@sixtyfold/ssr

Server-side Canvas2D rendering for Sixtyfold line and stock charts. Supply a canvas implementation such as @napi-rs/canvas; Sixtyfold does not force a specific canvas dependency on consumers.

pnpm add @sixtyfold/ssr @napi-rs/canvas

import { createCanvas } from "@napi-rs/canvas";
import { renderLineChartSSR } from "@sixtyfold/ssr";

const canvas = createCanvas(1200, 600);

renderLineChartSSR(
  canvas,
  {
    x: new Float64Array([0, 1, 2]),
    series: [new Float64Array([4, 7, 5])],
    length: 3,
    seriesCount: 1,
  },
  { animated: false },
  { width: 1200, height: 600, dpr: 1 },
);

const png = canvas.toBuffer("image/png");

@napi-rs/canvas is shown only as an example and is not a dependency of this package.

Verified server runtimes

The same ESM package and @napi-rs/canvas backend render and encode real PNG output in the current compatibility table:

| Runtime | CI version | Command | | ------- | ---------: | ----------------------------------------------------------------------------------------------------- | | Node.js | 22.22.3 | node app.mjs | | Bun | 1.3.14 | bun app.mjs | | Deno | 2.9.3 | deno run --allow-read --allow-env --allow-ffi --allow-sys=homedir --node-modules-dir=manual app.mjs |

Deno needs a local node_modules tree for the Node-API canvas addon. Its permissions allow module and font discovery, environment inspection, native addon loading, and the canvas backend's home-directory lookup. Add --allow-write=<output-directory> only when the application writes encoded images to disk.

Maintainers can run the complete runtime compatibility set with:

pnpm run test:ssr:runtimes

The compatibility test renders Line and Stock fixtures without network access, checks plot pixels against a pinned visual reference, and requires every named label to produce visible ink at its exact layout anchor inside a bounded region. The text check does not pin font-dependent glyph widths or ink ratios across operating systems. It also validates PNG signatures and dimensions and writes inspectable files under artifacts/ssr-runtimes/.

Before either release workflow publishes, the Node visual reference is repeated on Ubuntu, macOS, and Windows.

Licensing

This package is source-available under the PolyForm Noncommercial License 1.0.0.

For current licensing, commercial terms, and prices, see Licensing and Commercial Terms and Pricing.