Config routes and path helpers

[International]

How are you guys storing your config options? For example, consider this snippet:

config :coherence,
  logged_in_url: "/projects"

I'd like not to have to hardcode the path in there ( config/config.exs ), but if I have it like this:

logged_in_url: Helpers.project_path(XtimersWeb.Endpoint, :index)

I get an error saying:

module XtimersWeb.Router.Helpers is not available

My guess is that it's because phoenix generates this? Another option would probably be an environment variable, but that too might get out of syncs with the routes. Is there a better way?