LSPs

Crush can use LSPs (Language Server Protocol implementations) for additional context to help inform its decisions, just like you would.

Configuration

LSPs can be added manually in your crush.json:

{
  "$schema": "https://charm.land/crush.json",
  "lsp": {
    "go": {
      "command": "gopls",
      "env": {
        "GOTOOLCHAIN": "go1.24.5"
      }
    },
    "typescript": {
      "command": "typescript-language-server",
      "args": ["--stdio"]
    },
    "nix": {
      "command": "nil"
    }
  }
}

Each entry is keyed by a language identifier. The available fields are:

Field	Type	Required	Description
command	string	Yes	The executable to run
args	string[]	No	Arguments passed to the command
env	object	No	Environment variables for the server

Auto-Discovery

Crush attempts to auto-discover LSPs for common languages. If an LSP binary is found on your PATH, Crush will start it automatically when working with files of that language.

Debugging LSP Connections

If an LSP isn't working as expected, enable debug logging:

{
  "$schema": "https://charm.land/crush.json",
  "options": {
    "debug_lsp": true
  }
}

Then check the logs with crush logs --follow.