Historia queries public archives live on every search and hands the thinking back to the student. It cannot write the paper: the refusal is enforced by the server rather than by a prompt, and the output format has no field that can hold essay prose.
Archives queried live: the public APIs of the Library of Congress, Chronicling America, the US National Archives, the Smithsonian, DPLA, the Internet Archive, the UK National Archives, Gallica, the Wellcome Collection, the Met, the Art Institute of Chicago, Old Bailey Online, GovInfo, OpenAlex, Semantic Scholar and DOAJ.
No student accounts and no sign-in are required to search. Sources a student keeps are held in that student's own browser.