Pylance MCP Pro

Professional Python Intelligence Server with REST API and AI Features

A production-ready Model Context Protocol (MCP) server that provides enhanced Pylance/Pyright language server capabilities with REST API access, AI-powered code analysis, and OpenTelemetry tracing.

🎯 What Makes This Different?

Unlike Microsoft's standard Pylance server, Pylance MCP Pro includes:

• ✅ REST API - HTTP endpoints for web/mobile integration
• ✅ AI Features - Claude-powered type error explanations (Pro tier)
• ✅ API Key Authentication - Secure access with tier-based rate limiting
• ✅ OpenTelemetry Tracing - Monitor performance and debug issues
• ✅ Conversation Logging - Track AI interactions for analysis
• ✅ Advanced Code Intelligence - Enhanced completions and diagnostics
• ✅ Professional Branding - Shows up distinctly in VS Code
• ✅ Custom Tools - 12 specialized Python analysis tools

🌐 Access Methods

1. MCP Protocol (Claude Desktop, Continue, Cursor)

Traditional MCP client integration via stdio.

2. REST API (Web/Mobile Apps)

HTTP endpoints for any application:

curl -X POST https://api.pylancemcp.com/api/v1/analyze \
  -H "X-API-Key: pmcp_your_key" \
  -H "Content-Type: application/json" \
  -d '{"file_path": "test.py", "content": "x: int = \"hello\""}'

See API_TESTING_GUIDE.md for full documentation.

🚀 Quick Installation

One-Line Install:

python install_to_vscode.py

Then reload VS Code (Ctrl+Shift+P → "Developer: Reload Window")

Manual Installation:

Add to your VS Code settings.json:

{
  "mcpServers": {
    "pylance-mcp-pro": {
      "command": "/path/to/.venv/Scripts/python.exe",
      "args": ["/path/to/server.py"],
      "env": {
        "WORKSPACE_ROOT": "${workspaceFolder}"
      },
      "enabled": true
    }
  },
  "chat.mcp.autostart": "always"
}

🔧 Finding Your Tools in VS Code

After installation and reload:

1. Open Copilot Chat (Ctrl+Alt+I)
2. Click the 🔧 tools icon in the chat input area
3. Look for "pylance-mcp-pro" (your custom server!)
4. You'll see all 12 tools listed

Note: This shows up separately from Microsoft's "pylance" server.

🛠️ Available Tools (12)

Code Intelligence:

• get_completions - Intelligent code completions with full type info
• get_hover - Type hints and documentation on hover
• get_definition - Go to definition across workspace
• get_references - Find all references to symbols

Code Quality:

• get_diagnostics - Errors, warnings, and type issues
• format_document - Professional code formatting
• rename_symbol - Safe refactoring across files

Navigation:

• get_signature_help - Function signatures and parameters
• get_document_symbols - File outline and structure
• get_workspace_symbols - Project-wide symbol search

Operations:

• apply_workspace_edit - Apply code changes safely
• health_check - Monitor server status

📊 Features

OpenTelemetry Tracing

Monitor your code intelligence operations in real-time with the AI Toolkit trace viewer.

Smart Environment Detection

Automatically detects and uses:

• Virtual environments (.venv, venv, env)
• Python version from your project
• Workspace-specific configurations

Professional Integration

• Seamless Copilot Chat integration
• Natural language queries
• Automatic tool selection
• Context-aware responses

💬 Usage Examples

Just ask naturally in Copilot Chat:

"What's the type of this variable?"
"Show me all references to calculate_total"
"Are there any type errors in this file?"
"Get completions for line 42, column 10"
"Format this document"

The appropriate tools are invoked automatically!

🔍 Verification

Check if it's running:

1. View → Output
2. Select "pylance-mcp-pro" from dropdown
3. Should show: "Discovered 12 tools"

Or run the test:

python server.py --test

🎓 For Users Installing Your Server

When someone installs this:

1. They run python install_to_vscode.py
2. Reload VS Code
3. Open Copilot Chat
4. Click 🔧 → See "pylance-mcp-pro" listed
5. Start asking Python questions!

The tools appear professionally in the Configure Tools menu!

🆚 vs Microsoft's Pylance

| Feature | Microsoft Pylance | Pylance MCP Pro | |---------|------------------|-----------------| | Basic Language Intelligence | ✅ | ✅ | | OpenTelemetry Tracing | ❌ | ✅ | | Conversation Logging | ❌ | ✅ | | Custom MCP Tools | ❌ | ✅ (12 tools) | | Shows in Configure Tools | Default | Distinct entry | | Professional Branding | Generic | Branded |

📝 Configuration

All settings in settings.json:

{
  "mcpServers": {
    "pylance-mcp-pro": {
      "command": "python.exe",
      "args": ["server.py"],
      "env": {
        "WORKSPACE_ROOT": "${workspaceFolder}"
      },
      "enabled": true
    }
  }
}

🐛 Troubleshooting

Tools not showing?

• Reload VS Code
• Check Output panel for "pylance-mcp-pro"
• Verify chat.mcp.autostart is "always"

Wrong server running?

• Look for "pylance-mcp-pro" not "pylance"
• Microsoft's is built-in, yours is custom

Need help?

• Run python server.py --test
• Check MCP_USAGE.md
• Review Output panel logs

🎉 Success!

When you see in Output:

Starting server pylance-mcp-pro
Discovered 12 tools

You're ready to go! 🚀

Your professional Python intelligence server is running and available in Copilot Chat's Configure Tools menu.