Visual Studio MCP Bridge

A Model Context Protocol (MCP) server that connects AI coding assistants (like Claude) to Visual Studio 2022/2026 via COM automation.

This bridge enables AI agents to:

📖 Read build output, debug logs, and error lists
🔨 Build solutions and check for errors
🐛 Start/stop debugging sessions
📍 Inspect call stacks at breakpoints

Perfect for autonomous AI-driven development workflows where the agent can build, test, and debug without human intervention.

🚀 Quick Start

Prerequisites

Windows 10/11
.NET 8.0 SDK or higher
Visual Studio 2022 or 2026 (must be running)
Claude Desktop or another MCP-compatible client

Installation

Clone and build:

git clone https://github.com/YOUR_USERNAME/vs-mcp-bridge.git
cd vs-mcp-bridge
dotnet publish -c Release -f net8.0 -r win-x64 --self-contained false

Register with Claude:

claude mcp add vs-bridge -- "<full-path>\bin\Release\net8.0\win-x64\publish\VisualStudioMcpServer.exe"

Open Visual Studio with any solution, then start using the tools!

🛠️ Available Tools

Information Tools

| Tool | Description | |------|-------------| | GetSolutionInfo | Returns current solution path and list of projects | | ListOutputPanes | Lists all Output Window panes (Build, Debug, etc.) | | ReadOutputPane | Reads content from a specific pane (with truncation) | | GetErrorList | Returns all errors and warnings from the Error List |

Build & Debug Tools

| Tool | Description | |------|-------------| | BuildSolution | Builds the solution and returns success/error count | | StartDebugging | Starts debugging (F5) | | StartWithoutDebugging | Runs without debugger (Ctrl+F5) | | StopDebugging | Stops the current debug session | | GetDebuggerState | Returns current state (design/running/breakpoint) | | GetCallStack | Returns call stack when stopped at a breakpoint |

🤖 Autonomous Testing Workflow

Claude can now run this autonomous development loop:

1. BuildSolution → Check for compile errors
2. If errors: GetErrorList → Analyze and fix code → Rebuild
3. If success: StartDebugging
4. GetDebuggerState → Monitor execution
5. If at breakpoint: GetCallStack → Analyze the issue
6. StopDebugging → Make fixes → Repeat

⚙️ Technical Details

COM Message Filter

Visual Studio is a single-threaded COM server. When VS is busy (building, debugging), it rejects COM calls. This bridge implements IOleMessageFilter to automatically retry rejected calls.

.NET Core Compatibility

Since Marshal.GetActiveObject was removed in .NET Core, this project uses P/Invoke to oleaut32.dll and ole32.dll for COM object retrieval.

STAThread Requirement

COM automation requires a Single-Threaded Apartment (STA). The main thread is marked with [STAThread] to ensure proper COM interop.

📋 Tool Parameters

ReadOutputPane

paneName: string   - Name (or partial name) of the pane to read
maxLines: int      - Max lines to return from end (default: 50, 0 = all)

BuildSolution

waitForBuild: bool - Wait for completion (default: true)
format: string     - Output format: "text" or "json"

GetErrorList / GetSolutionInfo / GetDebuggerState / GetCallStack

format: string     - Output format: "text" or "json"

🔧 Troubleshooting

| Issue | Solution | |-------|----------| | "No VS instance found" | Ensure Visual Studio is running with a solution open | | Tools not appearing | Restart Claude after re-registering the MCP | | COM errors | Make sure VS isn't in a modal dialog (e.g., unsaved changes prompt) |

📄 License

MIT License - see LICENSE for details.

🤝 Contributing

Contributions welcome! Feel free to open issues or PRs.

Ideas for future tools:

SetBreakpoint - Add/remove breakpoints programmatically
EvaluateExpression - Evaluate expressions in debugger context
OpenFile - Open specific files in VS editor
NavigateToError - Jump to error location

MCP Servers