. For calls made with that key, the provider bills you directly. If the gateway retries with its own credentials, the fallback can use your gateway credits. Check add-on charges separately.

Which settings decide where the request can go?

Vercel documents team-wide retention controls and request-specific controls for retention and training. A zero data retention rule can narrow the set of eligible providers. Vercel lists request-level and team-wide zero retention for Pro, Enterprise or teams with purchased credits. A Pro trial needs purchased credits, and team-wide zero retention has a separate request charge. Check the enabled policy, enabled routes and separate app logging before sending anything private. Keep the routing rules and budget notes alongside your tests.

What should an app do if both approved routes are unavailable?

Sketch a demo menu-writing app. Its first approved route times out and its second approved route is unavailable. Use fictional data and a paper route table.

Record what each route may handle
Give both routes the same allowed demo data and note which account would pay for each.
Choose what the reader sees
Write a clear try-again message when the routes are unavailable. Leave the app’s previous saved draft intact.