# Second Brain Ingest

> >-

- **Type:** Skill
- **Install:** `agentstack add skill-undefined-ui-second-brain-os-second-brain-ingest`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [undefined-ui](https://agentstack.voostack.com/s/undefined-ui)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [undefined-ui](https://github.com/undefined-ui)
- **Source:** https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-ingest
- **Website:** https://x.com/undefinedKi/status/2068306794116501544

## Install

```sh
agentstack add skill-undefined-ui-second-brain-os-second-brain-ingest
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Ingest a source

An ingest that only writes a summary page produces a vault that grows without
getting smarter. The whole value is in the second half of the job: connecting
the new material to what is already there. A page that lands unlinked is
invisible within a week.

## Core rule

Nothing is ingested until it is linked. Every run ends with the new pages
connected to existing pages in both directions.

## Workflow

1. **Read the source completely** before writing anything. Partial reads
   produce pages built from the introduction, which is where sources are least
   specific.
2. **Check what already exists.** Search the wiki for the main entities and
   concepts. Ingesting into an empty vault and ingesting into a vault of 300
   pages are different jobs: in the second, most of your work is updating
   pages, not creating them.
3. **Write the source page** in `wiki/sources/`. Record claims as claims, with
   the source attached.
4. **Extract concepts and entities.** One page per idea. If a concept page
   exists, add what this source contributes and update `updated:`. If it
   contradicts what is there, record both positions rather than replacing.
5. **Link in both directions.** The source page links to every concept and
   entity it touches; each of those links back. Add any missing target pages,
   or list them under Gaps in `index.md`.
6. **Update `index.md` and append to `log.md`** in the same run, because an
   index that lags is how a vault starts drifting.
7. **Report** what changed.

## Output format

End every run with this exact shape:

```
Ingested: 
New pages:  (list)
Updated pages:  (list)
Links added: 
Contradictions found: 
Gaps created: 
```

## Calibration

Over-extraction is the common failure: ten thin concept pages from one article,
each a restated paragraph. A source usually yields one to three concepts worth
their own page. If a candidate concept cannot be explained without referring
back to this one source, it belongs inside the source page instead.

Under-extraction shows up as source pages that contain three separate ideas and
link to nothing. If a page needs section headings for unrelated topics, split
it.

## Example

Input: the user drops `raw/karpathy-llm-wiki.md`, a clipped gist, into a vault
that already has pages for `[[Obsidian]]` and `[[Claude Code]]`.

Output: one source page; a new concept page `[[LLM wiki]]` explaining the
pattern in plain language; an entity page `[[Andrej Karpathy]]`; updates to
`[[Obsidian]]` and `[[Claude Code]]` noting their role in the pattern; a link
from the existing `[[Personal knowledge management]]` concept to the new one;
index and log updated; report showing 3 new, 3 updated, 11 links.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [undefined-ui](https://github.com/undefined-ui)
- **Source:** [undefined-ui/second-brain-os](https://github.com/undefined-ui/second-brain-os)
- **License:** MIT
- **Homepage:** https://x.com/undefinedKi/status/2068306794116501544

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-undefined-ui-second-brain-os-second-brain-ingest
- Seller: https://agentstack.voostack.com/s/undefined-ui
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.