Node Debugger

What is Node Debugger?

Node Debugger is an MCP server that provides Node.js debugging capabilities with process management for AI agents. It integrates with the Node.js Inspector API, allowing agents to start, stop, and debug Node.js processes using full Chrome DevTools Protocol.

How to use Node Debugger?

Install by running npm install and npm run build, then configure the server with Claude Code via the .mcp.json file or by adding it to global configuration using claude mcp add. Once configured, agents can use tools like start_node_process, attach_debugger, set_breakpoint, step_debug, and evaluate_expression.

Key features of Node Debugger

• Start/stop Node.js processes with debugging enabled
• Set breakpoints with optional conditions and step through code
• Connect to the Node.js Inspector API for real debugging
• Designed for long-running, AI-agent-driven debugging sessions
• Automatically pauses on start using --inspect-brk flag
• Tracks and manages multiple concurrent debugging sessions

Use cases of Node Debugger

• AI agent debugging a Node.js application by setting breakpoints and stepping through code
• Automated testing workflows that require process lifecycle management
• Interactive debugging sessions where an agent evaluates expressions in a live context

FAQ from Node Debugger

How do I set breakpoints reliably?

Use full file:// URLs when specifying the file path in the set_breakpoint tool, for example file:///Users/you/project/script.js.

How does automatic pausing work?

The server launches Node.js scripts with the --inspect-brk flag, which pauses execution at the first line, allowing the debugger to connect before any code runs.

What protocol does Node Debugger use?

It uses the full Chrome DevTools Protocol, providing real debugging (not simulation) through the Node.js Inspector API.

Does Node Debugger require any special runtime?

It requires a Node.js environment to build and run the server itself. The managed processes also need Node.js to execute.

How can I see all managed processes?

Use the list_processes tool to show all processes managed by the server, or access the debug://processes resource.