Daily's new Prebuilt Integrations API allows developers to easily embed third-party services into their Daily-powered video applications with just a few lines of code. The API provides a flexible way to integrate various services, such as Miro virtual whiteboards and CometChat chat widgets, into Daily calls. The API can be used to enable integrations before or after the user joins a call, and it supports custom tray buttons and sidebar views. Developers can use the API's `customIntegrations` property to configure integrations with specific settings, such as icon URLs, labels, and locations. The API also provides a way to set up custom button handlers for integration toggling, allowing developers to create unique experiences within their Daily-powered video applications.