MapCoder Plugin for Claude Code

A multi-agent code generation plugin that replicates the human programming cycle through four specialized agents: Retrieval, Planning, Coding, and Debugging. Port of MapCoder: Multi-Agent Code Generation for Competitive Problem Solving

Overview

• 🐱 Code • 📃 Paper • 🌐 Website

MapCoder implements a systematic approach to solving coding problems:

Quick Start

Installation

/plugin marketplace add NewJerseyStyle/Claude-plugins-marketplace
/plugin install mapcoder@code-agent-ports

Basic Usage

# Solve a coding problem (defaults to Python)
/mapcoder implement binary search

# Specify a language
/mapcoder --lang javascript implement a debounce function

# Use sandbox for safer execution
/mapcoder --sandbox implement file operations

# Read problem from file
/mapcoder problem.txt

Available Skills

Skill	Description
/mapcoder	Full pipeline: retrieve → plan → code → debug
/mapcoder-retrieve	Generate similar problems from knowledge
/mapcoder-plan	Create algorithmic plans
/mapcoder-code	Implement code from plans
/mapcoder-debug	Fix failing code

Language Support

Default language is Python. Supported languages:

Language	Flag	Example
Python	--lang python	/mapcoder --lang python two sum
JavaScript	--lang javascript	/mapcoder --lang javascript two sum
TypeScript	--lang typescript	/mapcoder --lang typescript two sum
Rust	--lang rust	/mapcoder --lang rust two sum
Go	--lang go	/mapcoder --lang go two sum
Java	--lang java	/mapcoder --lang java two sum
C++	--lang cpp	/mapcoder --lang cpp two sum

RAG Integration (Optional)

MapCoder can integrate with external knowledge bases for enhanced retrieval for best performance. Two options are supported:

Option A: crawl4ai-rag (Full-featured)

Best for teams with existing infrastructure who want powerful web crawling and RAG capabilities.

Requirements:

• Docker
• Supabase with pgvector extension
• OpenAI API key

Setup:

1. Follow the setup guide at: https://github.com/coleam00/mcp-crawl4ai-rag
2. Start the MCP server: docker-compose up -d
3. Edit .mcp.json in this plugin and set "disabled": false for crawl4ai-rag

Option B: mcp-rag-server (Lightweight)

Best for local development with minimal setup.

Setup:

1. Install nodejs: Tutorial
2. Install RAG server by terminal command: npm install -g mcp-rag-server (Follow the setup guide at: https://github.com/kwanLeeFrmVi/mcp-rag-server#installation)
3. Edit .mcp.json in this plugin and set "disabled": false for rag-server

Sandbox Execution (Recommended)

For safer code execution, especially when working with file operations or untrusted problems, use the sandbox feature.

Setup

1. Install Docker: https://docs.docker.com/get-docker/

2. Build the sandbox image:

   cd mapcoder-plugin
   docker build -t mapcoder-sandbox -f Dockerfile.sandbox .

3. Verify it works:

   ./scripts/sandbox-runner.sh python -c "print('Hello, Sandbox!')"

Usage

Add --sandbox flag to any /mapcoder command:

/mapcoder --sandbox implement file deletion utility

Configuration

Environment variables for sandbox:

Variable	Default	Description
MAPCODER_SANDBOX_IMAGE	mapcoder-sandbox	Docker image name
MAPCODER_TIMEOUT	30	Execution timeout (seconds)
MAPCODER_MEMORY	256m	Memory limit
MAPCODER_CPU	1	CPU limit

Safety Warnings

Direct Execution (Default)

When running without --sandbox, code executes directly on your system.

Recommendations:

• Back up important files before running
• Review generated code before allowing execution
• Do not use on production systems
• Avoid problems involving file system operations without sandbox

Code Review

The plugin validates syntax before execution but cannot guarantee code safety. Always review:

• File operations (read, write, delete)
• Network operations
• System commands
• Any code that modifies state

Configuration

Plugin Configuration

Edit .claude-plugin/plugin.json to customize:

{
  "name": "mapcoder",
  "version": "1.0.0",
  "skills": "./skills/",
  "agents": "./agents/",
  "hooks": "./hooks/hooks.json",
  "mcpServers": "./.mcp.json"
}

Hook Configuration

Edit hooks/hooks.json to customize validation:

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Write|Edit",
        "hooks": [
          {
            "type": "command",
            "command": "python scripts/validate-code.py \"$TOOL_INPUT_FILE_PATH\""
          }
        ]
      }
    ]
  }
}

Troubleshooting

Plugin not loading

# Check plugin structure
ls -la .claude-plugin/
# Should show plugin.json

# Verify JSON is valid
python -c "import json; json.load(open('.claude-plugin/plugin.json'))"

Sandbox not working

# Check Docker is running
docker info

# Check image exists
docker images | grep mapcoder-sandbox

# Rebuild if needed
docker build -t mapcoder-sandbox -f Dockerfile.sandbox .

Tests timing out

Increase timeout:

export MAPCODER_TIMEOUT=60
/mapcoder --sandbox "solve complex problem"

License

MIT License - See LICENSE file for details.

Acknowledgments

Based on the MapCoder paper: "MapCoder: Multi-Agent Code Generation for Competitive Problem Solving"

@article{islam2024mapcoder,
  title={MapCoder: Multi-Agent Code Generation for Competitive Problem Solving},
  author={Islam, Md Ashraful and Ali, Mohammed Eunus and Parvez, Md Rizwan},
  journal={arXiv preprint arXiv:2405.11403},
  year={2024}
}