I built a tool for myself for this. It runs on localhost and uses sqlite as a storage engine for metadata, and the XDG paradigm for content (eg ~/.local/share, ~/.local/state) I create topics, eg localhost:8080/topic/1. Each topic can have tickets, artifacts and sessions. Tickets are linked task tracking tickets (eg Jira, though not actually Jira in my case), artifacts are documents etc produced during sessions, and sessions are Claude Code sessions (though it wouldn't have to be Claude, that's just what I use).

Sessions run in a terminal emulator in the browser. What makes this work is that I have some general purpose directions/context each topic gets, but there's also a running topic.md that gets updated at the end of each session. This way my context builds up and persists specific to that topic. Artifacts the agent produces (eg specs, plans) open up in a sidebar and render as HTML even though they're stored as markdown, and its easy to go back and find them from previous sessions. Session transcripts also are accessible from the Topic page.

I do regularly run compaction on the topic.md, moving the full content to an archive and keeping the working context smaller.