a computer program designed to simulate conversation with human users

"Bots are the new apps," declared Microsoft CEO Satya Nadella in 2016

They are all the rage, but why?

  • Investments from Kik, Facebook Messenger, Microsoft, Amazon
  • Plain tired of downloading apps
  • People live in chats (within messenger apps)
  • Access within SMS/txt, Skype, WeChat, Slack, Line, Telegram, Twitter
  • Advancements in key NLP and AI tech so that even non-programmers might be able to create simple but useful chatbots

Amazon Lex

  • Platform launched to all users - April 20th, 2017

  • Service for building conversational interfaces into any application using voice and text.

  • Same deep learning technologies that power Amazon Alexa

  • Pre-trained models on massive amounts of data and infrastructure

  • Bots can be published to messaging platforms like Facebook Messenger, Slack, and Twilio SMS

Amazon Lex Ecosystem

Validation and External Service Integration - Amazon Lambda
  • Lets you run code without provisioning or managing servers
  • Set up your code to automatically trigger from other AWS services


  • Intents - An intent represents an action that the user wants to perform. eg: "I want to order a pizza"

  • Slots- To fulfill an intent, the Amazon Lex bot needs information from the user. eg: the OrderPizza intent requires slots such as pizza size, crust type, and number of pizzas.

Lex API Response Fields

  • sessionAttributes - if you want to include any session attributes in the response

  • Close- Informs Amazon Lex not to expect a response from the user.

  • Delegate- Directs Amazon Lex to choose the next course of action based on the bot configuration.

  • ElictSlot— Informs Amazon Lex that the user is expected to provide a slot value in the response.