Sending
Give the inbox an address to reply to and a way to send:send runs inside your app and receives to, subject, text, thread, the item (with its data) and the actor who wrote it. If your app is offline, the reply waits and the timeline says so until it goes out.
Threading replies
thread identifies the item’s conversation. Put it somewhere a reply carries back: a plus address like above, or a header your provider keeps. When your provider’s inbound webhook reaches your app, hand the message to Pult:
receive returns null for a thread Pult doesn’t know, so a new conversation becomes whatever you decide; above, a new support item.