Provide full URL of deployed app in Environment

I have a NextJS app running as frontend (FE) with a Ruby on Rails app as backend (BE) API server.
The FE needs the URL of the BE.
Unfortunately, I can only alias an environment variable to the BE HOST. As I understand that env vars substitution is not yet available, I cannot create an URL from the BE HOST (such as https://${BE_HOST} for exemple.

So can you provide the full URL of the instance of a deployed app so we can create an alias on it ?


Hi @emmanuelcohenlaroque ,

I am looking with the team since it’s a very common request (until we support environment variable substitution/interpolation).

In the meantime, I would highly suggest creating your expected environment variable in your Dockerfile. E.g. you can do this:

FROM ...


... your build commands

This way for your application it’s transparent.