second-brain-query — Claude Code skill: answers from your wiki
This skill searches your knowledge base wiki and answers questions with citations back to the pages it used. Handy once your notes outgrow your memory.
npx skills add NicholasSpisak/second-brain --skill second-brain-query -a claude-codeWhat second-brain-query does
The skill answers questions against a wiki knowledge base. It starts by reading wiki/index.md and scanning the Sources, Entities, Concepts and Synthesis sections for pages that match the question. Then it reads those pages and follows [[wikilinks]] for related context. If the pages fall short, it checks summaries in wiki/sources/; files in raw/ are the last resort.
Large wikis get a faster path. When qmd is installed (check with command -v qmd), search runs through qmd search "query terms" --path wiki/. The author suggests switching to it once the wiki passes roughly 100 pages and scanning the index stops being practical. Answer format follows the question: a direct answer with citations, a table for comparisons, a narrative for exploration. Every claim links to a wiki page via [[wikilink]], never to a raw file path.
When an answer is worth keeping — a comparison, an analysis, a new connection — the skill offers to save it as a page in wiki/synthesis/, add an entry to the index and a line to wiki/log.md. That is the point: good answers stay in the base instead of disappearing into chat history. It pairs with /second-brain-ingest for pulling in new sources and /second-brain-lint for health-checking the wiki.
What it helps with
- find what you already wrote on a topic without scrolling the wiki
- get an answer with links to the pages it came from
- compare two topics using your own notes
- trace connections between concepts through
[[wikilinks]] - save a good analysis back into the wiki
Example prompts for the agent
- what do I know about vector databases?
- compare the caching approaches in my wiki
- search my wiki for notes on indexes and show the connections
How to install second-brain-query
1Skills CLI (Vercel)
npx skills add NicholasSpisak/second-brain --skill second-brain-query -a claude-code2Manually: put the files in place
~/.claude/skills/second-brain-query/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/second-brain-query/
1Skills CLI (Vercel)
npx skills add NicholasSpisak/second-brain --skill second-brain-query -a codex2Manually: put the files in place
.agents/skills/second-brain-query/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add NicholasSpisak/second-brain --skill second-brain-query -a cursor2Manually: put the files in place
.cursor/skills/second-brain-query/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install NicholasSpisak/second-brain second-brain-query2Manually: put the files in place
.github/skills/second-brain-query/SKILL.md1Skills CLI (Vercel)
npx skills add NicholasSpisak/second-brain --skill second-brain-query -a gemini-cli2Platform CLI
gemini skills install https://github.com/NicholasSpisak/second-brain --path skills/second-brain-queryManually: put the files in place
.devin/skills/second-brain-query/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add NicholasSpisak/second-brain --skill second-brain-query -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: How to install skills in Claude Code: five ways
Questions about second-brain-query
How do I install second-brain-query in Claude?
Run npx skills add NicholasSpisak/second-brain --skill second-brain-query -a claude-code. The skill lands in ~/.claude/skills/second-brain-query/SKILL.md.
What does second-brain-query do?
It answers questions against your wiki knowledge base: reads the index, the relevant pages and linked context, then writes an answer citing pages as [[wikilink]].
What do I need for the skill to work?
A wiki with a wiki/index.md file. For larger bases the author suggests installing qmd — the skill checks for it with command -v qmd and searches through qmd search.
