mcp-lsp-bridge

It is like "Rename/go to reference" for Claude Code.

An MCP server that bridges AI coding assistants to TypeScript's Language Server (tsserver), enabling semantic code navigation, reference finding, and refactoring.

Unlike text-based search (ripgrep), this server provides semantically-aware results — no false positives from comments or strings, proper import resolution, and accurate type-aware symbol tracking.

Benchmark

Tested on a real TypeScript monorepo (423 files, 4 packages). Task: rename a type property referenced across 118 files with 1,000+ occurrences.

| Metric | Claude | MCP-LSP Bridge | Improvement | |--------|--------|----------------|-------------| | Time | 160 sec | 22 sec | 7x faster | | Tool calls | 41 | 4 | 10x fewer | | Tokens | ~6,300 | ~12 | 500x fewer | | Cost | ~$2.20 | ~$0.15 | 93% savings |

One MCP tool call replaces an entire chain of grep/read/edit steps — faster, cheaper, and more accurate.

How It Works

This project is a bridge, not a language server itself. It wraps TypeScript's own language server (tsserver) and exposes its capabilities as MCP tools. The bridge manages tsserver processes automatically — you don't need to start or configure anything yourself.

┌─────────────────────────────────────────────────────┐
│  VS Code                                            │
│  ┌───────────────┐    ┌────────────────────────────┐│
│  │  Editor       │    │  Claude Code (terminal)    ││
│  │               │    │                            ││
│  │  Built-in     │    │  Uses MCP tools instead of ││
│  │  IntelliSense │    │  grep/read for navigation  ││
│  └──────┬────────┘    └────────────┬───────────────┘│
│         │                          │                │
│         ▼                          ▼                │
│    VS Code's                 mcp-lsp-bridge         │
│    tsserver                  (this project)         │
│    (built-in)                      │                │
│                                    ▼                │
│                              Its own tsserver       │
│                              (spawned on demand)    │
└─────────────────────────────────────────────────────┘

VS Code already gives you IntelliSense through its built-in tsserver. This project gives Claude the same semantic understanding through its own tsserver instance, so it can navigate your code as precisely as your IDE does.

Example: VS Code + Claude Code

1. You're editing a TypeScript monorepo in VS Code
2. You open the integrated terminal and run Claude Code
3. You ask Claude to rename a type property used across 118 files
4. Without mcp-lsp-bridge: Claude uses grep to find the symbol, reads each file, edits them one by one — 41 tool calls, ~160 seconds, $2.20
5. With mcp-lsp-bridge: Claude calls rename_symbol once and updates every reference instantly — 4 tool calls, ~22 seconds, $0.15

Tools

| Tool | Description | Modifies Files | |------|-------------|----------------| | find_references | Locate all references to a symbol | No | | go_to_definition | Navigate to symbol definition | No | | rename_symbol | Rename symbol across project | Yes | | get_diagnostics | Get compilation errors/warnings | No |

Installation

npm install -g mcp-lsp-bridge

Or use directly with npx:

npx mcp-lsp-bridge

Configuration

Claude Code

Add to your Claude Code MCP settings:

{
  "mcpServers": {
    "mcp-lsp-bridge": {
      "command": "npx",
      "args": ["mcp-lsp-bridge"]
    }
  }
}

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "mcp-lsp-bridge": {
      "command": "npx",
      "args": ["mcp-lsp-bridge"]
    }
  }
}

Usage

All tools accept a workspaceRoot (absolute path to your project) and file positions use 1-based line and column numbers.

find_references

Find all usages of a symbol across the project.

{
  "workspaceRoot": "/path/to/project",
  "filePath": "src/utils.ts",
  "line": 5,
  "column": 17
}

Returns references with file paths, positions, code snippets, and whether each is a declaration or usage.

go_to_definition

Jump to where a symbol is defined.

{
  "workspaceRoot": "/path/to/project",
  "filePath": "src/app.ts",
  "line": 10,
  "column": 3
}

Returns definition location(s), including external definitions in node_modules or .d.ts files.

rename_symbol

Rename a symbol and update all references across the project.

{
  "workspaceRoot": "/path/to/project",
  "filePath": "src/models.ts",
  "line": 8,
  "column": 14,
  "newName": "updatedName"
}

Modifies files on disk and returns a report of all changes made.

get_diagnostics

Get TypeScript compilation errors and warnings.

{
  "workspaceRoot": "/path/to/project",
  "filePath": "src/index.ts"
}

Omit filePath for project-wide diagnostics. Returns severity, diagnostic codes, and code snippets.

Supported Projects

• TypeScript projects (tsconfig.json)
• JavaScript projects (jsconfig.json)
• Monorepos (Nx, Turborepo) with multiple tsconfig files
• Mixed TypeScript/JavaScript codebases
• All standard file extensions: .ts, .tsx, .js, .jsx, .mts, .cts, .mjs, .cjs, .d.ts

Development

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

# Development mode (watch)
npm run dev

Architecture

AI Client  <-->  MCP Server  <-->  tsserver (stdin/stdout)
              (this project)     (TypeScript language server)

The server manages tsserver instances per workspace, caching them for subsequent requests.

License

MIT