A plugin that provides a reviewable Markdown-based second brain for Codex and Claude Code. A second brain is an external collection of notes and knowledge used to support work.

Use it to organize notes and reusable knowledge while working with Codex or Claude Code.

It offers a place to keep project knowledge in readable files that people can inspect and review.

yarbrain — Plugin by yarlson

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code

/plugin marketplace add yarlson/yarstack

agentmods

npx agentmods add plugins/yarlson/yarstack/yarbrain

Clone the repo

git clone --depth 1 https://github.com/yarlson/yarstack

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.

When invoked not measured Not applicable: nothing here is loaded into a session.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Security

Grade A, and why

yarbrain scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

yarstack — 95% identical, 11 lines differ

plugins/yarbrain/.claude-plugin/plugin.json · 21 lines

What it actually says

{
  "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
  "name": "yarbrain",
  "displayName": "Yarbrain",
  "version": "0.2.0",
  "description": "A reviewable Markdown second brain for Codex and Claude Code.",
  "author": {
    "name": "Yar Kravtsov",
    "url": "https://github.com/yarlson"
  },
  "homepage": "https://github.com/yarlson/yarstack",
  "repository": "https://github.com/yarlson/yarstack",
  "license": "MIT",
  "keywords": [
    "codex",
    "claude-code",
    "memory",
    "knowledge-management"
  ]
}

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

yesterday First seen · 21 lines scan A 06c8d475d460

Subscribe to this mod's changes

yarbrain is a plugin published in the GitHub repository yarlson/yarstack (3 stars, last pushed 4d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Code review Productivity agent-skills agent-workflows ai-coding coding-agents developer-tools

yarbrain

Getting it into your agent

Grade A, and why

Nothing flagged

Copies of this mod

What it actually says

What this file has done since we first saw it

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