@orkestrel/lsp

A typed Language Server Protocol client over an injected byte transport: a host-independent core carrying the base-protocol framing codec, the JSON-RPC and protocol guards, and an LSPClient that completes the initialize handshake, owns opened document URIs, and selects pull or push diagnostics from the server's own capabilities, beside a server environment whose StdioClientTransport carries those bytes over a language server run as a child process.

Create a client with the createLSPClient function, hand it a transport, and call start() before you open a document. The client reaches its peer only through the transport it is handed, so any implementation of LSPTransportInterface drives the same client, and the stdio transport ends the child's whole tree inside a bounded termination window. Part of the @orkestrel line.

Install

npm install @orkestrel/lsp

Requirements

• Node.js >= 22.12.0
• ESM and CommonJS builds for the . and ./server entry points
• TypeScript moduleResolution set to node16, nodenext, or bundler

Usage

import { createLSPClient } from '@orkestrel/lsp'
import { createStdioClientTransport } from '@orkestrel/lsp/server'
import { pathToFileURL } from 'node:url'

declare const directory: string

const transport = createStdioClientTransport({
	server: { command: ['my-language-server', '--stdio'], directory },
	grace: 5_000,
})
const client = createLSPClient({ transport, workspace: pathToFileURL(directory).href })
await client.start()
await client.destroy()

Guide

For the full surface — the client lifecycle, the transport seam, the stdio child transport, the framing codec and its retained decode state, the protocol guards, and the LSPError failure type — see the Language Server Protocol client guide.

Package

Typed entry points per the exports field in package.json: the host-independent client, framing codec, guards, constants, and LSPError from @orkestrel/lsp, and the Node stdio transport — StdioClientTransport and createStdioClientTransport — from @orkestrel/lsp/server.

License

MIT © Orkestrel — see the license.