Run Pts.js from the command line.

pts-render creates images and SVGs directly without a browser.

$ npx pts-render interpolate.mjs

pts-output/interpolate-<render-id>.png

Simple interface

Export one function with Pts drawing code, and run npx pts-render file.mjs.

Alternatively, install globally via npm i -g pts-render and run pts-render file.mjs.

Pts.js code sample

interpolate.mjs

export default function run({ Pts, space, form }) {
  const { Geom, Num, Rectangle } = Pts;

  function interpolate(points, t, depth = 0) {
    if (depth > 20) return;
    t = Num.boundValue(t, 0, 1);
    const next = points.map((p, i) =>
      Geom.interpolate(p, points[(i + 1) % points.length], t),
    );
    form.fillOnly(depth % 2 === 0 ? "#fff" : "#123").polygon(next);
    interpolate(next, t + 0.02, depth + 1);
  }

  space.add(() => {
    const size = space.size.$multiply(0.5).minValue().value;
    const rect = Rectangle.corners([
      space.center.$subtract(size),
      space.center.$add(size),
    ]);
    const t = 0.15;
    interpolate(rect, t);
  });
}

Render it from command line

$ npx pts-render interpolate.mjs \
  --out interpolate.png \
  --out interpolate.svg

$ npx pts-render interpolate.mjs \
  --size 1200x630 \
  --out card.png

Size and background are optional. They default to 800 × 600 and transparent.

You can also use the same file in a browser

import { mountScene } from
  "pts-render/browser";
import run from "./interpolate.mjs";

await mountScene(run, {
  target: "#pt"
});

Features

Repeatable renders: Control the frame, input, parameters, and random seed when a stable result matters.
CLI and API: Use the pts-render command or call renderScene() from Node.
Structured results: Request JSON output for build scripts, automation, and agents.
More: See other Pts options like Python and React in this ecosystem guide.