Node

npm install @jvoltci/naina

Inference runs on a libuv worker thread, so a read never blocks the event loop.

Read a page

import { read } from '@jvoltci/naina';

const page = await read('invoice.png', { tier: 'small' });

console.log(page.markdown);
console.log(page.text);

for (const line of page.lines) {
  console.log(line.confidence.toFixed(3), line.text);
}

Reuse the reader

import { Reader } from '@jvoltci/naina';

const reader = new Reader({ tier: 'small' });
try {
  for (const file of await readdir('scans')) {
    const page = await reader.read(join('scans', file));
    console.log(page.markdown);
  }
} finally {
  reader.close();          // releases the native context
}

close() matters. The context holds loaded models — tens to hundreds of megabytes — and it is not released by garbage collection.

Raw pixels

const page = await reader.readRgb(rgbBuffer, width, height);

rgbBuffer is packed RGB8, width * height * 3 bytes. Use this with sharp, canvas, or frames from a video pipeline.

Layout regions

for (const r of page.regions.sort((a, b) => a.order - b.order)) {
  console.log(r.order, r.kind, r.bbox);
}

TypeScript

Types ship with the package; no @types install.

import { Reader, type NainaPage, type NainaLine } from '@jvoltci/naina';

Configuration

Reads the same environment variables as every other binding: NAINA_CACHE, NAINA_OFFLINE, NAINA_REGISTRY. See Python.

Setting them from Node

The native addon reads these with getenv() at load time. Writing process.env.NAINA_CACHE from inside a worker thread does not always reach it — under vitest's default thread pool it does not. Set them in the environment before the process starts, or use pool: 'forks'.