bch --help
Usage: bch [OPTIONS] COMMAND [ARGS]...

Options:
  --gateway TEXT                 Gateway name [default: usb-dongle].
  -H, --mqtt-host TEXT           MQTT host to connect to [default: 127.0.0.1].
  -P, --mqtt-port INTEGER RANGE  MQTT port to connect to [default: 1883].
  --mqtt-username TEXT           MQTT username.
  --mqtt-password TEXT           MQTT password.
  --mqtt-cafile PATH             MQTT cafile.
  --mqtt-certfile PATH           MQTT certfile.
  --mqtt-keyfile PATH            MQTT keyfile.
  --base-topic-prefix TEXT       MQTT topic prefix [default: ''].
  -v, --verbosity LVL            Either CRITICAL, ERROR, WARNING, INFO or
                                 DEBUG

  --version                      Show the version and exit.
  -h, --help                     Show this message and exit.

Commands:
  gw       Gateway
  node
  pairing
  pub
  sub      Subscribe topic.