second-brain

second-brain is a cursor rule for Cursor from kidboy-man/vibe-engineering. It costs 442 tokens per session, scanned A, original, no licence file.

Guidance for maintaining a second-brain vault, a personal system for storing and finding notes, together with qmd MCP instructions.

In plain words
What is it for?
Use it when storing, retrieving, or managing knowledge in a second-brain vault. The description does not provide more specific workflows.
Why use it?
It helps organize persistent notes and explains how the qmd MCP connection should be used.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc).

Good fit Use it when storing, retrieving, or managing knowledge in a second-brain vault. The description does not provide more specific workflows.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/kidboy-man/vibe-engineering/second-brain
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.

Clone the repo
git clone --depth 1 https://github.com/kidboy-man/vibe-engineering

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for second-brain

README.md
[![agentmods](https://agentmods.dev/badge/rules/kidboy-man/vibe-engineering/second-brain/github.svg)](https://agentmods.dev/rules/kidboy-man/vibe-engineering/second-brain)
Your own site
<a href="https://agentmods.dev/rules/kidboy-man/vibe-engineering/second-brain"><img src="https://agentmods.dev/badge/rules/kidboy-man/vibe-engineering/second-brain/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for second-brain

Your own site · 80×15
<a href="https://agentmods.dev/rules/kidboy-man/vibe-engineering/second-brain"><img src="https://agentmods.dev/badge/rules/kidboy-man/vibe-engineering/second-brain.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 442 This file is loaded in full into every session.
When invoked 442 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00442 $0.00442
Opus 5.5 $0.00177 $0.00177
Sonnet 5.5 $0.00088 $0.00088
Haiku 4.5 $0.00044 $0.00044

Measured 1mo ago against content hash 7f2dff327405, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

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 1mo 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.

agents/kits/second_brain/templates/second_brain/rules/second-brain.mdc · 39 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 1mo ago First seen · 39 lines · 442 tokens per session scan A 7f2dff327405

Subscribe to this mod's changes

second-brain is a cursor rule published in the GitHub repository kidboy-man/vibe-engineering (2 stars, last pushed 2d ago), with no licence file. It adds 442 tokens to every session, about $0.0018 per session on Opus 5.5. 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.