debugger-mcp

Debug Adapter Protocol (DAP) tools for Model Context Protocol (MCP).

Overview

debugger-mcp provides debugging capabilities through the Model Context Protocol, allowing AI assistants to:

• Launch and control debug sessions
• Set breakpoints and step through code
• Inspect variables and stack traces
• Track value changes over time
• Set and evaluate watch expressions
• Handle exception breakpoints
• Support source maps for TypeScript debugging
• Export debug logs for analysis

Installation

npm install debugger-mcp

Usage

As an MCP Server

npx debugger-mcp

Core Features

Session Management

• debugger_launch - Launch a new debug session
• debugger_attach - Attach to a running process
• debugger_disconnect - End debug session
• debugger_terminate - Forcefully terminate debug session
• debugger_list_sessions - List all active debug sessions

Breakpoints

• debugger_set_breakpoints - Set breakpoints in source files
• debugger_set_breakpoint - Set a single breakpoint
• debugger_remove_breakpoint - Remove a breakpoint
• debugger_list_breakpoints - List all breakpoints
• debugger_clear_breakpoints - Clear all breakpoints

Execution Control

• debugger_continue - Continue execution
• debugger_step_over - Step over to the next line
• debugger_step_into - Step into function calls
• debugger_step_out - Step out of current function
• debugger_pause - Pause execution

Debugging Tools

• debugger_get_stack_trace - Get current stack trace
• debugger_get_variables - Get variables in current scope
• debugger_evaluate - Evaluate expressions
• debugger_get_threads - Get thread information

Value Tracking

• debugger_track_value - Track value changes over time
• debugger_get_value_history - Get history of tracked values
• debugger_set_time_checkpoint - Set time checkpoints
• debugger_get_time_since_checkpoint - Get elapsed time since checkpoint

Exception Handling

• debugger_set_exception_breakpoints - Configure exception breakpoints
• debugger_get_exception_info - Get current exception information
• debugger_clear_exception_breakpoints - Clear exception breakpoints

Watch Expressions

• debugger_add_watch - Add a watch expression
• debugger_remove_watch - Remove a watch expression
• debugger_evaluate_watches - Evaluate all watch expressions
• debugger_list_watches - List all watch expressions

Source Map Support

• debugger_enable_source_maps - Enable/disable source map support
• debugger_check_source_map - Check if a file has source maps
• debugger_map_location - Map locations between source and generated code
• debugger_set_breakpoint_source_mapped - Set breakpoint with source map resolution

Logging and Export

• debugger_get_log - Get debug session log
• debugger_export_log - Export debug session logs
• debugger_get_events - Get debug events for a session

Supported Debug Adapters

• Node.js (built-in) - Full support for debugging Node.js applications
• Custom adapters can be added by implementing the Debug Adapter Protocol

Development

# Install dependencies
pnpm install

# Build
pnpm build

# Run tests
pnpm test

# Type check
pnpm typecheck

# Lint
pnpm lint

Architecture

The project is organized into several core modules:

• Session Management - Handles debug session lifecycle
• Breakpoint Management - Manages breakpoints across files
• Value Tracking - Tracks variable changes over time
• Watch Management - Manages watch expressions
• Source Map Support - Provides TypeScript debugging support
• Exception Handling - Manages exception breakpoints

Testing

The project includes comprehensive test coverage:

• Unit tests for all manager classes
• Integration tests for the complete debugging workflow
• Tests for exception handling, watch expressions, and source maps

License

MIT