#1722 · stacks/stx

Summary

The production server's 404 path correctly looks up the user's 404.stx page (if present) via exactRoutes.get('/404'). The 500 path at packages/stx/src/production-server.ts:266 does NOT do the equivalent — it returns plain text:

return new Response('Internal Server Error', { status: 500 })

A project that ships pages/500.stx for branded error UI still gets an unbranded "Internal Server Error" string when the server hits an exception.

Reproducer

my-app/
  pages/
    500.stx   ← user's custom error page
  stx.config.ts

Build and run via stx start. Force any server-side error (corrupted manifest entry, throw in route middleware, etc.). Response body is text/plain "Internal Server Error", not the rendered 500.stx.

Root cause

packages/stx/src/production-server.ts:228-239 — for 404:

const notFoundRoute = exactRoutes.get('/404')
if (notFoundRoute) {
  const compiled = compiledTemplates.get(notFoundRoute.filePath)
  if (compiled) {
    return new Response(compiled.html, {
      status: 404,
      headers: { 'Content-Type': 'text/html; charset=utf-8' },
    })
  }
}
return new Response('Not Found', { status: 404 })

But the corresponding fallback at line 266 has no such lookup — it skips straight to plain text.

Impact

Branded 500 pages don't work in production.
Inconsistency with the 404 path is confusing.
Apps relying on pages/500.stx for legal/branding reasons silently regress on errors.

Suggested fix

Mirror the 404 pattern:

const errorRoute = exactRoutes.get('/500')
if (errorRoute) {
  const compiled = compiledTemplates.get(errorRoute.filePath)
  if (compiled) {
    return new Response(compiled.html, {
      status: 500,
      headers: { 'Content-Type': 'text/html; charset=utf-8' },
    })
  }
}
return new Response('Internal Server Error', { status: 500 })

Worth confirming with the same treatment whether any other error responses (502/503/504) should also support custom pages from the user's pages/ tree.

Environment

stx main
Bun 1.3.13