How do I install the Second Brain Ingest skill?

Run npx skillmds@latest add undefined-ui/second-brain-ingest in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Second Brain Ingest safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Second Brain Ingest?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Second Brain Ingest free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Second Brain Ingest?

undefined-ui (@undefined-ui) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Second Brain Ingest by undefined-ui

Name: Second Brain Ingest
Author: undefined-ui

Second Brain Ingest

Turn raw source material in a second-brain vault into linked wiki pages: read the source, split it into concepts and entities, write or update pages, connect them to existing pages, and record the run in the log. Use this skill whenever the user drops a file into raw/, pastes an article, transcript or PDF and asks to add it to the vault, says "ingest this", "add this to my second brain", "process raw", or asks to catch up on unprocessed sources, even if they do not name the ingest command. Do NOT use for answering questions from an existing vault, for linting or repairing pages, or for editing notes the user wrote by hand.

undefined-ui e7c59f0 3.4 KB Updated Sep 17, 2026

File contents

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

Read the source completely before writing anything. Partial reads produce pages built from the introduction, which is where sources are least specific.
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.
Write the source page in wiki/sources/. Record claims as claims, with the source attached.
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.
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.
Update index.md and append to log.md in the same run, because an index that lags is how a vault starts drifting.
Report what changed.

Output format

End every run with this exact shape:

Ingested: <source name>
New pages: <n> (list)
Updated pages: <n> (list)
Links added: <n>
Contradictions found: <none | description>
Gaps created: <list of linked pages that do not exist yet>

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.

---name: second-brain-ingestdescription: Turn raw source material in a second-brain vault into linked wiki pages: read the source, split it into concepts and entities, write or update pages, connect them to existing pages, and record the run in the log. Use this skill whenever the user drops a file into raw/, pastes an article, transcript or PDF and asks to add it to the vault, says "ingest this", "add this to my second brain", "process raw", or asks to catch up on unprocessed sources, even if they do not name the ingest command. Do NOT use for answering questions from an existing vault, for linting or repairing pages, or for editing notes the user wrote by hand.---# Ingest a sourceAn ingest that only writes a summary page produces a vault that grows withoutgetting smarter. The whole value is in the second half of the job: connectingthe new material to what is already there. A page that lands unlinked isinvisible within a week.## Core ruleNothing is ingested until it is linked. Every run ends with the new pagesconnected to existing pages in both directions.## Workflow1. **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 formatEnd every run with this exact shape:```Ingested: <source name>New pages: <n> (list)Updated pages: <n> (list)Links added: <n>Contradictions found: <none | description>Gaps created: <list of linked pages that do not exist yet>```## CalibrationOver-extraction is the common failure: ten thin concept pages from one article,each a restated paragraph. A source usually yields one to three concepts worththeir own page. If a candidate concept cannot be explained without referringback to this one source, it belongs inside the source page instead.Under-extraction shows up as source pages that contain three separate ideas andlink to nothing. If a page needs section headings for unrelated topics, splitit.## ExampleInput: the user drops `raw/karpathy-llm-wiki.md`, a clipped gist, into a vaultthat already has pages for `[[Obsidian]]` and `[[Claude Code]]`.Output: one source page; a new concept page `[[LLM wiki]]` explaining thepattern in plain language; an entity page `[[Andrej Karpathy]]`; updates to`[[Obsidian]]` and `[[Claude Code]]` noting their role in the pattern; a linkfrom the existing `[[Personal knowledge management]]` concept to the new one;index and log updated; report showing 3 new, 3 updated, 11 links.

Frequently asked questions