🧠 CodeArena 🚀

Your AI-First Platform for Coding, Collaboration & Career Growth

CodeArena is a cutting-edge, AI-powered ecosystem architected with a microservices-based MERN stack, combining Dockerized online judging, AI-integrated collaboration tools, and smart career utilities. With intelligent workflows powered by n8n and Relevance AI, CodeArena is more than a platform — it's your real-time coding and career companion.

🔍 Why CodeArena?

Unlike traditional coding platforms, CodeArena isn't just a judge or tracker — it's your interactive AI coding companion. Whether you’re preparing for coding contests, applying to internships, or looking for intelligent feedback on your code, CodeArena leverages the power of automation and LLMs to guide, evaluate, and elevate your journey in tech.

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🎥 Demo Video

Watch CodeArena in action! Demo Video

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🌐 Deployed Links

• Frontend: https://contest-onlinejudge.vercel.app
• Backend API: https://codearena-1f1w.onrender.com
• Chrome Extension (Internship Tracker): Available on [Chrome Web Store]

📚 Table of Contents

• 📌 Overview

• ✨ Key Features

  • 🔁 Real-Time Contest Tracking
  • 💻 Online Compiler & Judge (with Docker)
  • 🤖 AI Agents (Built with n8n + Relevance AI)
  • 🤝 Real-Time Collaborative Rooms
  • 🧳 Internship Tracker + Chrome Extension
  • 🛠️ Admin Dashboard

• 🎨 UI Snapshots

• 🔬 Architecture Overview

• 🧠 How AI is Used

• ⚙️ Tech Stack

• 🚀 Installation Guide

• 📜 License

• 📬 Contact

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📌 Overview

CodeArena is a modern, AI-powered web application that combines three major tools into one cohesive system:

1. Real-time contest tracking
2. Built-in code submission and judging
3. Internship tracking with smart follow-ups

This platform uses n8n-based AI agents and Relevance AI for generating problem hints, evaluating user code, and tracking internships — making it a complete ecosystem for growth in tech.

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✨ Key Features

🔁 Real-Time Contest Tracking

• Aggregates live and upcoming contests from Codeforces, CodeChef, LeetCode, and more.
• Displays contest calendar with user-specific filters.
• Compares past performance across platforms.

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💻 Online Compiler & Judge (with Docker)

• Secure multi-language code compiler for C++, Java, Python, JavaScript, and more.
• Submissions run inside isolated Docker containers for maximum safety.
• Verdict system supports custom inputs, standard test cases, and AI-generated edge cases.

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🤝 Real-Time Collaborative Rooms

• Interactive Peer Rooms for collaborative coding and learning
• Shared live document editor for notes and problem statements
• Synchronized code editor to write and debug code together
• Integrated chatbox with voice assistance for seamless communication
• Ideal for pair programming, study groups, and real-time contest collaboration

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🤖 AI Agents (Built with n8n + Relevance AI)

⚡ Powering automation, hints, insights, and reminders

• n8n Workflows automate:

  • Contest reminders
  • Internship follow-up nudges
  • Hint generation triggers

• Relevance AI Integration:

  • Code analysis: readability, complexity, optimization tips
  • Personalized hint generation for each problem
  • Semantic code similarity analysis for plagiarism checks

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🧳 Internship Tracker + Chrome Extension

• Track applied internships, deadlines, company names, and current status.
• AI agents schedule follow-ups and remind you about interviews.
• A custom Chrome Extension lets users auto-save internship listings from job portals like LinkedIn, Internshala, etc.

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🛠️ Admin Dashboard

• Add, edit, and manage coding questions.
• Auto-generate test cases using Relevance AI.
• Review user submissions and performance insights.
• Manage contests, problems, and announcements.

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🎨 UI Snapshots

(Screenshots Coming Soon) The platform features a clean, fast, responsive interface built with TailwindCSS, providing an intuitive experience on both desktop and mobile.

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🔬 Architecture Overview

User ↔ Frontend (React + Tailwind) ↔ Backend (Express + Node)
       ↘                            ↙
      AI Agent Engine (n8n + Relevance AI)
           ↘         ↙
     MongoDB         Dockerized Judge Engine

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🧠 How AI is Used

AI Feature	Powered By	Description
🧠 Code Hint Generation	Relevance AI + n8n	Generates contextual hints per problem and code state
🔍 Code Feedback & Analysis	Gemini AI	Reviews code for quality, performance, and best practices
🧪 Test Case Generation	n8n + Open AI models	Creates comprehensive and edge case test sets
📆 Internship Reminders	n8n + chrome extension	Sends alerts based on deadlines, stages, and follow-ups
🤖 Chat-based Interview Prep	Relevance AI	Suggests questions & tips based on internship data
⚠️ Plagiarism Detection	Relevance AI + Semantic AI	Compares solutions semantically across users

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⚙️ Tech Stack

Layer	Tech
Frontend	React.js, TailwindCSS
Backend	Node.js, Express.js
Database	MongoDB
Compiler	Docker, Custom Judge API, Monacco Editor
Automation	n8n (Self-hosted or cloud)
AI Platform	Relevance AI
Extensions	Chrome Extension (Manifest V3)

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Demo Video

mydemo.1.mp4

🚀 Installation Guide

1. Clone the Repository

git clone https://github.com/kanikaa-3018/contest_onlinejudge.git
cd contest_onlinejudge

2. Set Up Environment Variables

Create a .env file in both /server and /client:

# server/.env
PORT=8080
MONGO_URI=your_mongodb_uri
JWT_SECRET=your_jwt_secret
GEMINI_API_KEY=your_openai_key
RELEVANCE_AI_KEY=your_relevance_ai_key
BACKEND_URL=your_backend_url
COMPILER_BACKEND_URL=your_compilerserver_url

#client/.env
CF_API_KEY=your_codeforces_api_key
CF_SECRET=your_codeforces_secret
VITE_RELEVANCE_AI_KEY=your_relevance_ai_key
VITE_BACKEND_URL=your_backend_url

3. Install Backend & Frontend Dependencies

cd server
npm install
npm run dev

In another terminal:

cd client
npm install
npm run dev

In another terminal:

cd compiler-server
npm install
npm run dev

4. (Recommended) Run with Docker

Make sure Docker is installed and running:

docker-compose up --build

This will spin up the entire backend, including the secure judge engine in containers.

5. Set Up Chrome Extension (Internship Tracker)

The Chrome Extension helps you auto-save internship listings from job portals like LinkedIn, Internshala, etc.

To install it locally:

1. Open Chrome and go to chrome://extensions/.
2. Enable Developer Mode (top right).
3. Click "Load unpacked".
4. Navigate to and select the /chrome-extension folder in your cloned repo.
5. The extension will now be available in your browser.
6. Open any internship/job portal and use the extension to save listings directly into your Internship Tracker dashboard.

Make sure the backend server is running so the extension can post data properly.

6. n8n Setup (AI Agents & Automation)

You can self-host or use n8n Cloud to power AI automation workflows for:

🧠 Hint generation

🧳 Internship follow-ups

📊 Daily Progress summary generator

📅 RealTime chatbot for queries using Relevance AI

🔁 📥 View and Download n8n Workflow JSON

You can directly download and import the following n8n workflows into your own workspace.

⚠️ Note: Make sure to update the Webhook Trigger node in each workflow with the correct URL from your own n8n instance. Webhook URLs are unique per workspace.

• Download n8n Hint Generator JSON (Generates AI hints and feedback on user code submissions)

• Download n8n Internship Tracker JSON (Tracks internships and sends follow-up reminders via AI agent)

• Download n8n Report Analyzer JSON (Summarizes contest performance, weaknesses, and submits AI reports)

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📜 License

This project is licensed under the MIT License. Feel free to fork, enhance, and contribute to the project!

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📬 Contact

Kanika Singhal 🚀 Full Stack Developer | AI Explorer 🌐 GitHub: kanikasinghal 📧 Email: kanikasin216@gmail.com