api.md, new in server/docs, documents the HTTP interface between the rss.chat client and its server — every read and write call, the no-passwords email flow, the item record field by field, and the websocket verbs. The client that ships with the product is just one user of this API; the doc is for whoever wants to build the next one.
Also in server/docs: install.md's "An AI can do this install" section moved to the end of the doc — it's a good trick, but not the first thing a new host-runner needs to read.