VS MCP Server

Model Context Protocol (MCP) server for Visual Studio — Enables AI agents like Claude Code to control Visual Studio features including debugging, building, editing, and UI automation.

This is a beta release. Feedback and bug reports are welcome on GitHub Issues.

100% AI Generated — All code in this project was generated entirely by AI (Claude).

Features

VS MCP Server exposes 106 tools across the following categories:

Tool Details

General

Solution

Project

Build

Editor

Edit Preview

Code Navigation

Solution Explorer

Debugger

Breakpoint

Output & Diagnostics

Console

UI Automation

Watch

Thread

Process

Immediate

Module

Register

Exception

Memory

Parallel

Web

Test

NuGet

Requirements

• Visual Studio 2019 (16.0 or later), Visual Studio 2022, or Visual Studio 2026 — Community, Professional, or Enterprise edition
• Windows
• .NET Framework 4.8
• .NET 8.0 Runtime (for the StdioProxy component)

Installation

1. Install the extension from Visual Studio Marketplace or download the .vsix file from Releases
2. Restart Visual Studio
3. The MCP server starts automatically when Visual Studio launches

Setup — Connecting with Claude Code

Note: %LOCALAPPDATA% is not recognized in bash. You must specify the full absolute path (e.g. C:\Users\<USERNAME>\AppData\Local\...).

Option A — CLI command:

claude mcp add vs-mcp -- "C:\Users\<USERNAME>\AppData\Local\VsMcp\bin\VsMcp.StdioProxy.exe"

Option B — Manual configuration (add to your MCP config JSON):

{
  "mcpServers": {
    "vs-mcp": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe"
    }
  }
}

Architecture

The extension runs an HTTP-based MCP server inside Visual Studio. A lightweight StdioProxy bridges stdio-based MCP clients (like Claude Code) to the HTTP server, enabling seamless communication.

Claude Code  ──stdio──▶  StdioProxy  ──HTTP──▶  VS Extension
                          (relay)                (MCP server)

When Visual Studio is not running, the StdioProxy provides offline responses for basic protocol operations and returns cached tool definitions.

Multiple VS Instances

VS MCP Server supports multiple Visual Studio instances running simultaneously. Each VS instance registers itself via a port file (%LOCALAPPDATA%\VsMcp\server.<PID>.port) containing its HTTP port and the currently open solution path.

Instance Selection

StdioProxy selects which VS instance to connect to based on command-line arguments:

CWD-based Auto-Detection

When no --sln or --pid argument is provided, StdioProxy automatically discovers .sln files by walking up from the current working directory. This means that in most cases, no explicit configuration is needed — simply launching Claude Code from within a project directory is enough.

Configuration Examples

Single instance (auto-detect, no extra config needed):

claude mcp add vs-mcp -- "C:\Users\<USERNAME>\AppData\Local\VsMcp\bin\VsMcp.StdioProxy.exe"

Multiple instances (explicit solution-based — useful when CWD auto-detection is not sufficient):

{
  "mcpServers": {
    "vs-mcp-frontend": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe",
      "args": ["--sln", "C:\\Projects\\Frontend\\Frontend.sln"]
    },
    "vs-mcp-backend": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe",
      "args": ["--sln", "C:\\Projects\\Backend\\Backend.sln"]
    }
  }
}

Tool Filtering

Use the --tools argument to load only the tool categories you need. This reduces the number of tools exposed to the AI agent, which can improve token efficiency and response relevance.

Examples:

claude mcp add vs-mcp -- "C:\Users\<USERNAME>\AppData\Local\VsMcp\bin\VsMcp.StdioProxy.exe" --tools core,debug

{
  "mcpServers": {
    "vs-mcp": {
      "command": "C:\\Users\\<USERNAME>\\AppData\\Local\\VsMcp\\bin\\VsMcp.StdioProxy.exe",
      "args": ["--tools", "core,debug"]
    }
  }
}

You can also specify individual category names (e.g. --tools General,Build,Debugger). Omitting --tools loads all tools.

Reconnection

• If VS is restarted, StdioProxy automatically reconnects on the next tools/call request.
• Stale port files from crashed or closed VS instances are cleaned up automatically during discovery.

Contributing

Pull Requests are not accepted.

For feature requests and bug reports, please use GitHub Issues.

License

MIT License