Setting up elixir-ls

  1. Install elixir:
brew install elixir
  1. Install elixir-ls:
brew install elixir-ls
  1. Restart Zed

If elixir-ls is not running in an elixir project, check the error log via the command palette action zed: open log. If you find an error message mentioning: invalid LSP message header "Shall I install Hex? (if running non-interactively, use \"mix local.hex --force\") [Yn], you might need to install Hex. You run elixir-ls from the command line and accept the prompt to install Hex.

Formatting with Mix

If you prefer to format your code with Mix, use the following snippet in your settings.json file to configure it as an external formatter. Formatting will occur on file save.

  "languages": {
    "Elixir": {
      "format_on_save": {
        "external": {
          "command": "mix",
          "arguments": ["format", "--stdin-filename", "{buffer_path}", "-"]

Additional workspace configuration options (requires Zed 0.128.0):

You can pass additional elixir-ls workspace configuration options via lsp settings in settings.json.

The following example disables dialyzer:

"lsp": {
  "elixir-ls": {
    "settings": {
      "dialyzerEnabled": false

See ElixirLS configuration settings for more options.