Understanding conversation flow management - Amazon Lex

Understanding conversation flow management

On August 17, 2022 Amazon Lex V2 released a change to the way that conversations are managed with the user. This change gives you more control over the path that the user takes through the conversation.

Before the change, Amazon Lex V2 managed the conversation by eliciting slots based on their priorities in intent. You could modify this behavior dynamically and change the conversation path based on user inputs by using DialogAction in Lambda function. This could be done by keeping track of the conversation's current state and programmatically deciding what to do next based on the session state.

With this change, you can create conversational paths and conditional branches using the Amazon Lex V2 console or APIs without using a Lambda function. Amazon Lex V2 tracks the state of the conversation and controls what to do next based on conditions defined when the bot is created. This enables you to easily create complex conversations while designing your bot.

These changes give you complete control over the conversation with your customer. However, you are not required to define a path. If you do not specify a conversation path, Amazon Lex V2 creates a default path based on the priority of slots in your intent. You can continue to use Lambda functions to define conversation paths dynamically. In such a scenario, the conversation resumes based on the session state configured in the Lambda function.

This update provides the following:

  • A new console experience for creating bots with complex conversation flows.

  • Updates to the existing APIs for creating bots to support the new conversation flows.

  • An initial response to send a message on intent invocation.

  • New responses for slot elicitation, Lambda invocation as dialog code hook and confirmation.

  • Ability to specify next steps at each turn of the conversation.

  • Evaluation of conditions to design multiple conversation paths.

  • Setting of slot values and session attributes at any point during the conversation.

Note the following for older bots:

  • Bots created before August 17, 2022 continue to use the old mechanism to manage conversation flows. Bots created after that date use the new way of conversation flow management.

  • New bots created via imports after August 17, 2022 use the new conversation flow management. Imports on existing bots continues to use the old way of conversation management.

  • To enable the new conversation flow management for a bot created before August 17, 2022, export the bot, and then import the bot using a new bot name. The newly created bot from the import uses the new conversation flow management.

Note the following for new bots created after August 17, 2022:

  • Amazon Lex V2 follows the defined conversation flow exactly as designed to deliver the desired experience. You should configure all flow branches in order to avoid default conversation paths during runtime.

  • Conversation steps following a code hook should be fully configured, because incomplete steps can lead to bot failure. We recommend that you validate bots created before August 17, 2022, because for these bots, there is no automatic validation of conversation steps following a code hook.