lsp-tools-mcp

Standalone Language Server Protocol tools exposed as a stdio MCP server.

Used By

This repository is the upstream source of truth for two downstream plugins. Both consume it as a git submodule:

Project	Path	Role
codex-lsp	packages/lsp-tools-mcp/	Codex plugin that ships these LSP MCP tools plus a Codex-specific PostToolUse diagnostics hook.
oh-my-openagent (a.k.a. oh-my-opencode)	vendor/lsp-tools-mcp/	OpenCode plugin that registers this server as a built-in Tier-1 stdio MCP. Exposes lsp_diagnostics, lsp_goto_definition, lsp_find_references, lsp_symbols, lsp_prepare_rename, lsp_rename, and lsp_status to all agents.

If you fix or extend the LSP runtime here, both downstreams pick up the change by bumping the submodule pointer. Do not fork the runtime into a downstream; land changes here instead.

Quick Start

npm install
npm run check
npm test
npm run build
printf '%s\n' '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | node dist/cli.js mcp

MCP Tools

This server exposes the following tools:

• lsp.status
• lsp.diagnostics
• lsp.goto_definition
• lsp.find_references
• lsp.symbols
• lsp.prepare_rename
• lsp.rename

Tool aliases are also available for compatibility:

• lsp_status
• lsp_diagnostics
• lsp_goto_definition
• lsp_find_references
• lsp_symbols
• lsp_prepare_rename
• lsp_rename

When an MCP host registers this server under the name lsp (the default in both downstreams), the tools are exposed to agents as lsp_status, lsp_diagnostics, and so on, matching the alias names above.

Configuration

Default config paths (matches codex-lsp's historical layout):

• Project: .codex/lsp-client.json
• User: ~/.codex/lsp-client.json

Path overrides via environment variables:

• LSP_TOOLS_MCP_PROJECT_CONFIG
• LSP_TOOLS_MCP_USER_CONFIG

Examples (oh-my-openagent points the project config at .opencode/lsp.json via the env var):

LSP_TOOLS_MCP_PROJECT_CONFIG=.opencode/lsp.json node dist/cli.js mcp
LSP_TOOLS_MCP_USER_CONFIG=.opencode/lsp.json node dist/cli.js mcp

Example config file:

{
	"lsp": {
		"typescript": {
			"command": ["typescript-language-server", "--stdio"],
			"extensions": [".ts", ".tsx", ".js", ".jsx"]
		}
	}
}

Architecture

• src/lsp/* standalone LSP runtime (process management, JSON-RPC transport, configuration, diagnostics, workspace edits)
• src/tools.ts MCP tool definitions and handlers
• src/mcp.ts stdio MCP server entry and registration
• src/cli.ts standalone CLI entry (mcp subcommand only)

Local Development

npm install
npm run check
npm test
npm pack --dry-run

License

MIT