qmk_firmware/keyboards/zvecr/zv48/keymaps/xap/xap.hjson

{
    routes: {
        0x01: {
            type: command
            name: Capabilities Query
            define: CAPABILITIES_QUERY_USER
            description:
                '''
                USER subsystem capabilities query. Each bit should be considered as a "usable" route within this subsystem.
                '''
            return_type: u32
            return_purpose: capabilities
            return_constant: XAP_ROUTE_USER_CAPABILITIES
        }
    }
}