Unable to override basepath for api routes

[aarjithn]

Which project does this relate to?

Start

Describe the bug

It is sometimes required to setup tanstack start app with a basepath.
For the router, it is possible to pass a basepath to createTanStackRouter
For server fns, it is possible to set this in app.config.ts

  routers: {
    server: {
      base: '/path/_server',
    },

However, the config apiBase doesn't seem to work with a custom basepath.

tsr: {
    apiBase: '/api',
    // apiBase: '/path/api', <- throws 503 Server unavailable
  },

And this makes it impossible to define api routes inside a subpath.

Your Example Website or App

https://stackblitz.com/edit/tanstack-router-rfnhqhpv?file=app.config.ts

Steps to Reproduce the Bug or Issue

1. In attached stackblitz, update apiBase with a base url (uncomment line 25 - /path/api)
2. Note error 503 Server Unavailable

Expected behavior

Should be able to provide a custom basepath for api routes, like the router itself

Screenshots or Videos

Platform

• OS: macOS
• Browser: Chrome

Additional context

No response

[SeanCassiere]

Once you've changed the apiBase to /path/api, you need to change and update your API route files to match the new pathing.

So, these files need to have their locations changed as well. So in app/routes,

Old Location	New Location	Alternate Location
api/users.ts	path/api/users.ts	path.api/users.ts
api/users.$id.ts	path/api/users.$id.ts	path.api/users.$id.ts

[aarjithn]

@SeanCassiere Thank you for responding - do you think it is a bit confusing because we don't have to do that for file routes, only API routes?

i.e, for file routes base path prefix is "automatic" once added in config, no need to rename files themselves

[SeanCassiere]

@SeanCassiere Thank you for responding - do you think it is a bit confusing because we don't have to do that for file routes, only API routes?

i.e, for file routes base path prefix is "automatic" once added in config, no need to rename files themselves

Not in my opinion, since file routing also uses the similar keys which require changes to your file structure.

That being said, we are exploring other ways doing API routes that could make this easier.