Amazon Lex is an AWS service for building conversational interfaces for any applications using voice and text. With Amazon Lex, the same conversational engine that powers Amazon Alexa is now available to any developer, enabling you to build sophisticated, natural language chatbots into your new and existing applications. Amazon Lex provides the deep functionality and flexibility of natural language understanding (NLU) and automatic speech recognition (ASR) so you can build highly engaging user experiences with lifelike, conversational interactions, and create new categories of products.
Amazon Lex enables any developer to build conversational chatbots quickly. With Amazon Lex, no deep learning expertise is necessary—to create a bot, you just specify the basic conversation flow in the Amazon Lex console. Amazon Lex manages the dialogue and dynamically adjusts the responses in the conversation. Using the console, you can build, test, and publish your text or voice chatbot. You can then add the conversational interfaces to bots on mobile devices, web applications, and chat platforms (for example, Facebook Messenger).
Amazon Lex provides pre-built integration with AWS Lambda, and you can easily integrate with many other services on the AWS platform, including Amazon Cognito, AWS Mobile Hub, Amazon CloudWatch, and Amazon DynamoDB. Integration with Lambda provides bots access to pre-built serverless enterprise connectors to link to data in SaaS applications, such as Salesforce, HubSpot, or Marketo.
Some of the benefits of using Amazon Lex include:
- Simplicity – Amazon Lex guides you through using the console to create your own chatbot in minutes. You supply just a few example phrases, and Amazon Lex builds a complete natural language model through which the bot can interact using voice and text to ask questions, get answers, and complete sophisticated tasks.
- Democratized deep learning technologies – Powered by the same technology as Alexa, Amazon Lex provides ASR and NLU technologies to create a Speech Language Understanding (SLU) system. Through SLU, Amazon Lex takes natural language speech and text input, understands the intent behind the input, and fulfills the user intent by invoking the appropriate business function.Speech recognition and natural language understanding are some of the most challenging problems to solve in computer science, requiring sophisticated deep learning algorithms to be trained on massive amounts of data and infrastructure. Amazon Lex puts deep learning technologies within reach of all developers, powered by the same technology as Alexa. Amazon Lex chatbots convert incoming speech to text and understand the user intent to generate an intelligent response, so you can focus on building your bots with differentiated value-add for your customers, to define entirely new categories of products made possible through conversational interfaces.
- Seamless deployment and scaling – With Amazon Lex, you can build, test, and deploy your chatbots directly from the Amazon Lex console. Amazon Lex enables you to easily publish your voice or text chatbots for use on mobile devices, web apps, and chat services (for example, Facebook Messenger). Amazon Lex scales automatically so you don’t need to worry about provisioning hardware and managing infrastructure to power your bot experience.
- Built-in integration with the AWS platform – Amazon Lex has native interoperability with other AWS services, such as Amazon Cognito, AWS Lambda, Amazon CloudWatch, and AWS Mobile Hub. You can take advantage of the power of the AWS platform for security, monitoring, user authentication, business logic, storage, and mobile app development.
- Cost-effectiveness – With Amazon Lex, there are no upfront costs or minimum fees. You are charged only for the text or speech requests that are made. The pay-as-you-go pricing and the low cost per request make the service a cost-effective way to build conversational interfaces. With the Amazon Lex free tier, you can easily try Amazon Lex without any initial investment.
Are You a First-time User of Amazon Lex?
If you are a first-time user of Amazon Lex, we recommend that you read the following sections in order:
- Getting Started with Amazon Lex – In this section, you set up your account and test Amazon Lex.
- API Reference – This section provides additional examples that you can use to explore Amazon Lex.
Amazon Lex: How It Works
Amazon Lex enables you to build applications using a speech or text interface powered by the same technology that powers Amazon Alexa. Following are the typical steps you perform when working with Amazon Lex:
- Create a bot and configure it with one or more intents that you want to support. You add the configuration so that the bot is able to understand the user’s goal (intent), engage in conversation with the user to elicit information, and, after the user provides the necessary data, fulfill the user’s intent.
- Test the bot. You can use the test window client provided by the Amazon Lex console.
- Publish a version and create an alias.
- Deploy the bot. You can deploy the bot on platforms such as mobile applications or messaging platforms such as Facebook Messenger.
Before you get started, familiarize yourself with the following Amazon Lex core concepts and terminology:
- Bot – A bot performs automated tasks such as ordering a pizza, booking a hotel, ordering flowers, and so on. An Amazon Lex bot is powered by Automatic Speech Recognition (ASR) and Natural Language Understanding (NLU) capabilities, the same technology that powers Amazon Alexa.Amazon Lex bots can understand user input provided with text or speech and converse in the natural language. You can create Lambda functions and add them as code hook in your intent configuration to perform user data validation and fulfillment tasks.
- Intent – An intent represents an action that the user wants to perform. You create a bot to support one or more related intents. For example, you might create a bot that orders pizza and drinks. For each intent, you provide the following required information:
- Intent name– A descriptive name for the intent. For example,
- Sample utterances – How a user might convey the intent. For example, a user might say “Can I order a pizza please” or “I want to order a pizza”.
- How to fulfill the intent – How you want to fulfill the intent after the user provides the necessary information (for example, place order with a local pizza shop). We recommend that you create a Lambda function to fulfill the intent.You can optionally configure the intent so Amazon Lex simply returns the information back to the client application to do the necessary fulfillment.
In addition to custom intents such as ordering a pizza, Amazon Lex also provides built-in intents to quickly set up your bot. For more information, see Built-in Intents and Slot Types.
- Slot – An intent can require zero or more slots or parameters. You add slots as part of the intent configuration. At runtime, Amazon Lex prompts the user for specific slot values. The user must provide values for all required slots before Amazon Lex can fulfill the intent.For example, the intent
OrderPizza requires slots such as pizza size, crust type, and the number of pizzas. In the intent configuration, you add these slots. For each slot, you provide slot type and a prompt for Amazon Lex to send to the client to elicit data from the user. A user can reply with a slot value that includes additional words, such as “large pizza please” or “let’s stick with small.” Amazon Lex can still understand the intended slot value.
- Slot type – Each slot has a type. You can create your custom slot types or use built-in slot types. For example, you might create and use the following slot types for the
- Size – With enumeration values,
- Crust – With enumeration values and
Amazon Lex also provides built-in slot types. For example,
AMAZON.NUMBER is a built-in slot type that you can use for the number of pizzas ordered. For more information, see Built-in Intents and Slot Types.
The following topics provide additional information. We recommend that you review them in order and then explore the Getting Started with Amazon Lex exercises.
Source: What Is Amazon Lex? – Amazon Lex