# Eight open-source "second brain" repos for AI agent memory, including Garry Tan's gbrain

> Original title: this is f*cking insane.

- Source: X search: AI open-source releases
- Published: 2026-11-08T20:23:25.000Z
- Bad Influence: https://badinfluence.news/items/u6xznvzu06jq3ts20mq6pvajm
- Original: https://x.com/0x_rody/status/2119526223835529624

## Summary

A social post lists eight open-source "second brain" repositories for storing knowledge and sharing memory across AI agents. The list includes gbrain by Garry Tan, which the post says keeps source attribution for every fact and shares one memory across agents, and Andrej Karpathy's LLM wiki idea file. Other entries use plain markdown and Obsidian for memory handoff between Claude Code and Codex, voice notes in Telegram, and nightly conversion of repeated corrections into agent rules.

## Post

this is f*cking insane.

the ceo of y combinator open-sourced his own second brain and most people still don’t know it exists.

8 second brain repos you haven’t seen yet:

→ gbrain (by garrytan)  
http://github.com/garrytan/gbrain  
the second brain of the yc ceo. every fact keeps its source and every agent shares one memory.

→ llm wiki (by karpathy)  
http://gist.github.com/karpathy/442a6bf555914893e9891c11519de94f  
the original idea file behind all of this.

→ ai-memory (by akitaonrails)  
http://github.com/akitaonrails/ai-memory  
hand the work from claude code to codex without losing context. memory lives in plain markdown.

→ agent second brain (by smixs)  
http://github.com/smixs/agent-second-brain  
send a voice note in telegram and it lands as a linked note in your obsidian vault.

→ cog second brain (by huytieu)  
http://github.com/huytieu/COG-second-brain  
33 skills and 10 agents running on plain markdown, no database.

→ open second brain (by itechmeat)  
http://github.com/itechmeat/open-second-brain  
a nightly pass turns the corrections you keep repeating into rules your agent follows.

→ claude second brain (by jessepinkman9900)  
http://github.com/jessepinkman9900/claude-second-brain  
one npx command scaffolds obsidian, claude code and local search.

→ baalda (by naveedharri)  
http://github.com/naveedharri/baalda  
a team second brain where people and agents edit the same markdown files.

the ceo of y combinator runs his agents on this.  
you are still digging through bookmarks.

[Video](https://badinfluence.news/api/img-proxy?u=https%3A%2F%2Fpbs.twimg.com%2Famplify_video_thumb%2F2119526158333009920%2Fimg%2FOYjOy_6LErf9KVeJ.jpg&mode=thumb&exp=1794528000&sig=064145a4c6dc0ff4)

## Quoted post @0x_rody

> https://x.com/i/article/2117200906999717888

https://x.com/0x_rody/status/2117226304860819729