Business Chat with Custom CSP platform

We are planning to have chat bot using Business chat. We are trying to do a POC around it and have few questions on the same.

  We already have custom bot framework where the user messages gets processed and send back the response. Already this framework is integrated with multiple channels like web bot, facebook , SMS , Email etc by creating a adapter for each channel. Similarly we are planning to create a adapter using nodejs technology for business chat. Would need your help on how the flow works when we have our own adapter. Our current flow for web bot or facebook bot is like below

 - User sends "hi" - our facebook or web adapter in nodejs gets triggered - it sends the user message to AWS lex for intent identification - Our adapter will identify the response for that intent and sends back the response to web or facebook channel.  

We are looking same flow for business chat where user sends 'hi' input in message/business chat app - hits our business chat adapter written in nodejs - our adapter will get the intent and identify the response - Sends back to business chat.

Need some guidance on this like where to call our custom business chat adapter here.

Business Chat with Custom CSP platform
 
 
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