Beatsync

Beatsync is a high-precision web audio player built for multi-device playback. The official app is beatsync.gg.

https://github.com/user-attachments/assets/2aa385a7-2a07-4ab5-80b1-fda553efc57b

Features

• Millisecond-accurate synchronization: Abstracts NTP-inspired time synchronization primitives to achieve a high degree of accuracy
• Cross-platform: Works on any device with a modern browser (Chrome recommended for best performance)
• Spatial audio: Allows controlling device volumes through a virtual listening source for interesting sonic effects
• Polished interface: Smooth loading states, status indicators, and all UI elements come built-in
• Self-hostable: Run your own instance with a few commands

[!NOTE] Beatsync is in early development. Mobile support is working, but experimental. Please consider creating an issue or contributing with a PR if you run into problems!

Quickstart

This project uses Turborepo.

Fill in the .env file in apps/client with the following:

NEXT_PUBLIC_API_URL=http://localhost:8080
NEXT_PUBLIC_WS_URL=ws://localhost:8080/ws

Run the following commands to start the server and client:

bun install          # installs once for all workspaces
bun dev              # starts both client (:3000) and server (:8080)

Directory	Purpose
apps/server	Bun HTTP + WebSocket server
apps/client	Next.js frontend with Tailwind & Shadcn/ui
packages/shared	Type-safe schemas and functions shared between client & server