Vercel: defaultFor can now return "nextjs-tracing"

What changed

Producer-side tools call this additive. It breaks exhaustive switches, strict parsers and generated client enums.

Affects source.defaultFor on POST /v1/drains.

New value: nextjs-tracing.

can now return "nextjs-tracing"

Who is affected

Code that reads POST /v1/drains (source.defaultFor).

Before and after

Where	Before	After
POST /v1/drains · source.defaultFor	"eve-tracing"	"eve-tracing", "nextjs-tracing"
GET /v1/drains/{id} · source.defaultFor	"eve-tracing"	"eve-tracing", "nextjs-tracing"
PATCH /v1/drains/{id} · source.defaultFor	"eve-tracing"	"eve-tracing", "nextjs-tracing"
GET /v2/integrations/log-drains · source.defaultFor	"eve-tracing"	"eve-tracing", "nextjs-tracing"
POST /v2/integrations/log-drains · source.defaultFor	"eve-tracing"	"eve-tracing", "nextjs-tracing"

Code that breaks

switch (response.source.defaultFor) {
  // existing branches …
  // no branch for "nextjs-tracing"
  default:
    throw new Error("unexpected defaultFor");
}

Based on Vercel’s published API specification. How severity is decided.