Chat21 is the default messaging engine of Tiledesk. Chat21 has a multi platform SDKs: native iOS and Android mobile SDKs and Web SDKs.
Widget, Web Chat and Native mobile apps are Chat21 modules.
Chat21 communicates with Tiledesk through webhooks. When a Chat21 event occurs - a new message arrives, a new member join a group, etc - a new Event is created and notified to Tiledesk Server. Chat21 then makes an HTTP POST request to send the Event to the Tiledesk webhook endpoint .