second-brain

A plugin for organising personal knowledge as connected, small notes that an AI can extract, link, inspect, and revise.

In plain words
What is it for?
Use it to extract claims, connect and walk through notes, audit or learn from them, initialise or refine the collection, and optionally teach or surrender control.
Why use it?
It provides named operations for maintaining a flat notes folder without hidden queues or multi-step workflow machinery.

Plugin for Claude Code

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 letrplB/second-brain
agentmods
npx agentmods add plugins/letrplb/second-brain/marketplace
Clone the repo
git clone --depth 1 https://github.com/letrplB/second-brain

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

second-brain 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.

.claude-plugin/marketplace.json · 34 lines

What it actually says

{
  "$schema": "https://anthropic.com/claude-code/marketplace.schema.json",
  "name": "second-brain",
  "owner": {
    "name": "bastian beitzinger"
  },
  "metadata": {
    "description": "Personal knowledge graph plugin: atomic claims, walked natively by LLMs as semantic engines.",
    "version": "0.1.0"
  },
  "plugins": [
    {
      "name": "second-brain",
      "description": "Eight core verbs over a flat notes folder — extract, connect, walk, audit, learn, init, anneal, dream — plus an opt-in surrender system (no-surrender, teach). No queues, no phase machines, no invisible hooks.",
      "version": "0.1.0",
      "source": "./",
      "strict": false,
      "author": {
        "name": "bastian beitzinger"
      },
      "license": "MIT",
      "keywords": [
        "knowledge-management",
        "tools-for-thought",
        "knowledge-graph",
        "second-brain",
        "atomic-notes",
        "agent-native"
      ],
      "category": "productivity"
    }
  ]
}
Files

What ships with it

1 file beside marketplace.json in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

  1. yesterday First seen · 34 lines scan A 5a6388d8a3c7

Subscribe to this mod's changes

second-brain is a plugin published in the GitHub repository letrplB/second-brain (1 stars, last pushed 3mo 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.