**The `Document` extension is required**, no matter what you build with tiptap. It’s a so called “topNode”, a node that’s the home to all other nodes. Think of it like the `<body>` tag for your document.
The node is very tiny though. It defines a name of the node (`doc`), is configured to be a top node (`topNode: true`) and that it can contain multiple other nodes (`block+`). That’s all. But have a look yourself: