iohidmanager

Safe Rust bindings for Apple's IOKit HID subsystem on macOS — enumerate connected mice, keyboards, gamepads, and other HID devices.

Status: actively developed. v0.5 ships the current public IOHIDManager / IOHIDDevice / IOHIDElement / IOHIDValue C header surface in raw FFI, plus safe wrappers for multi-match dictionaries, element discovery, report I/O, value access, report-descriptor reads, and live input callbacks.

Pure C — zero Swift bridge (like cgevents, imageio, videotoolbox).

Quick start

use iohidmanager::prelude::*;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let manager = HidManager::new()?;
    manager.set_device_matching(None)?;

    for d in manager.devices() {
        println!(
            "[{:04x}:{:04x}] {} — {} ({})",
            d.vendor_id.unwrap_or(0),
            d.product_id.unwrap_or(0),
            d.manufacturer.as_deref().unwrap_or("?"),
            d.product.as_deref().unwrap_or("?"),
            d.transport.as_deref().unwrap_or("?"),
        );
    }

    let kb_or_mouse = [
        DeviceMatch::usage(HidUsage::Keyboard),
        DeviceMatch::usage(HidUsage::Mouse),
    ];
    manager.set_device_matching_multiple(&kb_or_mouse)?;
    println!("{} keyboards/mice connected", manager.devices().len());
    Ok(())
}

Pipeline composition

iohidmanager (enumerate + inspect + subscribe) ──► your custom dispatch
                                               │
                                               ├─► gamepad-mapper
                                               ├─► macropad-driver
                                               └─► hardware-token authentication

Pairs naturally with cgevents (synthesise events triggered by HID input) and carbonhotkey (more focused: just global hotkeys).

Roadmap

• HidManager::new() + open
• set_device_matching(Option<HidUsage>) convenience filter
• DeviceMatch / ElementMatch builders + multi-match dictionaries
• devices() enumeration with vendor/product/usage/serial/transport snapshots
• live_devices() handles for per-device work
• Live input-report callbacks (on_input_report, on_input_report_with_timestamp)
• Live input-value callbacks (on_input_value)
• Element discovery + metadata (elements, matching_elements, HidElement accessors)
• HidValue creation + synchronous reads (get_value, get_value_with_options)
• Synchronous report read / write (get_report, set_report)
• Generic property helpers + report-descriptor reads
• Dispatch-queue convenience wrappers
• Safe manager-level add/remove/value/report callback wrappers

License

Licensed under either of Apache-2.0 or MIT at your option.