🚀 LeetCode Journey Sync

A fully automated pipeline for synchronizing LeetCode progress to GitHub, featuring incremental updates, time-travel commits, and robust rate-limit handling.

🌟 Introduction

This repository serves as my personal algorithm knowledge base. Instead of manually copying and pasting solutions, I built this automated synchronization tool. It routinely pulls my Accepted submissions from LeetCode via its GraphQL API and commits them to this repository.

More than just a backup tool, this project is an exercise in Automation, API Integration, and Idempotent Data Synchronization.

Key Features

• Automated Sync: Runs daily via GitHub Actions (cron jobs) with zero manual intervention.
• Time-Travel Commits: Preserves the exact historical timestamp of the original LeetCode submission (GIT_AUTHOR_DATE), ensuring an accurate timeline of learning progress on the contribution graph.
• Incremental Updates: Uses local state tracking (synced_ids.txt) to avoid duplicate requests, skipping previously synced problems instantly.
• Robust Error Handling: Gracefully handles LeetCode's rate limiting (HTTP 429 / Empty Responses) through exponential backoff and resume capabilities.

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🛠️ Technical Stack

• Language: Python 3
• API: LeetCode GraphQL API
• CI/CD: GitHub Actions
• Version Control: Git (Subprocess manipulation)

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📂 Project Structure

.
├── .github/workflows/
│   └── leetcode_sync.yml   # GitHub Actions automation pipeline
├── solutions/              # Auto-generated folder containing all accepted codes
├── synced_ids.txt          # Local state file for incremental sync tracking
├── sync_leetcode.py        # Core Python synchronization script
└── README.md               # You are here

⚙️ How It Works (For Developers)

1. Retrieve Your LeetCode Cookies

• Log into LeetCode (CN).
• Open Developer Tools (F12) and navigate to the Network tab.
• Filter by graphql and inspect the Request Headers.
• Extract the following two values:
  • LEETCODE_SESSION (from the Cookie string)
  • csrftoken (from the x-csrftoken header)

2. Configure GitHub Secrets Go to your repository settings -> Secrets and variables -> Actions and add:

• LEETCODE_SESSION (Required)
• LEETCODE_CSRF_TOKEN (Required)
• LEETCODE_REGION (Optional): Set to US for global leetcode.com. Defaults to CN (leetcode.cn) if omitted.

3. Configure Email To ensure GitHub correctly attributes the commits to your account, update the GIT_EMAIL variable in sync_leetcode.py with your GitHub-associated email (or use your no-reply privacy email).

4. Run the Pipeline

• Once configured, the Action runs automatically every day at 16:00 UTC.
• You can also trigger it manually via the Actions tab -> Run workflow.

⚠️ Important Precautions

• Region Note: This script defaults to LeetCode China (leetcode.cn). If you use the global version, set the LEETCODE_REGION secret to US.
• Rate Limiting: If migrating a large amount of historical data (e.g., 100+ problems), LeetCode may temporarily rate-limit the requests. The script safely ignores these errors. Simply run the workflow a few more times; it will incrementally catch up.