TrackSync – The Music GitHub

Git for music co-production. Push WAV stems from LMMS, review pull requests in the browser, and resolve conflicts with side-by-side waveform comparison.

Built for UNIHACK 2026.

DEMO VIDEO: TRACKSYNC

How It Works

1. Create a project in the web app and copy the Project ID.
2. Connect LMMS via the TrackSync sidebar plugin — select a feature branch (not main).
3. Push — LMMS renders sample tracks to WAV and uploads them to the backend.
4. Review — open a pull request on the web to compare branches side by side.
5. Merge — resolve any conflicts (same track name, different audio) and merge into main.
6. Pull — download the merged tracks back into LMMS.

Each project is stored as a local Git repo on the server (tracks/*.wav per branch). The backend auto-mixes stems into a main preview track (main.mp3).

Tech Stack

• LMMS plugin: C++ / Qt sidebar — connect, push, pull, create PRs
• Frontend: React, Tailwind CSS, Wavesurfer.js (deployed on Vercel)
• Backend: FastAPI, GitPython, FFmpeg (deployed on Railway)
• Storage: Supabase (optional) with local JSON fallback

Live Demo

Service	URL
Web app	https://frontend-sigma-inky-bbx27rv9il.vercel.app
Backend API	https://backend-production-8b2a.up.railway.app

In LMMS, set the API URL to the web app URL (no /projects suffix). Vercel proxies API requests to Railway.

Quick Start (Local)

From the repo root:

# Backend
cd backend
python -m venv venv
source venv/bin/activate   # Windows: venv\Scripts\activate
pip install -r requirements.txt
uvicorn main:app --reload --port 8000

# Frontend (new terminal)
cd frontend
npm install
npm run dev

Or run both together from the repo root (requires backend venv already set up):

npm install
npm run dev

Open http://localhost:3000

Copy .env.example to .env and fill in values if using Supabase locally:

cp .env.example .env

Deployment

Backend (Railway):

• Root directory: backend
• Start command: uvicorn main:app --host 0.0.0.0 --port $PORT
• Mount a persistent volume at /app/data for Git repos and audio
• Set CORS_ORIGINS, SUPABASE_URL, SUPABASE_KEY in Railway variables

Frontend (Vercel):

• Root directory: frontend
• frontend/vercel.json proxies /projects and /audio to the Railway backend
• Set VITE_API_URL in Vercel env vars if not using the proxy rewrites

npm run deploy:frontend        # production
npm run deploy:frontend:preview  # preview

API Endpoints

Method	Path	Description
GET	/projects	List projects
POST	/projects	Create project
GET/PATCH/DELETE	/projects/{id}	Get / update / delete project
POST	/projects/{id}/cover	Upload album cover
GET	/projects/{id}/dashboard	Dashboard data (tracks, history, main mix)
GET/POST	/projects/{id}/branches	List / create branches
POST	/projects/{id}/push-files	Push WAV stems to a branch
GET	/projects/{id}/clone	Clone manifest for LMMS pull
POST	/projects/{id}/pull	Pull latest (server-side git)
GET	/projects/{id}/history	Commit timeline
GET/POST	/projects/{id}/prs	List / create pull requests
GET	/projects/{id}/pr/{prId}	Pull request detail + live diff
POST	/projects/{id}/pr/{prId}/merge	Merge with conflict resolutions
GET	/projects/{id}/conflict?track=X&pr=Y	Conflict audio URLs
POST	/projects/{id}/audio-diff	Compare two WAV files
GET	/audio/{id}/branch/{branch}/{path}	Stream audio from a git branch

Requirements

• FFmpeg (optional): mixes stems to MP3; Python WAV fallback used if unavailable
• Node 18+ for frontend
• Python 3.9+ for backend
• LMMS with TrackSync sidebar plugin (in lmms/ submodule) for DAW integration

License

MIT