What is open-second-brain?

A plugin marketplace listing for Open Second Brain, a self-hosted knowledge system that stores information in Markdown files compatible with Obsidian. The listing describes one plugin and its available categories and tags.

Use it to publish or discover the Open Second Brain plugin for notes, agent skills, event logs, and external tool connections.

It gives an agent or marketplace a structured description of where to find and identify the plugin.

open-second-brain — Plugin by itechmeat

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 itechmeat/open-second-brain

agentmods

npx agentmods add plugins/itechmeat/open-second-brain/marketplace

Clone the repo

git clone --depth 1 https://github.com/itechmeat/open-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

open-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 2d ago.

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 · 21 lines

What it actually says

{
  "name": "open-second-brain",
  "owner": {
    "name": "itechmeat",
    "url": "https://github.com/itechmeat"
  },
  "metadata": {
    "description": "Open Second Brain marketplace (single self-hosted plugin).",
    "version": "1.0.0"
  },
  "plugins": [
    {
      "name": "open-second-brain",
      "source": "./",
      "description": "Plugin-first second brain for AI agents and humans (Obsidian-compatible Markdown vaults).",
      "category": "knowledge",
      "tags": ["second-brain", "obsidian", "agents", "skills", "event-log", "mcp"]
    }
  ]
}

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.

plugin.json 435 B

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.

2d ago First seen · 21 lines scan A da1c2914ba6b

Subscribe to this mod's changes

open-second-brain is a plugin published in the GitHub repository itechmeat/open-second-brain (378 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 2026-08-30.

Productivity

open-second-brain

Getting it into your agent

Grade A, and why

Nothing flagged

What it actually says

What ships with it

What this file has done since we first saw it

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