🚀 CodePilot AI

Open-source, AI-powered coding interview preparation platform with algorithm practice, interactive syntax training, and guided coaching.

✨ Features • 🏁 Quick Start • 🏗️ Architecture • 🛠️ Tech Stack • 🤝 Contributing

Developed by Anvar Baltakhojayev

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✨ Features

🧩 100 Curated Problems — Challenges from Easy to Hard across 21 topic categories including arrays, trees, graphs, dynamic programming, backtracking, and more.

🌐 9 Programming Languages — Write and execute code in Python, JavaScript, TypeScript, Java, C++, C, Go, Rust, and C#.

📚 Interactive Syntax Trainer — 13 curriculum categories with ~500 hands-on exercises across all 9 languages. Learn data structure patterns and language syntax through guided practice with instant feedback.

📝 Monaco Editor — The same editor powering VS Code, with syntax highlighting, bracket colorization, and font ligatures.

⚡ Code Execution — Run your code against visible and hidden test cases via Judge0, with real-time execution time and memory stats.

💡 AI-Guided Hints — Three modes to match your practice style:

Mode	Style	Description
🔒 Strict	No hints	Pure interview simulation
🎓 Interviewer	Socratic	Guiding questions that nudge without revealing
📖 Learning	Direct	Pseudocode, partial snippets, and explanations

Each mode supports 5 progressive hint levels — from a subtle nudge to a detailed walkthrough.

🔍 AI Code Review — After running your code, get a senior-engineer-level debrief with overall feedback, time and space complexity analysis, edge cases to consider, and actionable improvements.

🤖 AI Mentor Chat — Context-aware AI assistant with two personalities: coaching mode for problems (no spoilers) and tutoring mode for syntax (teaches freely with code examples).

💾 Auto-Save — Your code is automatically saved to browser localStorage. Pick up right where you left off.

🎨 Modern Landing Page — Interactive homepage with animated hero, live code demo, mouse-parallax effects, and scroll-reveal animations.

📌 Formerly known as "AI Interview Coach" — rebranded to CodePilot AI.

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🏁 Quick Start

1️⃣ Environment Setup

cp .env.example .env.local

Edit .env.local and fill in your keys:

Variable	Required	Description
OPENAI_API_KEY	✅	OpenAI or compatible provider API key
OPENAI_BASE_URL	❌	Default: https://api.openai.com/v1
OPENAI_MODEL	❌	Default: gpt-4.1-mini
JUDGE0_URL	✅	Judge0 instance URL
X_RAPIDAPI_KEY	✅*	Required for RapidAPI-hosted Judge0

2️⃣ Start the Backend

cd server
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
uvicorn main:app --reload --port 8000

3️⃣ Start the Frontend

npm install
npm run dev

Open 👉 http://localhost:3000

4️⃣ (Optional) Start Infrastructure

docker compose up -d

🐳 Starts Postgres & Redis — scaffolded for future features, not required for the current MVP.

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🏗️ Architecture

┌──────────────────────────────────────────────────────────────────┐
│                    Browser (localhost:3000)                        │
│                                                                    │
│  / ................ Landing page (overview, live demo, features)  │
│  /practice ........ Problem solving + Syntax trainer workspace   │
│  /contact ......... Contact page                                  │
│                                                                    │
│  ┌─ Practice: Problems View ──────────────────────────────────┐  │
│  │ 100 problems | Difficulty & topic filters | Search          │  │
│  └─────────────────────────────────────────────────────────────┘  │
│  ┌─ Practice: Workspace ──────────────────────────────────────┐  │
│  │ Problem Panel │ Monaco Editor │ Tests|Hint|Review|AI tabs   │  │
│  └─────────────────────────────────────────────────────────────┘  │
│  ┌─ Practice: Syntax Trainer ─────────────────────────────────┐  │
│  │ Learn|Reference │ 9 Languages │ 13 categories │ AI Chat     │  │
│  └─────────────────────────────────────────────────────────────┘  │
│                                                                    │
│  localStorage ◄── Auto-save code attempts (debounced 1s) ──►    │
└────────────────────────────┬───────────────────────────────────────┘
                             │
          POST /api/execute, /api/hint, /api/review,
          /api/syntax/explain, /api/syntax/check
          (Next.js API routes → FastAPI)
                             │
                             ▼
┌──────────────────────────────────────────────────────────────────┐
│                  FastAPI Backend (localhost:8000)                  │
│                                                                    │
│  ⚡ POST /execute       ──► Judge0 (code execution, 9 languages) │
│  💡 POST /hint          ──► OpenAI-compatible LLM                 │
│  🔍 POST /review        ──► OpenAI-compatible LLM                 │
│  📖 POST /syntax/explain ──► LLM (syntax explain / translate)    │
│  ✅ POST /syntax/check   ──► Judge0 + pattern checks + LLM       │
└──────────────────────────────────────────────────────────────────┘

📁 Project Structure

codepilot-ai/
├── 🌐 app/                          Next.js App Router
│   ├── layout.tsx                    Root layout (Inter font, dark theme)
│   ├── page.tsx                      Landing / homepage
│   ├── practice/page.tsx             Practice workspace (Problems + Syntax)
│   ├── contact/page.tsx              Contact page
│   ├── globals.css                   Global styles + animations
│   └── api/                          API proxy routes → FastAPI
│       ├── execute/route.ts
│       ├── hint/route.ts
│       ├── review/route.ts
│       └── syntax/
│           ├── explain/route.ts
│           └── check/route.ts
├── 🧱 components/                    React UI components
│   ├── AIChatPanel.tsx               AI chat (dual mode: syntax/problem)
│   ├── CodeEditor.tsx                Monaco editor + language picker
│   ├── ProblemPanel.tsx              Problem description & examples
│   ├── ProblemsView.tsx              Problem browser with filters
│   ├── RightPanel.tsx                Tabbed panel (Tests/Hint/Review/AI)
│   ├── TestResults.tsx               Execution results display
│   ├── HintPanel.tsx                 Hint controls & display
│   ├── ReviewPanel.tsx               AI review display
│   └── syntax/                       Syntax Trainer components
│       ├── SyntaxPanel.tsx           Main panel (Learn/Reference, language)
│       ├── LessonTrainer.tsx         Interactive trainer with progress
│       ├── TrainerSection.tsx        Exercise: explain → example → try → check
│       ├── ExerciseEditor.tsx        Monaco editor for exercises
│       ├── FeedbackPanel.tsx         Exercise result + AI feedback
│       ├── LessonView.tsx            Static reference lesson view
│       ├── LessonList.tsx            Reference lesson grid
│       └── SyntaxSnippet.tsx         Code snippet with copy button
├── 📚 data/
│   ├── problems/                     100 problem JSON definitions
│   └── syntax/
│       ├── lessons/                  4 static reference lessons
│       └── trainer/                  117 interactive trainer lessons
│           └── curriculum.json       13 category definitions
├── 🔧 lib/                          Shared frontend utilities
│   ├── types.ts                      TypeScript type definitions
│   ├── problems.ts                   Problem loader (100 problems)
│   ├── trainer.ts                    Trainer lesson loader (117 lessons)
│   ├── syntax.ts                     Reference lesson loader
│   └── storage.ts                    localStorage helpers
├── 🐍 server/                        Python FastAPI backend
│   ├── main.py                       App entry point, 7 endpoints
│   ├── requirements.txt
│   ├── models/schemas.py             Pydantic request/response models
│   └── services/
│       ├── judge0.py                 Judge0 integration (9 languages)
│       ├── llm.py                    LLM client (hints, review, syntax)
│       └── prompts.py                Prompt templates
├── 🖼️ public/                        Static assets
│   └── favicon.svg                   App favicon
└── 🐳 docker-compose.yml             Postgres + Redis (scaffolded)

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🗺️ Pages & Routes

Route	Page	Description
/	🏠 Home	Landing page with hero, feature grid, live code demo, how it works, open source section
/practice	💻 Practice	Full workspace: Problems list, Syntax trainer, coding workspace with AI tools
/contact	📬 Contact	Contact cards for email, LinkedIn, and GitHub

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📡 API Endpoints

Method	Path	Description
POST	/execute	⚡ Run code against test cases via Judge0
POST	/hint	💡 Generate AI hint (5 levels, 3 modes)
POST	/review	🔍 Generate AI code review (structured JSON)
POST	/syntax/explain	📖 AI syntax explanation with dual mode
POST	/syntax/check	✅ Exercise validation: Judge0 + pattern checks + AI feedback
GET	/health	🏥 Health check
GET	/problems	📋 List all 100 problems
GET	/problems/{id}	🔎 Single problem details

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🔄 Using with Claude or Other Providers

The backend works with any OpenAI-compatible API. Update your .env.local:

# 🤖 Anthropic Claude
OPENAI_BASE_URL=https://api.anthropic.com/v1
OPENAI_API_KEY=sk-ant-...
OPENAI_MODEL=claude-sonnet-4-20250514

# 🏠 Local model (Ollama, LM Studio, vLLM)
OPENAI_BASE_URL=http://localhost:11434/v1
OPENAI_API_KEY=not-needed
OPENAI_MODEL=llama3

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🛠️ Tech Stack

Layer	Technology
🌐 Frontend	Next.js 14, React 18, TypeScript, Tailwind CSS, Monaco Editor
🐍 Backend	Python FastAPI, Pydantic, Uvicorn
⚡ Execution	Judge0 CE (9 languages)
🤖 AI	OpenAI-compatible chat API (GPT, Claude, Llama, etc.)
💾 Storage	Browser localStorage
🐳 Infra	Docker Compose (Postgres + Redis scaffolded)

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🤝 Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

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📄 License

MIT

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⚡ CodePilot AI — Built with ❤️ by Anvar Baltakhojayev