Which integrations are available for this server?

Exposes [TypeScript](/mcp/servers/integrations/typescript) LSP-like functionality including type inspection, definition lookup, references finding, hover documentation, diagnostics, and type testing capabilities for TypeScript projects.

ts-lsp-mcp

npm version npm downloads license

MCP server exposing TypeScript LSP-like functionality to AI agents.

Gives AI agents the same "what's the type at this position?" powers that IDE users have.

Quick Start

Install into Claude Code

# Install to current project (recommended) npx ts-lsp-mcp install cc # Or install globally for all projects npx ts-lsp-mcp install cc --global

That's it! The MCP server is now available to Claude Code.

Uninstall

npx ts-lsp-mcp uninstall cc

Manual Installation

Global npm install

npm install -g ts-lsp-mcp ts-lsp-mcp install cc

Manual config

Add to your Claude Code MCP config (.mcp.json in project or ~/.claude/settings.json globally):

{ "mcpServers": { "ts-lsp-mcp": { "type": "stdio", "command": "npx", "args": ["-y", "ts-lsp-mcp", "serve", "--stdio"] } } }

HTTP/SSE Mode

For remote clients or debugging:

ts-lsp-mcp --http --port 3000

Endpoints:

GET /sse - SSE connection
POST /message - Send messages
GET /health - Health check

Available Tools

Tool	Description
`getTypeAtPosition`	Get the TypeScript type at a specific file:line:col
`getDefinition`	Go to definition
`getReferences`	Find all references
`getHover`	Get hover documentation
`getCompletions`	Get autocomplete suggestions
`getDiagnostics`	Get type errors and warnings
`traceType`	Trace where a type comes from and how it's composed
`runTypeTests`	Run type assertions from `@ts-lsp-mcp` comments
`checkInlineCode`	Type-check inline TypeScript without creating files

Type Test Assertions

Add type assertions to your code:

// @ts-lsp-mcp expect-type: string const name = user.name; // @ts-lsp-mcp expect-type: User const user = createUser({ name: 'Alice' }); // @ts-lsp-mcp expect-error: 2322 const bad: number = "oops"; // Should have error 2322

Run tests:

runTypeTests({ file: "src/types.ts" }) runTypeTests({ pattern: "**/*.type-test.ts" })

Example Usage

Get type at position

Supports unified file:line:col format:

{ "tool": "getTypeAtPosition", "arguments": { "file": "src/user.ts:10:5" } }

Or separate parameters:

{ "tool": "getTypeAtPosition", "arguments": { "file": "src/user.ts", "line": 10, "col": 5 } }

Response:

{ "type": "User", "expanded": "{ id: number; name: string; email: string }", "symbol": "user", "kind": "variable" }

Check for type errors

{ "tool": "getDiagnostics", "arguments": { "file": "src/user.ts" } }

Type-check inline code

{ "tool": "checkInlineCode", "arguments": { "code": "const x: number = 'bad';" } }

Response:

{ "valid": false, "diagnostics": [{ "line": 1, "col": 7, "code": 2322, "message": "Type 'string' is not assignable to type 'number'." }] }

Features

Multi-project support: Works with monorepos with multiple tsconfigs
Auto-discovery: Finds tsconfig.json automatically
Smart file resolution: Accepts absolute, relative, or unique filenames
Virtual files: Type-check unsaved code with the content parameter
Efficient: Long-lived daemon caches TypeScript projects

CLI Options

ts-lsp-mcp [command] [options] Commands: serve Start the MCP server (default) install <target> Install into an AI assistant (cc, claude-code, claude) uninstall <target> Uninstall from an AI assistant Serve options: --stdio Use stdio transport (default) --http Use HTTP/SSE transport --port <port> HTTP server port (default: 3000) --host <host> HTTP server host (default: 127.0.0.1) --debug Enable debug logging Install options: --global Install globally (user scope) instead of project --name <name> Custom name for the MCP server (default: ts-lsp-mcp) General: -V, --version Output version number -h, --help Display help

License

MIT

TypeScript LSP MCP