# QZ Tray connector (`qz-tray.js`)

- **Version:** 2.2.4
- **License:** LGPL-2.1-only (see the header of `qz-tray.js`)
- **Source:** copied unmodified from
  `quality_app-v2/app/static/js/qz-tray.js` (Gitea: `ske087/quality_app-v2`).
- **Local patch:** it **skips the certificate exchange** and connects to the
  custom QZ Tray service that authenticates with a **pairing key**
  (`PATCHED` markers around the original `_qz.websocket.connection.sendData({ certificate … })`).

Because the file is a modified LGPL-2.1 library, keep it under
`static/js/vendor/` and ship this notice plus the license header with it.
If you later use stock QZ Tray (certificate + signature), set
`window.CANTARIRE_QZ = { certificateUrl, signatureUrl }` before loading
`qz-print.js`; `qz-print.js` wires `qz.security.setCertificatePromise` and
`setSignaturePromise` when those URLs are provided.