A Node client for the Facebook Messenger Platform. A verification token for the first-time setup of your webhook. Optional, but will be required by Facebook when you first set up your webhook. Your App Secret token used for message integrity check. If specified, every POST request will be tested for spoofing. As well, it mounts /_status, which will return {"status": "ok"} if the middleware is running. If verify is specified in the bot options, it will mount a handler for GET requests...