Protocol

OpenKiosk architecture uses JSON-over-MQTT for backend-component communication, and JSON-over-Websocket for backend-frontend communication.

Everything described in this section is subjected to change in the future as the project evolves.

Commands are instructions sent from the backend to the microservice components. For example: a “start” command is sent to the bill acceptor in order to get it ready to start accepting bills.

{
    "cmd": "start",
    "data": "this field exists but is ignored in this case!"
}

Events are caused by user interactions or they’re results of commands issued by the backend. For example: after a bill acceptor has been started, it will send events for the amount of bills inputted.

{
    "event": "moneyin",
    "data": {
        "amount": 100,
        "currency": "eur"
    }
}