second-brain-query skillA
second-brain-query is agent-read markdown (skill) from undefined-ui/second-brain-os: 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 noth.
Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns 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
mdr add undefined-ui/second-brain-os/second-brain-query@git:20260907.8c47c65mdr add undefined-ui/second-brain-os/second-brain-query@sha256:42da21bc1c56d6f5Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.
[](https://markdownregistry.com/a/art_k6gooqqmx3kycgwg)
1 badge views in 30 days
Versions
Audit of the latest version
- 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
undefined-ui/second-brain-os · 296 stars · license MIT · pushed 2026-09-23 · 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 agent 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.