The post provides a detailed guide on building a custom in-app feed modeled after Notion's interface using the Knock JavaScript client, Next.js, and shadcn/ui. It walks through configuring an in-app channel and workflow in Knock, fetching and updating a user's feed through the Feed API, and managing message engagement statuses like read and archived. The project emphasizes creating a tabbed feed interface, allowing users to switch views and interact with feed items, with functionalities such as marking all items as read or archived. The guide also highlights aesthetic elements from Notion's feed, such as opacity treatments for read items and a "New" icon for unread items, enhancing user experience. The example project is available on Knock's GitHub, and the post encourages developers to explore the flexibility of Knock's tools by signing up for free.