You can create a SimpleX Chat chat-bot with 17 lines of JS code using the new Node.js library
Beta version: https://npmjs.com/package/simplex-chat/v/6.5.0-beta.4.4
Source code: 
To run this example with Node.js:
npm i simplex-chat@6.5.0-beta.4.4
node ./node_modules/simplex-chat/examples/squaring-bot-readme.js
Beta version: https://npmjs.com/package/simplex-chat/v/6.5.0-beta.4.4
Source code: GitHub
simplex-chat/packages/simplex-chat-nodejs at master · simplex-chat/simplex-chat
SimpleX - the first messaging network operating without user identifiers of any kind - 100% private by design! iOS, Android and desktop apps 📱! ...
