The components of `hid` are licensed as such:

 * `hidapi` is released under the [3-clause BSD](https://github.com/signal11/hidapi/blob/master/LICENSE-bsd.txt) license.
 * `libusb` is released under the [GNU GPL 2.1](https://github.com/libusb/libusb/blob/master/COPYING)license.
 * `go.hid` is released under the [2-clause BSD](https://github.com/GeertJohan/go.hid/blob/master/LICENSE) license.
 * `gowchar` is released under the [3-clause BSD](https://github.com/orofarne/gowchar/blob/master/LICENSE) license.

Given the above, `hid` is licensed under GNU GPL 2.1 or later on Linux and 3-clause BSD on other platforms.