This is not one of the six document formats. Those are views over a document you keep working on. An HTML document is a finished artefact — a snapshot, not a workspace.
How one gets created
Ask your agent:“Turn the Q3 channel numbers into a one-page HTML report I can send to the board.”Only a connected agent can create one — there is no new-HTML-document button and no editor for them in the app. To change one, ask your agent again and it replaces the page. Tatara checks every HTML document as it is written and tells the agent what to fix if anything is wrong, so what lands in your brain is a page that renders. Pages are shown in a secure sandbox that runs no code and makes no outside requests, which means an HTML document in your brain can never phone home or run something unexpected when you open it.
How it renders
An HTML document is read-only. It fills the reading area edge to edge, with no title heading, no width control, and no editor. Two actions sit in the topbar:Open raw in new tabopens the page on its own.Expandgives it the full window.
File card at the top showing the filename, the line embedded · static html · no scripts · sandboxed, and an Open raw ↗ link.
If it looks wrong
If the page looks broken or empty, or showsCouldn't load HTML content., ask your agent to rebuild it — that is the fix, and it knows the rules it has to meet. See Troubleshooting.