Deployment Issue: Vike SSR on Vercel — Hydration Chunks Timing Out

[KabDIY]

ENVIRONMENT:
React 19
Node 20.19.5
Vike 0.4.240
Vite 7.1.7
Vike-React 0.6.6
Vite/plugin-react 5.0.3

TARGET: VERCEL (EDGE FUNCTIONS)
Summary: We’ve been deploying a Vike SSR app to Vercel, and while SSR routes and API endpoints work fine, client-side hydration chunks consistently fail with 504 timeouts. The logs show Vercel trying to serve /assets/client..js and /assets/entries/.js through the function runtime instead of static delivery.

WHAT WE'VE TRIED:
Generated a fallback manifest.json from Vike’s internal .vite/ structure
Patched .vercel/output/static/assets/ with all client chunks
Wired SSR entry (server/entry.js) to .vercel/output/functions/render.func/index.mjs
Configured vercel.json with rewrites and headers to preserve static routing
Reverted to earlier vercel.json where logs were visible (before 404s replaced 504s)

CURRENT STATUS:
SSR works, API works, logs show successful data fetches
Hydration chunks still ghosted or misrouted
Static assets either 504 or 404 depending on rewrite config
Manifest is present, but Vercel doesn’t preload chunks

REQUEST:
Looking for guidance from anyone who’s successfully deployed Vike SSR to Vercel — especially around manifest visibility, chunk routing, and hydration shell alignment. Is there a known config pattern that restores chunk delivery?
Thanks in advance.

[brillout]

Seems more like a Vercel question than a Vike one. Feel free to elaborate if you believe it's somewhat related to Vike.

[KabDIY]

Thanks for the reply. I understand this may lean toward Vercel’s routing, but I believe it’s still Vike-related because:
• Vike generates the SSR entry and manifest
• Vike handles dynamic routing like /job/:id
• Vercel is returning 404 for /job/460, even though SSR is wired and /api/jobs works
I’ve confirmed:
• .vercel/output/functions/render.func/index.mjs is present and wired to server/entry.js
• Static assets are patched into .vercel/output/static/assets
• Manifest is present and hydration chunks are visible
• SSR works for /, but dynamic routes like /job/:id return 404
Is there a known issue or config pattern for Vike SSR on Vercel that ensures dynamic routes are correctly handled? I’ve tried rewrites, fallback manifests, and patching the SSR shell — but dynamic routing still fails.
Any guidance or examples from successful Vike+Vercel deployments would be hugely appreciated.

[brillout]

Given #2723 I still suspect you use AI to generate your responses. Stop doing this please. Provide minimal responses instead.

Have a look at https://vike.dev/vercel.

Then 1. fork https://github.com/brillout/vike-with-vercel, 2. create one PR to update all dependencies to their latest version, 3. check whether everything still works and report back, 4. create a second PR that reproduces your issue.

[KabDIY]

Many thanks for your response. I will do what you have said and get back. I appreciate.

[KabDIY]

Hello, I've opened the dependency upgrade PR here: https://github.com/KabDIY/JobSeekZM/pull/2
I included verification notes about the Vercel/Node 22 fix.
I will now work on the PR that reproduces my issue.
Regards.

[KabDIY]

Closing this discussion as the deployment issue is now resolved.

The key to fixing the Vercel chunk timeout/hydration error was ensuring Vercel correctly served the client-side assets alongside the serverless function. We achieved this by:

Using a Vercel-specific fork/template that correctly configured the build.

Explicitly setting the Vercel outputDirectory to dist/client (where Vike bundles client assets).

This change caused the problematic chunk files to correctly bundle within the Vercel deployment output, resolving the hydration timeout error. The issue was primarily an output configuration mismatch on Vercel.

I thank you most sincerely. Should I run into another roadblock, will come knocking again.