Session APIs allow you to manage a dynamic conversation on the client by defining the dialog state, slot values, prompts, and attributes. With the addition of checkpoint support you can now remember a point in the conversation. Checkpoints allow you to easily switch to an appropriate point in the conversation after a digression.
You can add a checkpoint using the Amazon Lex SDKs. The PutSession API can be used to add a checkpoint. You can define up to three checkpoints in a session. The capability is now available in the US East (N. Virginia), US West (Oregon) and EU West (Ireland) AWS Regions. For more information and to get started, please see the Amazon Lex documentation.