Admin catch-all route /_emdash/admin/[...path] returns 404 for all sub-paths

[diegoesolorzano]

Description

The admin SPA catch-all route /_emdash/admin/[...path] is registered in the Astro manifest during build but returns 404 for ALL sub-paths (/setup, /login, /content, etc.).

API routes under /_emdash/api/* work correctly (return 401/200).

Environment

• Emdash: 0.1.0
• Astro: 6.1.4
• Node: 24.13.1
• OS: macOS ARM64
• Tested with both @astrojs/cloudflare and @astrojs/node adapters — same result

Steps to Reproduce

1. Create project from marketing-cloudflare template
2. Run npx emdash init && npx emdash seed seed/seed.json
3. Run npx emdash dev --port 4321
4. Visit http://localhost:4321/_emdash/admin
5. Get redirected to /_emdash/admin/setup (correct)
6. /_emdash/admin/setup returns 404 (broken)

Investigation

• The route IS in the build manifest with correct pattern /_emdash/admin/[...path] and component path to admin.astro
• The admin.astro file exists and resolves correctly via require.resolve('emdash/routes/admin.astro')
• The setup middleware correctly redirects to /setup when no users exist
• API routes injected the same way work perfectly
• Creating a manual src/pages/admin/[...path].astro also returns 404 — this might be an Astro 6 issue with catch-all routes in injected paths

Expected Behavior

/_emdash/admin/setup should render the admin SPA shell (admin.astro).

Workaround

None found. The admin panel is completely inaccessible.

[diegoesolorzano]

Update: This appears related to known Astro issues with injectRoute and route priority — withastro/astro#3809 and withastro/astro#6221. The Astro i18n config with prefixDefaultLocale may create internal routing that intercepts the injected admin catch-all route. API routes work because they are endpoints not pages. Tested with both Cloudflare and Node adapters — same 404.

[diegoesolorzano]

Root cause confirmed

The Astro native i18n config in astro.config.mjs breaks all injected catch-all page routes from integrations, including /_emdash/admin/[...path].

// This config causes the admin catch-all to return 404:
i18n: {
  defaultLocale: "es",
  locales: ["es", "br"],
  routing: { prefixDefaultLocale: true },
  fallback: { br: "es" },
},

API endpoint routes (/_emdash/api/*) are NOT affected — only page routes with spread params.

Workaround

Remove the i18n key from astro.config.mjs and handle i18n manually with /es/ and /br/ page folders. The admin panel works immediately after removing it.

Setting routing: "manual" does NOT work as a workaround — it requires implementing a custom i18n middleware, which adds complexity.

Reproduction

1. Create any Emdash project with i18n config in astro.config.mjs
2. npx emdash dev
3. Visit /_emdash/admin → redirects to /setup → 404
4. Remove i18n config → restart → admin works (200)

Related Astro issues:

• 🐛 BUG: injectRoute path intercepted by dynamic route during dev withastro/astro#3809
• custom integration: injected catch-all route overwrites local routes withastro/astro#6221