Nginx 502 Bad Gateway error when proxying prerendered pages with Cloudflare Pages

[mladenovic-13]

Which project does this relate to?

Start

Describe the bug

When enabling prerendering for marketing pages in a TanStack Start application deployed to Cloudflare Pages, nginx reverse proxy returns 502 Bad Gateway errors when accessing these prerendered routes.

Your Example Website or App

/

Steps to Reproduce the Bug or Issue

1. Enable prerendering in vite.config.ts:

tanstackStart({
  target: 'cloudflare-pages',
  pages: [
    { path: '/', prerender: { enabled: true, crawlLinks: false } },
    { path: '/about-us', prerender: { enabled: true, crawlLinks: false } },
    { path: '/careers', prerender: { enabled: true, crawlLinks: false } },
    // ... other marketing pages
  ],
})

2. Build the application: npm run build
3. Deploy to Cloudflare Pages
4. Set up nginx reverse proxy to Cloudflare Pages worker
5. Access any prerendered route (e.g., /about-us)

Expected behavior

Prerendered pages should be served correctly through nginx proxy.

Screenshots or Videos

No response

Platform

• OS: macOS
• Browser: Chrome

Additional context

No response