NeetSync ⇆

Auto-sync your accepted LeetCode solutions to GitHub — the moment you hit Submit.

Every accepted submission is automatically committed to your GitHub repo as a study-ready note: your solution code, plus a README with the problem's difficulty, topic tags, your honest attempt count, runtime/memory stats, and space for your own notes and complexity analysis.

Why

LeetCode solutions live trapped inside LeetCode. Saving them somewhere you can actually revise from means manual copy-pasting after every solve. NeetSync removes that friction entirely: solve, submit, done — your repo grows on its own, organized by topic, with attempt counts kept honest (failed submissions are counted too).

How it works

flowchart TD
    A[You click Submit on LeetCode] --> B[interceptor.js<br/>patches fetch/XHR in the page's MAIN world]
    B --> C[content script<br/>relays result via postMessage]
    C --> D[background service worker<br/>records attempt + stats]
    D --> E{Accepted?}
    E -- No --> F[Stats only — no push]
    E -- Yes --> G[LeetCode GraphQL<br/>fetch title, difficulty, tags]
    G --> H[Build solution file + study note]
    H --> I[GitHub Contents API<br/>commit to your repo]

Loading

The key design decision: submissions are detected by intercepting network traffic, not by scraping the DOM. When you submit, LeetCode POSTs to /problems/<slug>/submit/ and then polls /submissions/detail/<id>/check/ until the judge finishes. A script injected into the page's MAIN world patches window.fetch and XMLHttpRequest to observe (never block) this flow — which survives LeetCode UI redesigns and yields the verdict, runtime, memory, and submitted code for free.

Because content scripts run in an isolated world and cannot see the page's fetch, the architecture requires three cooperating scripts:

Script	World	Job
interceptor.js	MAIN (page)	Patch fetch/XHR, capture submissions, postMessage results
content.js	Isolated	Inject the interceptor, validate + relay messages to the worker
background.js	Service worker	Record attempts, fetch metadata, push to GitHub

What gets pushed

your-solutions-repo/
└── Two-Pointers/
    └── 0005-longest-palindromic-substring/
        ├── solution.cpp     ← your accepted code
        └── README.md        ← difficulty, tags, attempts, runtime,
                               + Notes and Complexity sections for YOU to fill

The Notes/Complexity sections are deliberately left blank — filling them in right after solving is what turns a code dump into a revision resource.

Install (developer mode)

1. Clone this repo.
2. chrome://extensions → enable Developer mode → Load unpacked → select the neetsync/ folder.
3. Create a fine-grained GitHub PAT scoped to one solutions repo with Contents: Read and write only.
4. Click the NeetSync toolbar icon → enter token, username, and repo name → Save & test connection.
5. Solve something. Submit. Watch your repo.

Security notes

• The token is scoped to a single repo with Contents-only permission — worst case on leak is edits to that one solutions repo.
• The token is stored in chrome.storage.local, never transmitted anywhere except api.github.com.
• The interceptor observes network traffic; it never modifies requests or responses.

Built with

Vanilla JavaScript, Chrome Manifest V3 (service worker, MAIN-world script injection, web_accessible_resources, host_permissions), LeetCode GraphQL API, GitHub REST Contents API.

Repo structure

• neetsync/ — the extension (load this).
• learning-steps/ — the project built up in six self-contained, individually loadable steps, from a hello-world manifest to the full pipeline. Kept as documentation of the build process.

Roadmap

• Stats dashboard in the popup (solved counts, streaks, topic heatmap)
• Spaced-repetition review queue ("re-attempt these problems today")
• Multi-platform support (Codeforces, GeeksforGeeks)
• OAuth flow via a serverless token exchange (replacing the PAT)