How to build a real-time chat application with Momento: a step-by-step guide

This guide provides a comprehensive walkthrough on building a real-time chat application using Momento Topics, which helps manage user connections efficiently by charging only for usage rather than idle connection time. Users need a Momento and AWS account, Node.js, and CDK v2 to get started, and the guide highlights creating a virtual topic with Momento Topics without explicit topic creation. Authentication and authorization are managed using API keys and disposable tokens, allowing controlled access to chat rooms. The architecture involves a full-stack application where chat rooms are stored in DynamoDB, and users can create or join rooms, with messages being published to associated Momento topics. The guide details setting up APIs with AWS Lambda, API Gateway, and Cognito for secure communication, emphasizing the secure handling of API keys with AWS Systems Manager Parameter Store. It also discusses deploying ephemeral environments for isolated development and testing, and the process of subscribing to topics and sending messages in the frontend using a subscription object to ensure real-time messaging. The guide concludes with instructions on deploying and testing the application, encouraging users to explore further through a linked course for more insights into building real-time applications with Momento.