What you need to know
Route Handlers can serve JSON for app features that belong in the same deployment. Their route should validate untrusted input and return clear status codes rather than exposing internal errors.
How to apply it
Implement the method your client needs, parse and validate request data, return a predictable response shape, and handle unexpected exceptions with safe server logs.
Common mistake to avoid
Do not assume a request body is valid because your own form created it. External clients can send missing, oversized, or malformed data.