Vercel CLI 62.5.0 @vercel/backends 16.0.0

The generated artifact is:

functions/index.func

with:

handler: server.mjs launcherType: Nodejs runtime: nodejs22.x architecture: x86_64

The exact generated artifact was hydrated and executed locally.

Local results:

GET / -> 200 GET /healthz -> 200 GET /favicon.ico -> 404 GET /favicon.png -> 404 GET /api/session without authentication -> 401

The process remains alive and does not crash.

Node.js 22 works locally. Node.js 24 also works locally.

The application is a plain Node.js HTTP server using server.listen(PORT, HOST).

There is no top-level await, no module-scope network request, no module-scope Supabase request, and no process.exit().

The important symptom is that Vercel successfully creates a real Function Invocation on Node.js 22.x with Start Type "Hot", but the invocation makes no outgoing API requests, does not return an HTTP response, and terminates after approximately 60 seconds with INTERNAL_FUNCTION_INVOCATION_FAILED.

Could someone please help determine whether this is related to:

1. Node.js HTTP server listener capture/attachment
2. Vercel's generated server.mjs handler
3. Fluid Compute request forwarding
4. an internal runtime/bootstrap timeout
5. an internal Function termination condition
6. a Vercel platform issue with generic Node.js servers

I have already verified the application and generated Vercel artifact independently outside the Vercel cloud runtime.

I am not looking for a speculative application rewrite. I would like to understand what is happening inside the Vercel Function invocation.

Deployment ID: dpl_2GfrRufjiuaNFRDwgsm7wuwy6Puv

Invocation ID: 01M49K68WC1446HVJBTS37K...

Thank you.