Karpathys LLM wiki with QMD.
I have a small gatekeeper.py script the agent has to run to complete a round or begin a new one. One of the things it does (in addition to record keeping, linting, etc) is validate that the wiki has been updated with all the findings, lessons learned, and documentation for the round. The agent can't proceed until it's done.
Then in the AGENTS.md they're told they can use QMD to perform semantic search of the wiki , and should before starting any significant work.
It's expensive, in terms of tokens, but well worth it. I could reproduce any stage of my project if I wanted. I always know why they did what they did (if they do), and the agent's can't really forget anything important.