Amazon Lex Documentation

Amazon Lex provides a scalable, end-to-end solution to build, publish and monitor your bots. Amazon Lex provides you with the tools to tackle challenging deep learning problems, such as speech recognition and language understanding. Once built, your bot can be deployed directly to chat platforms, mobile clients, and IoT devices. You can also use the reports provided to track metrics for your bot. 

Natural conversations

Speech recognition and natural language understanding

Amazon Lex provides automatic speech recognition and natural language understanding technologies to create a speech language understanding system. Amazon Lex is designed to learn the multiple ways users can express their intent based on sample utterances provided by the developer. 

Context management

As the conversation develops, being able to classify utterances accurately requires managing context across multi-turn conversations. Amazon Lex supports context management natively, so you can manage the context directly without the need for custom code. As initial prerequisite intents are filled, you can create “contexts” to invoke related intents. This simplifies bot design and expedites the creation of conversational experiences.

Multi-turn dialog

Amazon Lex bots provide the ability for multi-turn conversations. Once an intent has been identified, users can be prompted for information that is required for the intent to be fulfilled (for example, if “Book hotel” is the intent, the user can be prompted for the location, check-in date, number of nights, etc.). Amazon Lex allows you to build multi-turn conversations for your chatbots—you simply list the slots/parameters you want to collect from your bot users, as well as the corresponding prompts, and Amazon Lex orchestrates the dialogue by prompting for the appropriate slot.

Builder productivity

Lifecycle Management Capabilities

Amazon Lex lets you apply versioning to the Intents, Slot Types, and Bots that you create. Versioning and rollback mechanisms enable you to maintain code as you test and deploy in a multi-developer environment. You can create multiple aliases for each Amazon Lex bot and associate different versions to each such as “production,” “development,” and “test”. This allows you to continue making improvements and changes to the bot and release them as new versions under one alias.

Multi-platform deployment

Amazon Lex allows you to easily publish your bot to chat services directly from the Amazon Lex console, reducing multi-platform development efforts. Rich formatting capabilities provide an intuitive user experience tailored to popular chat services.

Streaming conversations

Natural conversations are punctuated with pauses and interruptions. For example, a caller may ask to pause the conversation or hold the line while looking up the necessary information before answering a question. Streaming conversation APIs are designed to allow you to pause a conversation and handle interruptions directly as you configure the bot, and to enhance the conversational capability of virtual contact center agents or smart assistants.

Additional Information

For additional information about service controls, security features and functionalities, including, as applicable, information about storing, retrieving, modifying, restricting, and deleting data, please see This additional information does not form part of the Documentation for purposes of the AWS Customer Agreement available at, or other agreement between you and AWS governing your use of AWS’s services.