PNG, JPG, WebP

const png = await sone(doc).png();        // lossless, alpha
const jpg = await sone(doc).jpg(0.9);     // quality 0–1
const webp = await sone(doc).webp();      // smaller than PNG, alpha

All three return Promise<Buffer> — write directly to disk:

import fs from "node:fs/promises";
await fs.writeFile("out.png", await sone(doc).png());

Choosing a format

For OG images and social previews, JPG at quality 0.9 is usually the sweet spot.

Sizing

By default, the canvas auto-sizes to fit content. Set width / height explicitly when you need fixed dimensions (OG images, fixed-size cards):

await sone(doc, { width: 1200, height: 630 }).jpg(0.9);   // OG image

Background

await sone(doc, { background: "white" }).jpg();

Without background, transparent areas come out as transparent in PNG/WebP and as black in JPG.

DPR (high-DPI rendering)

Renderer DPR is platform-controlled — the Node renderer uses 1.0. To produce 2× output, scale width/height and let downstream consumers handle the scale factor.