What changed
No action needed unless you validate responses against a closed schema.
Affects GET /v13/deployments/{idOrUrl}.
Who is affected
Code that reads GET /v13/deployments/{idOrUrl} (routes[].transforms[].fallback).
Before and after
| Where | Before | After |
|---|---|---|
| GET /v13/deployments/{idOrUrl} · routes[].transforms[].fallback | absent | present |
| PATCH /v12/deployments/{id}/cancel · routes[].transforms[].fallback | absent | present |
| POST /v13/deployments · routes[].transforms[].fallback | absent | present |
Based on Vercel’s published API specification. How severity is decided.