What changed
No action needed unless you validate responses against a closed schema.
Affects POST /v1/projects/{projectId}/routes.
Who is affected
Code that reads POST /v1/projects/{projectId}/routes (route.route.transforms[].fallback).
Before and after
| Where | Before | After |
|---|---|---|
| POST /v1/projects/{projectId}/routes · route.route.transforms[].fallback | absent | present |
| PATCH /v1/projects/{projectId}/routes/{routeId} · route.route.transforms[].fallback | absent | present |
Based on Vercel’s published API specification. How severity is decided.