Announcing the express testing capability in Amazon Lex

Amazon Lex now provides the express testing capability on the AWS Management Console to expedite building your chatbot. You can start testing your bot soon after you initiate the build process without having to wait for the entire build to complete. You can use the new testing option to check the basic interaction elements such as the conversation flow, prompts, responses, and fulfillment logic.

Previously, you had to wait for the entire bot to build, which included multiple machine learning models, before you could confirm or test your changes. The new express testing feature allows you to confirm your changes with an intermediate model. You can start testing with exact input utterances right away and continue with more rigorous testing after the entire build is complete. This express testing capability enables you to test only exact matches with training data. With the new process, you can quickly iterate through the build and test phase, reducing the overall time required to deploy a bot in production.

How it works

After you choose Build, Amazon Lex starts preparing the build for express testing. You can view the status via the test window, as shown in the following screenshot.

Figure 1: Preparing build for express testing

For us-east-1, us-west-2, ap-southeast-2, or eu-west-1, scroll down to Advanced options and select Yes to opt in to the advanced features and enable the express testing capability. The feature is enabled by default in other Regions.

When the build completes for express testing, you can test utterances that are an exact match to the sample utterances in the test window. At this point you can test the dialog management, confirmation prompts, and the validation and fulfillment code hooks and responses. Amazon Lex completes the build process in the background.

Figure 2: Ready for express testing

You can test variations of the sample utterances after the bot build is complete. The build is then available for publishing to an alias, as shown in the following screenshot.

Figure 3: Complete build ready for deployment

When the build is successfully complete, the bot is ready for deployment, and you can publish the bot to enable complete conversations via interactive voice response (IVR), mobile apps, channels, and SDKs.


The new express testing capability for Amazon Lex allows you to accelerate iteration, test ideas, and make faster design decisions. The feature is available today in the N. Virginia, Oregon, Dublin, London, Sydney, Frankfurt, Tokyo, and Singapore regions.

For more information, see the Amazon Lex Developer Guide.

About the Authors

Esther Lee is a Product Manager for AWS Language AI Services. She is passionate about the intersection of technology and education. Out of the office, Esther enjoys long walks along the beach, dinners with friends and friendly rounds of Mahjong.

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