nothing-qrcpp

Typed event callbacks and manual control API for the C++ QR detector built into the Nothing Browser binary (PiggyQRDetector).

The detector runs automatically — you do not need this package to receive QR events. It exists for discoverability, typed callbacks, and the site.qr control API.

Install

npm install nothing-qrcpp

Usage

const piggy  = require('nothing-browser').default;
const qrcpp  = require('nothing-qrcpp');
const fs     = require('fs');

await piggy.launch({ mode: 'tab', binary: 'headless' });
await piggy.register('whatsapp', 'https://web.whatsapp.com', { single: true });

await piggy.extend(
  qrcpp({
    onQR:      (d) => console.log(`Scan this QR (attempt ${d.attempts}):`, d.qrData),
    onScanned: ()  => console.log('Authenticated!'),
    onTimeout: ()  => console.log('QR rotated — new one incoming...'),
  })
);

await piggy.whatsapp.navigate();

Without this package

If you don't want the dependency, you can listen directly — the C++ emits these events regardless:

piggy.whatsapp.on('qr',         (d) => console.log('Scan:', d.qrData));
piggy.whatsapp.on('qr:scanned', ()  => console.log('Done!'));
piggy.whatsapp.on('qr:timeout', ()  => console.log('Rotated'));

Options

| Option | Type | When called | |---|---|---| | onQR | function | New or rotated QR is ready. data.qrData is "data:image/png;base64,..." | | onScanned | function | QR scanned, WAWeb authenticated | | onTimeout | function | QR expired and rotated (~every 20s) |

Events

| Event | Data | When | |---|---|---| | qr | { tabId, qrData, attempts } | New QR ready — qrData is a base64 PNG data URL | | qr:scanned | { tabId } | Canvas disappeared — auth succeeded | | qr:timeout | { tabId } | QR rotated before being scanned |

API (site.qr)

// Check current QR state
const state = await piggy.whatsapp.qr.status();
// { waiting: true, attempts: 2 }

// Force an immediate canvas check (skips the 500ms poll interval)
await piggy.whatsapp.qr.force();

How the C++ detector works

• Polls the page every 500ms for a <canvas> matching known WAWeb QR selectors
• Extracts the canvas as a base64 PNG via canvas.toDataURL()
• Hashes the image to detect rotation — only emits qr when the image actually changes
• Prints the QR to the terminal automatically using iTerm2/Kitty inline image protocol with a plain data URL fallback
• When the canvas disappears, emits qr:scanned and stops polling

Notes

• To force a fresh QR scan: call site.storage.clear() before navigating (requires nothing-innerstorage)
• This plugin was made upon request — report any issues found
• This plugin is tailored specifically for WhatsApp sessions. You can use it on other sites but there is no guarantee it will work, and that is not a bug. A general-purpose nothing-storage plugin will be released in the future to solve that
• qrData is a data:image/png;base64,... URL — render it in a browser, pass it to a QR library, or display it in the terminal. The C++ already prints it automatically
• The QR is canvas-based in WAWeb — there is no <img> tag. Do not try to read it with find.css() or provide.text()