Simple Text and Setting Variables

If you wish to send a text response and set variables within the platform, you need to use the following:

{
  "recipient": {
    "id": "USER_ID"
  },
  "message": {
    "text": "Hello world"
  },
  "set": {
    "$VARIABLE_NAME1": "VARIABLE_VALUE1",
    "$VARIABLE_NAMEn": "VARIABLE_VALUEn"
  }
}

Please note, you need to create the variables within the Bot Platform before you can store any data against them.