{
    "attachments": [{
        "pretext": "This is the attachment pretext.",
        "text": "This is the attachment text.",
        "actions": [{
            "name": "Select an option...",
            "integration": {
                "url": "http://localhost:3000/message_menus_datasource",
                "context": {
                    "action": "do_something"
                }
            },
            "type": "select",
            "data_source": "channels"
        }]
    }]
}