[Bug?]: API routes not matched when server.baseURL is set #2106

Duplicates

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Latest version

• I have tested the latest version

Current behavior 😯

When server.baseURL is configured in the Vinxi/SolidStart config (e.g. server: { baseURL: '/admin' }), API routes defined in src/routes/ are never matched. Requests to /admin/api/my-route fall through to the page renderer and return a 404 HTML response instead of executing the API handler.

The root cause is in @solidjs/start/dist/server/handler.js:

// line 29
const match = matchAPIRoute(new URL(event.request.url).pathname, event.request.method)

event.request.url contains the full pathname including the baseURL prefix — e.g. /admin/api/my-route. However, matchAPIRoute looks up routes registered from the file system, which are stored without the prefix (e.g. /api/my-route). The lookup always fails, so all API routes become unreachable.

Expected behavior 🤔

API routes defined in src/routes/api/ should be matched and executed correctly regardless of the server.baseURL setting. matchAPIRoute should strip the server.baseURL prefix from the pathname before performing the route lookup — the same way @solidjs/router's base prop strips it for page route matching on the client.

Steps to reproduce 🕹

Steps:

1. Create a SolidStart app with server.baseURL set:

// app.config.ts
import { defineConfig } from '@solidjs/start/config'
export default defineConfig({
  server: { baseURL: '/app' },
})

2. Add base to the Router so page navigation works:

// src/app.tsx
<Router base={import.meta.env.SERVER_BASE_URL}>
  <FileRoutes />
</Router>

3. Create an API route:

// src/routes/api/hello.ts
export function GET() {
  return new Response(JSON.stringify({ ok: true }), {
    headers: { 'Content-Type': 'application/json' },
  })
}

4. Start the dev server and request GET /app/api/hello

Result: 404 — the SPA catch-all ([...404]) renders instead of the API handler.
Expected: 200 { "ok": true }

Context 🔦

Workaround: Move the route file to mirror the full path including the base — src/routes/app/api/hello.ts — so the registered route path /app/api/hello matches what matchAPIRoute receives. This is unergonomic and forces duplication of the base prefix in the file structure.

Your environment 🌎