LSP Servers

Plugins can provide Language Server Protocol (LSP) server configurations to give agents real-time code intelligence — diagnostics, go-to-definition, find references, and hover information.

Important: Binary Not Bundled

LSP plugins configure how the host tool connects to a language server. They do not bundle the language server binary itself. Users MUST install the required language server separately.

Configuration Format

LSP servers are configured in .lsp.json at the plugin root.

{
  "go": {
    "command": "gopls",
    "args": ["serve"],
    "extensionToLanguage": {
      ".go": "go"
    }
  },
  "python": {
    "command": "pyright-langserver",
    "args": ["--stdio"],
    "extensionToLanguage": {
      ".py": "python",
      ".pyi": "python"
    }
  }
}

Note: unlike MCP servers, the top-level object does not have a wrapping key. The keys are the server names directly.

Server Configuration Schema

Required Fields

Field	Required	Type	Description
`command`	Yes	string	The LSP binary to execute. Must be on `$PATH`.
`extensionToLanguage`	Yes	object	Maps file extensions (with dot) to language identifiers.

Optional Fields

Field	Type	Default	Description
`args`	string[]	`[]`	Command-line arguments.
`transport`	`"stdio"` \| `"socket"`	`"stdio"`	Communication transport.
`env`	object	`{}`	Environment variables.
`initializationOptions`	object	`{}`	LSP initialization options.
`settings`	object	`{}`	Settings via `workspace/didChangeConfiguration`.
`restartOnCrash`	boolean	`false`	Auto-restart on crash.
`maxRestarts`	number	—	Max restart attempts.

Capabilities

Capability	LSP Method	Description
Diagnostics	`textDocument/publishDiagnostics`	Errors and warnings after edits
Go to definition	`textDocument/definition`	Navigate to symbol definitions
Find references	`textDocument/references`	Find all usages of a symbol
Hover	`textDocument/hover`	Type information and documentation

Lifecycle

LSP servers MUST start when the plugin is enabled and matching files are present.
LSP servers MUST stop when the plugin is disabled or the session ends.
If the binary is not found, the tool MUST log a clear error and continue.

Compatibility

This spec does not redefine the Language Server Protocol. Plugin LSP servers MUST communicate using the LSP specification.

LSP Servers

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