Introduction

What is it?

tabus-js is a dependency-free TypeScript library that lets you send and receive typed events between tabs or windows of the same browser (or between multiple instances within the same process).

It uses the native BroadcastChannel API when available, and when it isn’t (SSR, unsupported environments, Node), it automatically falls back to an in-memory bus within the same process.

Note

The bus is identified by a channel name. All instances created with the same name — in any tab of the same origin — communicate with each other.

What is it for?

Typical use cases:

• Syncing state across tabs: for example, logging out in one tab and reflecting it in all the others.
• Cross-tab notifications: telling other tabs that an event happened (new data saved, cart updated, etc.).
• Detecting the presence of other tabs: knowing how many tabs of the app are open, using the tab:join / tab:leave events.
• Coordinating actions: preventing two tabs from doing the same task in parallel (simple locks, leader/follower).
• SSR-safe: works on the server without throwing errors, because it uses the in-memory fallback when BroadcastChannel doesn’t exist.

Next step

Continue with Installation to add tabus-js to your project, or jump straight to Quick start to see basic usage step by step.