Documind answers questions against PDFs you upload, and will build a chatbot trained on a whole collection rather than a single file. Working across a document set is the part that matters: most of the useful questions about a contract, a manual or a research folder span several files at once.
It also summarises, which covers the common case of needing the shape of a long document before deciding whether to read it.
There is a free trial. Answers still want checking against the source, since a confident citation of the wrong passage looks identical to a correct one, and scanned or badly structured PDFs extract poorly no matter which tool reads them.
