TypeScript client for QSC's Q-SYS Remote Control (QRC) protocol — the null-terminated JSON-RPC-over-TCP interface every Q-SYS Core (and Q-SYS Designer in Emulate mode) serves on port 1710.

Handles the wire framing, request/response correlation, change groups, keepalive, and transparent auto-reconnect, and ships shared types for controls, components, and engine status. It is the core that the qsys CLI and the q-sys-mcp server build on.

Install

npm install qsys-qrc

Usage

import { QrcClient } from 'qsys-qrc';

const qrc = new QrcClient({ host: '192.168.1.10' });
await qrc.connect();

const status = await qrc.statusGet();          // typed helpers…
await qrc.setControl('MainGain', -6, 2);       // value -6, 2 s ramp
const [gain] = await qrc.getControl(['MainGain']);

await qrc.send('Component.GetComponents');     // …or raw QRC methods

qrc.close();

Typed helpers cover the whole protocol surface: status, components, named controls, change groups (poll-based watch), and snapshots.

The client keeps the socket alive (NoOp keepalive) and reconnects transparently if the Core drops the connection. In-flight reads are retried on the new socket; an in-flight mutation whose response was lost rejects with QrcIndeterminateError instead of being retransmitted — QRC has no request dedup, so a blind retry could double a trigger or playback start. Re-read state (or re-issue explicitly) to reconcile.

Disclaimer

This is an independent open-source project, not affiliated with, endorsed by, or supported by QSC, LLC. "Q-SYS" is a trademark of QSC. The client speaks the publicly documented QRC protocol and contains no QSC code.