find grabs the first match. With more than one box, find_medius lists every match as a PortInfo (path, vid, pid) without opening, then open the chosen one.

use medius::{Device, find_medius};

let ports = find_medius();
for port in &ports {
    println!("{} (vid={:#06x} pid={:#06x})", port.path, port.vid, port.pid);
}

// open a chosen one (here, the first):
let port = ports.first().ok_or(medius::Error::NotFound)?;
let dev = Device::open(&port.path)?;

Device is Send + Sync and clones cheaply (an Arc inside), so one connection serves any number of threads; a clone bumps the reference count and doesn't reopen the port.

use std::thread;

let worker = device.clone();
let handle = thread::spawn(move || {
    worker.move_rel(10, 0)
});
handle.join().unwrap()?;

AsyncDevice clones the same way, so hand a clone to another task and await both queries together with futures::future::join.

let (v, h) = futures::future::join(
    device.query_version(),
    device.query_health(),
).await;
let v = v?;
let h = h?;
println!("{v}, link_up={}", h.link_up);

The box clears every injected input and pending move once no frame arrives for its silence window. A live Device holds your overrides past that on its own: a background thread (medius-keepalive) sends a QUERY(HEALTH) every DEFAULT_KEEPALIVE_CADENCE (500 ms) while anything is held, so a press survives. There's no keepalive() to call.

device.press(Button::Left)?;

// No further calls. The keepalive thread sends QUERY(HEALTH) on its own,
// so the hold survives well past the 1000 ms silence window.
std::thread::sleep(std::time::Duration::from_secs(5));

device.reset()?;

An override is the box holding an input down or up itself, set by press or force_release; the library keeps a copy. After a dropped link, reapply and reconnect restore it.

There's no close: dropping the last Arc-backed handle tears the connection down. Its Drop stops the threads and closes the port.

For immediate hand-off call reset before drop.

// hand the mouse back right now, not a second from now:
device.reset()?;   // box returns to passthrough immediately
drop(device);      // tears down threads and closes the port