This post discusses how to add a text chat feature to a custom React video application using Daily's real-time video and audio APIs and the new custom React hooks library, Daily React Hooks. The goal is to allow participants to send and receive messages during a call. The app will have a toggleable chat UI, notifications when a new message is received by a participant who doesn't have the chat open, and the ability for new participants to read older messages after joining the meeting. The chat feature includes a form where users can input their messages, which are then broadcasted to other participants on the call using the `useAppMessage()` hook from Daily React Hooks. The app's state is managed using React hooks, such as `useState` and `useCallback`. The post assumes that the reader has basic knowledge of React and JavaScript.