@v5x/serial implements the V5 serial protocol in TypeScript. It provides a high-level device model for connections, brain state, programs, files, controllers, smart devices, radio state, and screenshots. 
import { V5SerialDevice } from "@v5x/serial";

const device = new V5SerialDevice(navigator.serial);

try {
  if (!(await device.connect())) throw new Error("V5 device not found");
  console.log(device.brain.systemVersion.toUserString());
} finally {
  await device.dispose();
}
Web Serial requires a secure context and explicit user permission. Browser support is not universal.
The package also exports packet-level protocol classes. Those are advanced internals and are not covered by this high-level guide.