Skip to main content
Glama

VSCode Language Server MCP Extension

by aaddrick
GitHub
TypeScript
OverviewInspectNewEndpointsSchemaRelated ServersReviewsScore
Need Help?View Source CodeReport Issue

VSCode Language Server MCP Extension

Exposes VSCode Language Server Protocol features via MCP (Model Context Protocol) for use with Claude Code.

Overview

This VSCode extension runs an MCP server that provides access to VSCode's Language Server APIs, enabling Claude Code to:

  • Get document symbol outlines

  • Find all references to symbols

  • Rename symbols with full reference tracking

  • Get symbol definitions

  • Get hover information (types, docs)

Features

MCP Tools Provided:

  • vscode_ls_get_symbols - Get complete symbol outline of a file

  • vscode_ls_find_references - Find all references to a symbol

  • vscode_ls_rename - Safely rename symbols with reference tracking

  • vscode_ls_get_definition - Get definition location for a symbol

  • vscode_ls_get_hover - Get type information and documentation

Benefits:

  • Language-aware symbol renaming (not just find/replace)

  • Cross-file reference tracking

  • Type information from TypeScript/JavaScript language server

  • Scope-aware analysis

  • Battle-tested VSCode rename functionality

Installation

Step 1: Install Dependencies

cd ~/source/vscode-mcp-language-server npm install

Step 2: Compile TypeScript

npm run compile

Step 3: Install Extension in VSCode

Option A: Development Mode

  1. Open this directory in VSCode

  2. Press F5 to launch Extension Development Host

  3. The extension will be active in the new window

Option B: Install Locally

npm run package code --install-extension vscode-mcp-language-server-0.1.0.vsix

Configuration

The extension can be configured in VSCode settings:

{ "vscodeMcpLs.enabled": true, "vscodeMcpLs.port": 3100, "vscodeMcpLs.logLevel": "info" }

Settings:

  • enabled - Enable/disable the MCP server

  • port - Port number for MCP server (default: 3100)

  • logLevel - Logging level: debug, info, warn, error

Usage

Check Extension Status

Use the status bar item (bottom-right) or command palette:

  • VSCode MCP LS: Show Status - Display current status

  • VSCode MCP LS: Restart Server - Restart the MCP server

Connecting from Claude Code

Add to your project's MCP configuration in ~/.claude.json:

{ "projects": { "/your/project/path": { "mcpServers": { "vscode-language-server": { "type": "http", "url": "http://localhost:3100" } } } } }

Or use the CLI (note: manual configuration is currently required as claude mcp add doesn't support custom HTTP servers yet):

# Test the connection first curl http://localhost:3100 # Should return: {"name":"vscode-mcp-language-server","version":"0.1.0","status":"running","transport":"http"}

Using with Unminification Plugin

The unminification plugin skills will automatically use these tools when available:

# In analyze-minified-symbols skill: ### Step 2: Query VSCode for symbol outline Use MCP tool: \`\`\` mcp__vscode_language_server__vscode_ls_get_symbols({ "uri": "file:///path/to/minified.js" }) \`\`\` Returns: \`\`\`json { "symbols": [ { "name": "Fbr", "kind": "Variable", "range": { "start": { "line": 49, "character": 6 }, ... }, "children": [] } ] } \`\`\`

MCP Tools Reference

vscode_ls_get_symbols

Get document symbol outline.

Parameters:

{ "uri": "file:///absolute/path/to/file.js" }

Returns:

{ "symbols": [ { "name": "functionName", "kind": "Function", "range": { "start": { "line": 10, "character": 0 }, "end": {...} }, "selectionRange": {...}, "children": [...] } ] }

vscode_ls_find_references

Find all references to a symbol.

Parameters:

{ "uri": "file:///path/to/file.js", "line": 49, "character": 6 }

Returns:

{ "references": [ { "uri": "file:///path/to/file.js", "range": { "start": { "line": 49, "character": 6 }, "end": {...} } } ] }

vscode_ls_rename

Rename symbol with full reference tracking.

Parameters:

{ "uri": "file:///path/to/file.js", "line": 49, "character": 6, "newName": "isWindowsPlatform" }

Returns:

{ "success": true, "changesCount": 15, "changes": [ { "uri": "file:///path/to/file.js", "range": {...}, "newText": "isWindowsPlatform" } ] }

vscode_ls_get_definition

Get definition location for a symbol.

Parameters:

{ "uri": "file:///path/to/file.js", "line": 100, "character": 10 }

Returns:

{ "definitions": [ { "uri": "file:///path/to/file.js", "range": { "start": { "line": 49, "character": 6 }, "end": {...} } } ] }

vscode_ls_get_hover

Get type information and documentation.

Parameters:

{ "uri": "file:///path/to/file.js", "line": 100, "character": 10 }

Returns:

{ "hover": { "contents": [ { "kind": "markdown", "value": "```typescript\nconst isWindowsPlatform: boolean\n```" } ], "range": {...} } }

Development

Build

npm run compile

Watch Mode

npm run watch

Debug

  1. Open in VSCode

  2. Press F5 to launch Extension Development Host

  3. Set breakpoints in source files

  4. Extension runs with debugger attached

Testing

Test the MCP server manually:

# Start VSCode with extension # In another terminal, test connection: wscat -c ws://localhost:3100 # Send test request: { "jsonrpc": "2.0", "id": 1, "method": "tools/list" }

Architecture

VSCode Extension ├── extension.ts # Entry point, activation ├── mcpServer.ts # MCP HTTP server ├── languageServerTools.ts # VSCode API wrappers └── logger.ts # Logging utility VSCode Language Server APIs ↓ accessed via vscode.commands.executeCommand ├── vscode.executeDocumentSymbolProvider ├── vscode.executeReferenceProvider ├── vscode.executeDocumentRenameProvider ├── vscode.executeDefinitionProvider └── vscode.executeHoverProvider MCP Protocol ↓ exposed via HTTP on port 3100 Claude Code └── Uses tools via MCP client

Troubleshooting

Extension Not Starting

Check VSCode Output panel:

  1. View → Output

  2. Select "VSCode MCP Language Server" from dropdown

  3. Check for error messages

MCP Server Not Responding

  1. Check extension is enabled: vscodeMcpLs.enabled

  2. Check port is not in use: lsof -i :3100

  3. Restart server: Command Palette → "VSCode MCP LS: Restart Server"

Symbol Operations Not Working

  1. Ensure language server is active (TypeScript/JavaScript files)

  2. Check file is saved and indexed

  3. Verify file URI format: file:///absolute/path

Future Enhancements

  • Support for more language servers (Python, Go, etc.)

  • Workspace-wide symbol search

  • Code actions and quick fixes

  • Signature help

  • Completion provider access

  • Authentication for MCP connections

Contributing

Issues and pull requests welcome!

License

MIT

This server cannot be installed

-
security - not tested
F
license - not found
-
quality - not tested

How are these scores calculated?

local-only server

The server can only run on the client's local machine because it depends on local resources.

Exposes VSCode's Language Server Protocol features through MCP, enabling AI assistants to perform language-aware operations like symbol navigation, reference tracking, safe renaming, type information retrieval, and hover documentation across codebases.

  1. Overview
    1. Features
      1. Installation
        1. Step 1: Install Dependencies
        2. Step 2: Compile TypeScript
        3. Step 3: Install Extension in VSCode
      2. Configuration
        1. Usage
          1. Check Extension Status
          2. Connecting from Claude Code
          3. Using with Unminification Plugin
        2. MCP Tools Reference
          1. vscode_ls_get_symbols
          2. vscode_ls_find_references
          3. vscode_ls_rename
          4. vscode_ls_get_definition
          5. vscode_ls_get_hover
        3. Development
          1. Build
          2. Watch Mode
          3. Debug
          4. Testing
        4. Architecture
          1. Troubleshooting
            1. Extension Not Starting
            2. MCP Server Not Responding
            3. Symbol Operations Not Working
          2. Future Enhancements
            1. Contributing
              1. License

                New MCP Servers

                MCP directory API

                We provide all the information about MCP servers via our MCP API.

                curl -X GET 'https://glama.ai/api/mcp/v1/servers/aaddrick/vscode-mcp-language-server'

                If you have feedback or need assistance with the MCP directory API, please join our Discord server