Node renderer

@image-marker/node@0.1 is a pure Node.js renderer powered by Sharp. It has no React or React Native dependency, accepts file paths, buffers, typed arrays, and readable streams, and can return a buffer, write a file, or produce a stream.

npm install @image-marker/node@^0.1 sharp@^0.35

Render on a server

import { readFile, writeFile } from 'node:fs/promises';
import { renderNodeImage } from '@image-marker/node';

const background = await readFile('photo.jpg');
const result = await renderNodeImage(
  {
    schemaVersion: 2,
    layers: [
      {
        id: 'title',
        type: 'text',
        text: 'Prepared for {{recipient}}',
        position: { position: 'topLeft', edgeInset: 32 },
        style: { color: '#FFFFFF', fontSize: 48, maxWidth: '60%' },
      },
    ],
    output: { saveFormat: 'webp', quality: 86, maxSize: 2048 },
  },
  {
    backgroundImage: { src: background },
    variables: { recipient: 'Alice' },
  }
);

await writeFile('marked.webp', result.data);

Use renderNodeImageToFile() for an atomic file-oriented workflow and renderNodeImageToStream() for HTTP responses. createNodeImageMarker() creates an injectable renderer with a process-level concurrency ceiling.

Batch and inspection

marker.renderMany() preserves input order and supports bounded concurrency, retry, progress, and AbortSignal cancellation. inspectNodeImage() returns encoded and display dimensions, format, EXIF orientation, alpha, channels, and density.

The package also provides authenticated lossless PNG locator helpers: embedNodeInvisibleLocator() and detectNodeInvisibleLocator(). Store keys in a secret manager. JPEG conversion, resizing, or destructive optimization can remove this locator.

For shell scripts and CI pipelines, use the Image Marker CLI. For mobile and browser rendering, use Core.