The engine in the browser

npm install @inkoxide/wasm

import { init, registerFont, renderSync, InkoxideError } from '@inkoxide/wasm';

// Once: compiles `inkoxide.wasm`, which bundlers resolve next to this module.
await init();
registerFont('Inter-Regular', new Uint8Array(await (await fetch('/fonts/Inter-Regular.ttf')).arrayBuffer()));

const doc = {
  version: 1,
  fonts: [{ id: 'Inter-Regular', family: 'Inter' }],
  pages: [{ size: { width: 595.28, height: 841.89 },
            children: [{ type: 'text', runs: [{ text: 'Hello', font: 'Inter-Regular', size: 24 }] }] }],
};

try {
  const pdf = renderSync(JSON.stringify(doc));
  const url = URL.createObjectURL(new Blob([pdf], { type: 'application/pdf' }));
} catch (e) {
  if (!(e instanceof InkoxideError)) throw e;
  console.error(e.code, e.path, e.message);
}

How it differs from inkoxide:

• One thread. Renders run on the calling thread, render included: in a page, render in a Web Worker. threads may only be 1.
• JSON only. format: 'msgpack' is a PARSE_ERROR.
• Downloads on demand. The module (about 1.2 MB with brotli) leaves out the built-in hyphenation patterns: render fetches a language's from hyphenation/ next to the module the first time a document hyphenates text in it, and the fonts of its deferredFonts option (id → URL) that a document draws with, or needs as a fallback. renderSync cannot fetch, and fails with NOT_LOADED: call loadHyphenation(['de']) first, or use render.
• init(source?) takes a URL, a Response, the bytes or a compiled WebAssembly.Module. It needs no cross-origin isolation; a Content Security Policy needs script-src 'wasm-unsafe-eval'.
• A bug in the engine (INTERNAL) ends its instance: the next call runs in a new one, with the fonts and hyphenation patterns registered so far, which the package keeps a copy of.
• Memory grows and is not given back. clearCaches() empties the caches renders share, for later renders to reuse the memory.
• Fonts. A WOFF2 font gives other PDF bytes than its TrueType file.

From a CDN, give init the module with its Subresource Integrity hash, so that the browser refuses any other bytes, and the folder of the hyphenation patterns:

const base = 'https://cdn.jsdelivr.net/npm/@inkoxide/wasm@<version>/';
await init(fetch(`${base}inkoxide.wasm`, { integrity: 'sha384-<hash of inkoxide.wasm>' }), {
  hyphenation: `${base}hyphenation/`,
});

The README published with each version on npm has its version and hash here.

Options, defaults and error codes are typed in index.d.ts and described in the API reference.