LeetCode Practice Tracker

A TypeScript console application that collects LeetCode questions and stores them in PostgreSQL or Notion databases. Specializes in fetching LeetCode questions, Google-specific questions, and Grind75 questions.

Features

• 🔍 Fetch questions from LeetCode's GraphQL API
• 🏢 Get company-specific questions (requires authentication)
• 📚 Scrape Grind75 questions from techinterviewhandbook.org
• 💾 Store data in PostgreSQL or Notion databases
• 📊 Structured logging with file rotation
• 🔧 Robust error handling and retry mechanisms
• ⚡ TypeScript with strict mode for type safety

Prerequisites

• Node.js v18 or higher
• npm

Installation

# Clone the repository
git clone <repository-url>
cd leetcode-practice-tracker

# Install dependencies
npm install

Usage

# Build and run the application
npm start

# Or manually build and run
npx tsc && node --es-module-specifier-resolution=node build/index.js

The application will present an interactive menu to:

• Choose question sources (LeetCode, Grind75, company-specific)
• Select storage destination (PostgreSQL, Notion)
• Configure fetching options

Configuration

Create a .env file in the root directory:

# Optional: Set log level (default: info)
LOG_LEVEL=debug

# For LeetCode session (required for company-specific questions)
LEETCODE_SESSION_ID=your_session_cookie

# For LeetCode CSRF token (REQUIRED for Premium accounts, optional for free accounts)
LEETCODE_CSRF_TOKEN=your_csrf_token

# For Notion integration
NOTION_TOKEN=your_notion_integration_token

# For PostgreSQL
DATABASE_URL=postgresql://username:password@localhost:5432/dbname

Authentication

LeetCode Session (Required for Premium Users)

For full functionality, especially with Premium accounts, you need both your LeetCode session cookie and CSRF token:

1. Log into LeetCode in your browser
2. Open Developer Tools (F12 or right-click → Inspect)
3. Go to the Application tab (Chrome) or Storage tab (Firefox)
4. Navigate to Cookies → https://leetcode.com
5. Find and copy the LEETCODE_SESSION value
6. Find and copy the csrftoken value
7. Add both to your .env file:

   LEETCODE_SESSION_ID=your_session_value_here
   LEETCODE_CSRF_TOKEN=your_csrf_token_value_here

Note for Premium Users: The CSRF token is required for Premium accounts to authenticate properly with LeetCode's GraphQL API. Without it, you may experience authentication failures even with a valid session ID.

Notion Integration

1. Create a Notion integration at https://www.notion.so/my-integrations
2. Copy the integration token
3. Add it to your .env file

Architecture

Core Components

• Entry Point (src/index.ts): CLI interface and main application loop
• User Interface (src/core/inquirer.ts): Interactive prompts using inquirer.js
• Terminal Controller (src/core/terminal.ts): Main business logic orchestration

Services

• LeetCode (src/core/leetcode.ts): GraphQL API integration
• Grind (src/core/grind.ts): Web scraping with Puppeteer
• Database (src/core/database.ts): PostgreSQL with Sequelize ORM
• Notion (src/core/notion.ts): Notion API integration

Project Structure

src/
├── @types/         # Custom type definitions
├── core/           # Main business logic classes
├── query/          # GraphQL queries and database schemas
├── types/          # TypeScript type definitions
├── utils/          # Helper utilities and logging
└── index.ts        # Application entry point

build/              # Compiled JavaScript (gitignored)
logs/               # Application logs with rotation

Logging

The application uses structured logging with daily rotation:

• Logs are written to the logs/ directory
• Separate files by level: info-YYYY-MM-DD.log, error-YYYY-MM-DD.log
• Set LOG_LEVEL=debug in .env for verbose console output
• Automatic log rotation (10MB max, 5 files retained)
• Sensitive data is automatically sanitized from logs

Error Handling

• Centralized error handling with custom error types
• Retry mechanisms with exponential backoff for API calls
• Graceful error recovery with user-friendly messages
• Robust web scraping with fallback selectors

Browser Requirements

For Grind75 features, the application requires Chrome/Chromium to be installed. See BROWSER_SETUP.md for installation instructions if you encounter browser-related errors.

FAQ

1. How to obtain the LeetCode Session ID and CSRF Token?

For Premium users, both the session ID and CSRF token are required:

1. Open LeetCode in your browser and log in
2. Open Developer Tools (F12)
3. Go to Application → Cookies → https://leetcode.com
4. Copy both:
   • LEETCODE_SESSION → Use as LEETCODE_SESSION_ID in .env
   • csrftoken → Use as LEETCODE_CSRF_TOKEN in .env

See also: Failed to log in with a leetcode.com account #478

2. Why am I getting authentication errors with my Premium account?

Premium accounts require both the LEETCODE_SESSION_ID and LEETCODE_CSRF_TOKEN to be set in your .env file. Make sure both values are present and up-to-date. These cookies expire periodically, so you may need to refresh them.

3. How to obtain the Notion Page ID or Database ID?

Visit this Stack Overflow link: https://stackoverflow.com/a/67652092