Adding a language

Adding a language to PolyForge is one file. This walks through it with Elixir as the example.

1. Create a fragment in conf.d/.

   Number it for the category it belongs to — see the merge model for why the number matters.

   .config/mise/conf.d/40-elixir.toml

   [tools]
   erlang = "latest"
   elixir = "latest"

   The tool is now declared workspace-wide: every directory in the tree, at any depth, has it in scope.

2. Add a workspace area (optional).

   If you want a home for Elixir projects with its own environment or tasks:

   Workspace/Elixir/mise.toml

   [env]
   MIX_ENV = "dev"
   
   [tasks.test]
   run = "mix test"

   This file inherits everything from the root mise.toml and the conf.d fragments, and overrides only what it names.

3. Install.

   polyforge install

4. Verify.

   polyforge status

Choosing the number prefix

Range	Category	Examples
00-	Global settings	jobs, auto_install
10-	Language interpreters and compilers	python, go, rust, node, java
20-	CLI toolbelt	eza, bat, ripgrep, fd, jq, delta
30-	Package managers and build tools	bun, pnpm, uv, cmake, ninja
40-+	Everything you add	elixir, database clients, cloud CLIs

Two rules keep this predictable:

• A tool belongs to exactly one fragment. Declaring it twice means the later file silently wins.
• Depend forward, not backward. If tool B needs tool A, A’s fragment must sort earlier.

Should it go in conf.d/ or a nested mise.toml?

Ask where you want the tool available.

• Everywhere in the workspace → conf.d/. This is right for interpreters and anything you use daily.
• Only inside one language area → Workspace/<Lang>/mise.toml. Right for a heavy, narrow tool that would otherwise cost every polyforge install time and disk.

Not sure?

Start in the language area. Promoting a fragment to conf.d/ later is a file move; demoting one after everyone has come to rely on it is a change in behaviour.

Removing a language

Delete the fragment, then:

polyforge install    # reconcile the declared set
polyforge clean      # reclaim cache

Removing the declaration does not uninstall what mise already fetched. Use polyforge clean --all for a genuinely clean slate — it runs mise implode and removes every installed toolchain, not just this one.