# Edge Function returns 404

> Fix 404 responses from SupaHost Edge Functions: NOT_FOUND from the router, a wrong URL or slug, a function that never deployed, or a 404 returned by your own routing code.

Source: https://supahost.app/kb/function-404 · Updated 2026-11-11

## What you see

A call to your function returns `404`. There are three different 404s, and the response tells you which one you hit:

```text
HTTP/2 404
sb-error-code: NOT_FOUND
```

```text
HTTP/2 404
no Route matched with those values
```

Or a 404 with no `sb-error-code` header and a body your own code produced.

## Why it happens

- **`sb-error-code: NOT_FOUND`**: the request reached the function router, but no active function has that slug in this project. The slug is misspelled, the function was deleted, its first deploy failed so no version is live, or you're calling the wrong project.
- **`no Route matched with those values`**: the path didn't start with `/functions/v1/`, so the gateway didn't send it to functions at all. For example `https://app-one.acme.supahost.space/send-invoice`.
- **No `sb-error-code`**: your function ran and returned 404 itself, usually because its internal router didn't match the path it received.

## How to fix it

1. **Check the URL format.** It's always:

   ```text
   https://<project>.<instance>.supahost.space/functions/v1/<slug>
   ```

   For project `app-one` on instance `acme` and a function `send-invoice`: `https://app-one.acme.supahost.space/functions/v1/send-invoice`. With supabase-js, pass only the slug: `supabase.functions.invoke('send-invoice')`.
2. **Check the slug.** Slugs are lowercase letters, digits, `-` and `_`. `sendInvoice` and `send-invoice` are different. Compare with the list in *Dashboard → your project → **Functions** tab*.
3. **Check the status.** In the Functions tab, the function must be `active`. If its only version is `error`, nothing is serving yet; fix the build and deploy again (see [Edge Function deploy failed](/kb/function-deploy-failed)). A function that's still `deploying` also isn't live yet.
4. **Check the project.** Make sure your app's `SUPABASE_URL` points at the project that has the function. Branches don't copy functions from their parent, so a branch needs its own deploy.
5. **Debug your own routing.** If the 404 came from your code, log the path your handler sees and adjust your matching:

   ```ts
   Deno.serve((req) => {
     const { pathname } = new URL(req.url)
     console.log('path received:', pathname)
     if (pathname.endsWith('/health')) return new Response('ok')
     return new Response('Not found', { status: 404 })
   })
   ```

   The log line appears in the Functions tab's Logs card.

## On SupaHost

The router answers `NOT_FOUND` with JSON and the `sb-error-code` header. If a project has no functions at all yet, `/functions/v1/*` also returns a 404 JSON response. Custom domains work too: once a custom domain is active, `https://api.yourapp.com/functions/v1/<slug>` reaches the same function.

## Related

- [Deploying functions](/docs/functions/deploying)
- [Calling functions from your app](/docs/functions/calling-functions)
- [Edge Function deploy failed](/kb/function-deploy-failed)
- [Logs and debugging](/docs/functions/logs)