Lightweight, Typed Event System for TypeScript

Documentation | Framework Bundle

A lightweight, fully typed event emitter for modern TypeScript projects. Provides a clean API, async emission, and zero dependencies — perfect for libraries and frameworks.

Feature

• Fully typed with TypeScript, no any.
• Provides simple on, off, once, and emit APIs.
• Supports async emission via emitAsync.
• Removes listeners automatically for once handlers.
• Zero dependencies and minimal footprint.

Installation

pnpm add @resolid/event
# or
npm install @resolid/event
# or
yarn add @resolid/event
# or
bun add @resolid/event

Usage

Basic

import { Emitter } from "@resolid/event";

const emitter = new Emitter();

emitter.on("hello", (name: string) => {
  console.log(`Hello, ${name}!`);
});

emitter.emit("hello", "World"); // -> "Hello, World!"

Once Listener

import { Emitter } from "@resolid/event";

const emitter = Emitter();

emitter.once("ready", (msg: string) => {
  console.log(msg);
});

emitter.emit("ready", "First call");  // -> "First call"
emitter.emit("ready", "Second call"); // won't trigger again

Async Emission

import { Emitter } from "your-package-name";

const emitter = Emitter();

emitter.on("done", () => {
  console.log("Event handled (after all sync code)");
});

console.log("Before emitAsync");

emitter.emitAsync("done");

console.log("After emitAsync");

// output
// Before emitAsync
// After emitAsync
// Event handled (after all sync code)

License

MIT License (MIT). Please see LICENSE for more information.