what it is
Garry Tan’s knowledge brain for agents, pitched as “the memex Vannevar Bush imagined, built for people who think for a living.” It indexes markdown repos into Postgres with pgvector and hybrid search, so an agent can search its memory instead of grepping files.
In April it was pitched for OpenClaw agents. You paste the install instructions into the agent and it does the rest. gstack now ships /setup-gbrain and /sync-gbrain skills that install the CLI, create a local PGLite or Supabase brain and register it as an MCP server for a coding agent.
what I found
One user’s numbers after six months, from Garry Tan’s post:
- 10,000+ markdown files indexed and searchable
- 3,000+ people with compiled dossiers and relationship history
- 13 years of calendar data, 21,000+ events
- 5,800+ Apple Notes going back to 2009