About the missing body, it seems we forgot to include a common expressJs middleware on that app called body-parser. We just updated the app to fix that. If you pull the latest on the reference app you will be able to see the JSON responses in
undefined - some callbacks don’t include that in the JWT token. The body of the message will contain a sender id
req.body.message.sender.id that can be used to see who sent a message. The webhooks that do include the
userId on the JWT token are UI events, like card button presses.