@MaximDementyev right now, im reviewing smaller PRs, I need enough time for focus to review this, so it can take time. I have not forgotten about this one)

The FastApi 0.137.0 update has broken the routers.routers traversal logic.
It will take some time to figure out how to fix this.

If implementing any url search logic seems complicated, you can consider creating a function like this:

def local_url_for(request, name, **kwargs):
   return request.url_for(f"admin:{name}", **kwargs)

This will allow you to collect all the URL search logic in one place, giving users the ability to override this function.
It is very difficult to redefine url_for now, as it affects many files.

This is incomplete. I am putting this to draft for now. Here are things that should be considered/fixed

1. Document breaking changes (especially moving from classvar to object var, i.e. session_maker
2. The other classvars are still being overriden:

view._admin_ref = self
view.is_async = self.is_async
view.ajax_lookup_url = urljoin(
        self.base_url + "/", f"{view.identity}/ajax/lookup"
)
view.templates = self.templates
view_instance = view(self.session_maker)

So if two admin have different ajax_lookup_urls, it will be messed up

3. For backwards compatibility, user overriden templates should work. As of today, if user overrode template, it will be admin:admin:list.

4. Document mount_name param, both in markdown and in the code

5. Add tests that have two admins

6. docs/authentication.md and docs/configurations.md still tell users to write request.url_for("admin:index")

7. If there is unnamed mounts, in get_current_router_name, a nested match returns f"{router.name}:{sub_name}" — if the intermediate Mount has no name, that's the literal string "None:admin", and URL generation blows up.

8. Dead comparison in the first loop. for router in getattr(start_router, "routes", []): if router == target_router compares a Route/Mount against a Router — never true.

9. O(route-tree) walk per generated URL. A list page emits dozens of URLs (per-row view/edit/delete, pagination, exports, statics ×13); each one recursively walks the host app's entire route tree. On a large FastAPI app that's thousands of comparisons per request for a value that never changes. The prefix is static — compute it once at mount time (the Admin literally receives mount_name as a parameter!) or cache it in request.scope on first use.

OR:

Inside an admin request, request.app is the admin's Starlette app, so request.app.url_path_for(name, **params).make_absolute_url(request.base_url) produces the correct URL with no name-prefix discovery, no mount_name uniqueness requirement, no tree walk