Unsay

Agent memory that goes back and corrects the answers it already gave.

2nd place, CockroachDB × AWS Hackathon: Build with Agentic Memory. Judged across 3,700 participants. The entry is still public, and so is everything it was built from.
The live demo is retired. It ran on a CockroachDB Cloud cluster that was torn down when judging closed, because leaving a paid database running past a hackathon is how you get a surprise bill. Everything below still works, and the repository rebuilds the whole thing from scratch against live openFDA data.