I am in a similar situation and have been thinking about this, your post got me to actually get off my butt and try it. Make a blank project. I called mine “test” then I changed Test.hello/1 to IO.puts :world instead of return :world Then mix release, and do _build/dev/rel/test/bin/test eval "Testy.hello" And it does exactly what you expect!

If you’re on linux and you really wanted to be sophisticated about delivery you could put it into a podman container or something and roll it into a single binary, but if you don’t need to roll up a single container (or don’t have the luxury of being in linux) it should be pretty easy to roll up a shell script that will do roll up parameters into the right thing using a release.

Don’t forget to add EEx to your list of :extra_applications in Mix.exs if it needs to be there at runtime. Though I feel like it’s generally better to make it so all of your EEx code runs at compile time, if that’s possible for what you’re doing.