Musuw

Musuw is a research workspace that builds a knowledge base from your own material and answers questions against it with evidence. You define the sources, and it retrieves across them, compares them and synthesizes an answer while showing which source supports which claim, so every conclusion can be checked rather than taken on trust. Over time it organizes the material into a connected structure and surfaces relationships between documents. The free plan is permanent but small: 1 GiB of storage and one knowledge base of 10 documents on standard models. Plus costs $5 a month for 10 GiB, unlimited knowledge bases, advanced models and video and link import, with Pro at $10 and Max at $20 adding storage. It can only be as good as the sources you give it.