Claude Desktop Setup

Prerequisites

Claude Desktop app installed
Pylance MCP Server running
Anthropic account with API access

Quick Start

Install Pylance MCP

Install via pip:

pip install pylance-mcp-server

Configure Claude

Edit Claude Desktop configuration:macOS: ~/Library/Application Support/Claude/claude_desktop_config.jsonWindows: %APPDATA%\Claude\claude_desktop_config.jsonLinux: ~/.config/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "pylance": {
      "command": "python",
      "args": ["-m", "pylance_mcp.server"],
      "env": {
        "PYLANCE_WORKSPACE": "/path/to/your/python/project"
      }
    }
  }
}

Restart Claude Desktop

Quit and reopen Claude Desktop app

Verify Setup

In Claude chat, type:

Can you analyze my Python workspace?

Claude should respond with workspace information.

Configuration Examples

Single Workspace

claude_desktop_config.json

{
  "mcpServers": {
    "pylance": {
      "command": "python",
      "args": ["-m", "pylance_mcp.server"],
      "env": {
        "PYLANCE_WORKSPACE": "/Users/you/projects/myapp",
        "PYTHONPATH": "/Users/you/projects/myapp"
      }
    }
  }
}

Multiple Workspaces

claude_desktop_config.json

{
  "mcpServers": {
    "pylance-backend": {
      "command": "python",
      "args": ["-m", "pylance_mcp.server", "--port", "3000"],
      "env": {
        "PYLANCE_WORKSPACE": "/Users/you/projects/backend"
      }
    },
    "pylance-ml": {
      "command": "python",
      "args": ["-m", "pylance_mcp.server", "--port", "3001"],
      "env": {
        "PYLANCE_WORKSPACE": "/Users/you/projects/ml-models"
      }
    }
  }
}

Cloud-Hosted

claude_desktop_config.json

{
  "mcpServers": {
    "pylance": {
      "url": "https://api.pylancemcp.dev",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY",
        "X-Workspace": "/path/to/workspace"
      }
    }
  }
}

Get your API key from pylancemcp.dev/dashboard

Usage Examples

Code Review

Ask Claude to review your code:

@pylance review the authentication module in src/auth.py

Claude will analyze:

Type safety issues
Potential bugs
Security vulnerabilities
Code style consistency
Best practice violations

Refactoring Assistance

Request refactoring help:

@pylance can you help refactor database.py to use async/await?

Claude will:

Analyze current implementation
Suggest refactoring approach
Generate refactored code
Explain changes made

Documentation Generation

Generate docstrings:

@pylance generate docstrings for all functions in utils.py

Output:

def calculate_total(items: List[Item]) -> float:
    """
    Calculate the total price of all items.
    
    Args:
        items: List of Item objects containing price information
        
    Returns:
        float: Sum of all item prices
        
    Raises:
        ValueError: If items list is empty
        
    Example:
        >>> items = [Item(price=10.0), Item(price=20.0)]
        >>> calculate_total(items)
        30.0
    """
    if not items:
        raise ValueError("Items list cannot be empty")
    return sum(item.price for item in items)

Test Generation

Generate unit tests:

@pylance create pytest tests for the User class in models/user.py

Claude generates comprehensive tests including:

Happy path scenarios
Edge cases
Error handling
Fixtures and mocks

Advanced Features

Context-Aware Conversations

Claude maintains context across messages:

You: @pylance what's the User model structure?
Claude: The User model has email, password_hash, created_at fields...

You: Add a last_login field to it
Claude: I'll add the last_login timestamp field to the User model...

Multi-File Analysis

Analyze dependencies across files:

@pylance trace how the login function works from API endpoint to database

Claude maps the flow:

api/auth.py:login_endpoint()
  → services/auth.py:authenticate_user()
    → models/user.py:User.verify_password()
      → database.py:query_user_by_email()

Intelligent Code Search

Search using natural language:

@pylance find all database queries that aren't using prepared statements

Claude locates potential SQL injection vulnerabilities.

Conversation Templates

Bug Investigation

@pylance I'm getting a TypeError on line 45 of main.py. 
The error message is: "unsupported operand type(s) for +: 'int' and 'str'"
Can you help debug this?

Feature Implementation

@pylance I need to add OAuth2 authentication to the API.
Can you:
1. Show me what files need to be modified
2. Generate the necessary code
3. Explain the security considerations

Performance Optimization

@pylance This function is slow with large datasets:
[paste code]
Can you suggest optimizations and show benchmarks?

Troubleshooting

MCP Server Not Found

Error: Command 'python' not foundFix: Use absolute path to Python:

{
  "command": "/usr/local/bin/python3",
  "args": ["-m", "pylance_mcp.server"]
}

Workspace Not Loading

Error: Failed to initialize workspaceChecklist:

✅ Workspace path exists
✅ Path has no trailing slash
✅ User has read permissions
✅ Contains Python files (.py)

Authentication Failed

Error: 401 UnauthorizedSolutions:

Check API key is valid
Verify subscription is active
Ensure API key has correct permissions

Claude Not Responding

Symptoms: No response to @pylance commandsDebug:

Check Claude Desktop logs:
- macOS: ~/Library/Logs/Claude/
- Windows: %APPDATA%\Claude\logs\
Verify MCP server is running:
ps aux | grep pylance_mcp
Test server manually:
python -m pylance_mcp.server --test

Performance Optimization

Large Workspaces

For projects with >5,000 files:

claude_desktop_config.json

{
  "mcpServers": {
    "pylance": {
      "command": "python",
      "args": [
        "-m", "pylance_mcp.server",
        "--max-workers", "4",
        "--cache-dir", "/tmp/pylance-cache"
      ],
      "env": {
        "PYLANCE_WORKSPACE": "/path/to/large/project",
        "PYLANCE_DIAGNOSTIC_MODE": "openFilesOnly"
      }
    }
  }
}

Memory Limits

Constrain memory usage:

{
  "env": {
    "PYLANCE_MAX_MEMORY": "2048",  // MB
    "PYLANCE_CACHE_SIZE": "500"     // MB
  }
}

Security Best Practices

Never commit claude_desktop_config.json with API keys to version control

Use environment variables:

claude_desktop_config.json

{
  "mcpServers": {
    "pylance": {
      "url": "https://api.pylancemcp.dev",
      "headers": {
        "Authorization": "Bearer ${PYLANCE_API_KEY}"
      }
    }
  }
}

Set in shell profile:

~/.zshrc

export PYLANCE_API_KEY="pk_live_..."

Tips & Tricks

Tip 1: Use @pylance at the start of messages for better context

Tip 2: Reference specific files: @pylance analyze src/models/user.py

Tip 3: Ask for alternatives: @pylance show 3 ways to implement this function

Tip 4: Request explanations: @pylance explain this decorator pattern

Next Steps

Continue.dev Setup

Configure for VS Code

Custom Workspace

Advanced workspace configuration

Get Started

Core Concepts

Guides

API Reference

Deployment

Prerequisites

Quick Start

Configuration Examples

Single Workspace

Multiple Workspaces

Cloud-Hosted

Usage Examples

Code Review

Refactoring Assistance

Documentation Generation

Test Generation

Advanced Features

Context-Aware Conversations

Multi-File Analysis

Intelligent Code Search

Conversation Templates

Bug Investigation

Feature Implementation

Performance Optimization

Troubleshooting

Performance Optimization

Large Workspaces

Memory Limits

Security Best Practices

Tips & Tricks

Next Steps

Continue.dev Setup

Custom Workspace

​Prerequisites

​Quick Start

​Configuration Examples

​Single Workspace

​Multiple Workspaces

​Cloud-Hosted

​Usage Examples

​Code Review

​Refactoring Assistance

​Documentation Generation

​Test Generation

​Advanced Features

​Context-Aware Conversations

​Multi-File Analysis

​Intelligent Code Search

​Conversation Templates

​Bug Investigation

​Feature Implementation

​Performance Optimization

​Troubleshooting

​Performance Optimization

​Large Workspaces

​Memory Limits

​Security Best Practices

​Tips & Tricks

​Next Steps

Continue.dev Setup

Custom Workspace

Prerequisites

Quick Start

Configuration Examples

Single Workspace

Multiple Workspaces

Cloud-Hosted

Usage Examples

Code Review

Refactoring Assistance

Documentation Generation

Test Generation

Advanced Features

Context-Aware Conversations

Multi-File Analysis

Intelligent Code Search

Conversation Templates

Bug Investigation

Feature Implementation

Performance Optimization

Troubleshooting

Performance Optimization

Large Workspaces

Memory Limits

Security Best Practices

Tips & Tricks

Next Steps