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second-brain-query SKILL.md skillA

second-brain-query from undefined-ui/second-brain-os is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add undefined-ui/second-brain-os/second-brain-query@git:20260907.8c47c65

Pins git:20260907.8c47c65 in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: undefined-ui/second-brain-os
Path: skills/second-brain-query/SKILL.md
Versions recorded: 1
Latest version: git:20260907.8c47c65, committed Sep 7, 2026
Size: 2,199 bytes
Repository stars: 1,499
License: MIT

Answer a question from a second-brain vault by reading its own pages, citing the pages used, and saying plainly when the vault does not contain the answer. Use this skill whenever the user asks what they know about a topic, what they have read on something, what connects two ideas, what they have changed their mind about, or asks any question that should be answered from their own notes rather than general knowledge. Do NOT use for ingesting new material, for general questions the vault has…

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# Query the vault

A query that quietly falls back on general knowledge is the most damaging thing
this system can do. The owner built the vault so answers would be grounded in
what they actually read, and an answer that blends the model's priors with
their notes is worse than no answer, because it cannot be checked.

## Core rule

Every claim in the answer comes from a page in the vault and names that page.
Anything you know but the vault does not is labelled as outside knowledge or
left out.

## Workflow

1. **Start from `index.md`**, not from a full-text sweep. The index is the map;
   reading it first keeps the context budget for actual pages.
2. **Follow links outward** from the most relevant pages, one hop at a time.
   Stop when new pages stop adding anything.
3. **Answer in plain language**, with `[[page]]` references inline.
4. **Name the gaps.** If the question has three parts and the vault covers two,
   say which one it does not.
5. **Offer the next move** when there is an obvious one: a source worth
   ingesting, a synthesis page worth writing.

## Output format

Plain prose, then:

```
Read: <pages consulted>
Not covered: <what the vault does not answer>
```
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add undefined-ui/second-brain-os/second-brain-query@sha256:42da21bc1c56d6f5

The line at the top of this page pins the label git:20260907.8c47c65, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

[![mdr](https://markdownregistry.com/badge/art_k6gooqqmx3kycgwg.svg)](https://markdownregistry.com/a/art_k6gooqqmx3kycgwg)

4 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 1 version of this file, committed on Sep 7, 2026.

version	committed	commit	size	audit
git:20260907.8c47c65 latest	2026-09-07	8c47c65	2,199 B	A	view

Audit of the latest version

A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (2199 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag

Source

GitHub

undefined-ui/second-brain-os · 1,499 stars · license MIT · pushed 2026-11-03 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_k6gooqqmx3kycgwg
GET https://markdownregistry.com/api/v1/resolve?ref=undefined-ui/second-brain-os/second-brain-query
GET https://markdownregistry.com/api/v1/blob/42da21bc1c56d6f52e5f323fec2bd0f7743bd111206773e1e8251cc2da45a374

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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