...To listen to messages that your app has access to receive, you can use the message() method which filters out events that aren’t of type message. message() accepts an optional pattern parameter of type string or RegExp object which filters out any messages that don’t match the pattern. A RegExp pattern can be used instead of a string for more granular matching. Within your listener function, say() is available whenever there is an associated conversation (for example, a conversation where the event or action which triggered the listener occurred). say() accepts a string to post simple messages and JSON payloads to send more complex messages. ...