GBrain is an MIT-licensed open-source retrieval layer for AI agents, described as behaving "like Postgres" and acting as a just-in-time "3 book librarian" to supply contextual information. Announced by @garrytan on 2026-06-15, the project claims thousands of current users and is hosted at github.com/garrytan/gbrain.
GBrain is positioned as a retrieval layer for AI agents "like Postgres," intended to serve as a just-in-time "3 book librarian" to provide timely context to agents.
I want GBrain to be the retrieval layer like Postgres for your agent. It's custom built to be the just-in-time 3 book librarian to give your AI agent wings.
It's MIT-licensed free open source with thousands of users using it today.
github.com/garrytan/gbrain