@taffyjs/wasm

@taffyjs/wasm runs the same TaffyJS API through WebAssembly. Choose it for a bundled browser application, or when you want to use WebAssembly explicitly in Node.js instead of loading a native addon.

Read the Design Philosophy to understand how the package keeps one direct API across native and WebAssembly runtimes.

Install

npm install @taffyjs/wasm

Import it like the native package. There is no separate initialization call:

import { TaffyTree } from "@taffyjs/wasm";

const tree = new TaffyTree();
const root = tree.newLeaf({ size: { width: 120, height: 80 } });

tree.computeLayout({
  root,
  availableSpace: { width: 800, height: 600 },
});

console.log(tree.getLayout(root).size); // { width: 120, height: 80 }

The Guide and TaffyTree reference use @taffyjs/node, but the tree, style, measurement, and layout APIs shown there also apply to @taffyjs/wasm. Change the package name in the import; the rest of the code stays the same.

Where it runs

Environment	Support
Node.js	Node.js 22.20 or newer
Bun	Version 1.2 or newer within the Bun 1 major
Deno	Version 2.2 or newer within the Deno 2 major, without permission flags
Browser	Applications built with a bundler that supports package export conditions and top-level await

The browser build contains the Wasm payload inside JavaScript, so it does not fetch a separate .wasm file. It is threadless and does not require SharedArrayBuffer or cross-origin isolation headers.

Bun versions below 1.2, Deno versions below 2.2, other Bun and Deno majors, direct CDN imports, and runtimes not listed above are not part of the package contract.

Loading

A normal static import is ready to use when the module finishes loading. In a browser, the module waits for WebAssembly compilation as part of loading:

import { TaffyTree } from "@taffyjs/wasm";

If the layout engine is not needed at startup, use a standard dynamic import:

const { TaffyTree } = await import("@taffyjs/wasm");

Your bundler must select the package's browser entry. No TaffyJS-specific loader or initialization function is required.

Compared with @taffyjs/node

	@taffyjs/node	@taffyjs/wasm
Engine	Taffy compiled as a native addon	Taffy compiled to threadless WebAssembly
Main use	Supported native platforms	Bundled browsers and supported runtimes
Public layout API	Direct TaffyJS API	The same direct TaffyJS API
Initialization visible to users	None	None
Distribution	Platform-specific native binary	Wasm payload embedded in JavaScript

The package choice is explicit. @taffyjs/node does not silently fall back to WebAssembly, and @taffyjs/wasm does not switch to the native addon.