agentic-debugger

An MCP (Model Context Protocol) server that enables interactive debugging with code instrumentation for AI coding assistants. Inspired by Cursor's debug mode.

Works with any MCP-compatible AI coding tool:

Claude Code
Cursor
Windsurf
Cline
GitHub Copilot
Kiro
Zed
And more...

Features

Live code instrumentation - Inject debug logging at specific lines
Variable capture - Log variable values at runtime
Multi-language support - JavaScript, TypeScript, and Python
Browser support - CORS-enabled for browser JS debugging
Clean removal - Region markers ensure instruments are fully removed

Installation

Using npx (recommended)

Add to your MCP configuration:

{ "mcpServers": { "debug": { "command": "npx", "args": ["-y", "agentic-debugger"] } } }

Configuration file locations:

Claude Code: ~/.mcp.json
Cursor: .cursor/mcp.json in your project or ~/.cursor/mcp.json
Other tools: Check your tool's MCP documentation

Global install

npm install -g agentic-debugger

Then configure:

{ "mcpServers": { "debug": { "command": "agentic-debugger" } } }

Available Tools

Tool	Description
`start_debug_session`	Start HTTP server for log collection
`stop_debug_session`	Stop server and cleanup
`add_instrument`	Insert logging code at file:line
`remove_instruments`	Remove debug code from file(s)
`list_instruments`	Show all active instruments
`read_debug_logs`	Read captured log data
`clear_debug_logs`	Clear the log file

How It Works

Start session - Spawns a local HTTP server (default port 9876)
Add instruments - Injects fetch() calls that POST to the server
Reproduce bug - Run your code, instruments capture variable values
Analyze logs - Read the captured data to identify issues
Cleanup - Remove all instruments and stop the server

Debug Workflow Example

You: "Help me debug why the total is NaN" AI Assistant: 1. Starts debug session 2. Reads your code to understand the logic 3. Adds instruments at suspicious locations 4. "Please run your code to reproduce the issue" You: *runs code* "Done" AI Assistant: 5. Reads debug logs 6. "I see `discount` is undefined at line 15..." 7. Removes instruments 8. Fixes the bug 9. Stops debug session

Instrument Examples

JavaScript/TypeScript

// #region agentic-debug-abc123 fetch('http://localhost:9876/log', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ id: 'abc123', location: 'cart.js:15', timestamp: Date.now(), data: { total, discount, items } }) }).catch(() => {}); // #endregion agentic-debug-abc123

Python

# region agentic-debug-abc123 try: import urllib.request as __req, json as __json __req.urlopen(__req.Request( 'http://localhost:9876/log', data=__json.dumps({ 'id': 'abc123', 'location': 'cart.py:15', 'timestamp': __import__('time').time(), 'data': {'total': total, 'discount': discount} }).encode(), headers={'Content-Type': 'application/json'} )) except: pass # endregion agentic-debug-abc123

Supported Languages

Language	Extensions
JavaScript	`.js` , `.mjs` , `.cjs`
TypeScript	`.ts` , `.tsx`
Python	`.py`

Requirements

Node.js >= 18.0.0
An MCP-compatible AI coding assistant

License

MIT

One-click Deploy

A

security – no known vulnerabilities

A

license - permissive license

A

quality - confirmed to work

How are these scores calculated?

Resources

GitHub Repository

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Related Servers

agentic-debugger

agentic-debugger

Features

Installation

Using npx (recommended)

Global install

Available Tools

How It Works

Debug Workflow Example

Instrument Examples

JavaScript/TypeScript

Python

Supported Languages

Requirements

License

Resources

Tools

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