Second Brain
NicholasSpisak/second-brain
Set up a new Obsidian knowledge base with the LLM Wiki pattern.
Answer a natural-language question by synthesising content from wiki/, and save the response to outputs/.
Install Second Brain Query
$ npx skills add PieroSierra/SecondBrain --skill second-brain-query -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install PieroSierra/SecondBrain second-brain-query --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/PieroSierra/SecondBrain.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/second-brain-query .claude/skills/second-brain-query && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "second-brain-query" agent skill from https://github.com/PieroSierra/SecondBrain/tree/main/.claude/skills/second-brain-query into .claude/skills/second-brain-query/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-query", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/PieroSierra/SecondBrain/tree/main/.claude/skills/second-brain-queryType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add PieroSierra/SecondBrain --skill second-brain-query -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install PieroSierra/SecondBrain second-brain-query --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PieroSierra/SecondBrain.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/second-brain-query .agents/skills/second-brain-query && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "second-brain-query" agent skill from https://github.com/PieroSierra/SecondBrain/tree/main/.claude/skills/second-brain-query into .agents/skills/second-brain-query/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-query", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add PieroSierra/SecondBrain --skill second-brain-query -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install PieroSierra/SecondBrain second-brain-query --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PieroSierra/SecondBrain.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/second-brain-query .cursor/skills/second-brain-query && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "second-brain-query" agent skill from https://github.com/PieroSierra/SecondBrain/tree/main/.claude/skills/second-brain-query into .cursor/skills/second-brain-query/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-query", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/PieroSierra/SecondBrain.git --path .claude/skills/second-brain-query--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add PieroSierra/SecondBrain --skill second-brain-query -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install PieroSierra/SecondBrain second-brain-query --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PieroSierra/SecondBrain.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/second-brain-query .gemini/skills/second-brain-query && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "second-brain-query" agent skill from https://github.com/PieroSierra/SecondBrain/tree/main/.claude/skills/second-brain-query into .gemini/skills/second-brain-query/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-query", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install PieroSierra/SecondBrain second-brain-queryInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add PieroSierra/SecondBrain --skill second-brain-query -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/PieroSierra/SecondBrain.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/second-brain-query .github/skills/second-brain-query && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "second-brain-query" agent skill from https://github.com/PieroSierra/SecondBrain/tree/main/.claude/skills/second-brain-query into .github/skills/second-brain-query/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-query", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add PieroSierra/SecondBrain --skill second-brain-query -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install PieroSierra/SecondBrain second-brain-query --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/PieroSierra/SecondBrain.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/second-brain-query .opencode/skills/second-brain-query && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "second-brain-query" agent skill from https://github.com/PieroSierra/SecondBrain/tree/main/.claude/skills/second-brain-query into .opencode/skills/second-brain-query/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-query", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
second-brain-query- GitHub stars
- 152
- Token cost
- ~2.1k tokens
- SKILL.md length
- 1,056 words
- Files
- 1
- Skills in repo
- 15
- Repo updated
- First seen
- Licence
- None found
At a glance
Answer a natural-language question by synthesising content from wiki/, and save the response to outputs/.
- Works in 9 steps: Parse the question → Check preconditions → Read the index and identify relevant… → …
- Tasks that involve Second brain
- SKILL.md covers Invocation, Execution, Invariants and Error Conditions
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Second Brain Query is an agent skill from PieroSierra/SecondBrain. Answer a natural-language question by synthesising content from wiki/, and save the response to outputs/.
Its SKILL.md is about 2.1k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Knowledge Management, covering Second brain. The repository describes itself as: A personal knowledge base that lives in this folder. Drop content in, have it organized automatically, ask questions, and get sourced answers — either through Claude Code slash…
When your agent uses it
- Tasks that involve Second brain
Example prompts
- “/second-brain-query”
Workflow steps
9 steps, taken from the step headings in SKILL.md.
- Parse the question
- Check preconditions
- Read the index and identify relevant topics
- Read relevant wiki articles
- Synthesise the answer
- Generate the thread title
- Generate output filename
- Write the output file
- Display and confirm
What it can do on your machine
Read from SKILL.md and the folder at commit cdcf96f. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are markdown).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Second Brain Query loads about 2.1k tokens when it runs. Until then it costs about 31 tokens; SKILL.md has 1,056 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
Without a licence we can't republish the file, so here is its outline and opening line. It has 1,056 words (~2,117 tokens).
“Answer a natural-language question by synthesising content from wiki/, and save the response to outputs/.”
- name
- second-brain-query
- argument-hint
- [--image "<path>"]... "<question>"
- user-invocable
- true
Files
Just SKILL.md in .claude/skills/second-brain-query of PieroSierra/SecondBrain.
Open the folder on GitHubat commit cdcf96f
Compare with similar skills
Second Brain Query next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Second Brain Query this skillPieroSierra/SecondBrain | 152 | — | ~2.1k | Automated safety check: Pass | None | |
| Second BrainNicholasSpisak/second-brain | 736 | 1 repos | ~1.5k | Automated safety check: Notes | None | |
| 3D Brainnateherkai/AIS-OS | 1.6k | — | ~2.1k | Automated safety check: Pass | Custom licence | |
| Obsidian Canvas BoardsAgriciDaniel/claude-obsidian | 15k | — | ~1.4k | Automated safety check: Pass | MIT | |
| Icm ArchitectRinDig/icm-architect | 1.8k | — | ~3.2k | Automated safety check: Pass | MIT | |
| Obsidian CLI Read TransportAgriciDaniel/claude-obsidian | 15k | 1 repos | ~762 | Automated safety check: Pass | MIT |
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nateherkai/AIS-OS
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Obsidian Canvas Boards
AgriciDaniel/claude-obsidian
Creates, inspects and updates Obsidian JSON Canvas boards in a vault, with text, file, link, group and edge nodes, using safe recoverable edits.
Icm Architect
RinDig/icm-architect
Design any process, idea, problem, or body of knowledge into an ICM (Interpretable Context Methodology) workspace — folder structure as agent architecture — or restructure an existing folder, repo…
Obsidian CLI Read Transport
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Detects and uses the official Obsidian command-line interface for read-only vault access, falling back to direct file reads, while all mutations stay on a separate transaction core.
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More from PieroSierra/SecondBrain
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Work through open findings in the latest lint report one at a time — propose a fix, apply on approval, skip on rejection.
Second Brain Describe Images
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Describe one or more images pasted with a note and return the descriptions as JSON.
Second Brain Edit Wiki
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Apply targeted edits to one or more wiki articles from a natural-language instruction, preserving structural invariants.
Second Brain Follow Up
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Continue an existing conversation thread by re-reading the wiki and appending a follow-up answer to the thread file.
Second Brain Import Craft
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Import a specific document from your configured Craft space into raw/craft/.
Second Brain Import File
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Import a file of any supported type (PDF, image, .txt/.md) into the vault's raw/ directory, ready for ingestion.
Related
Categories
Questions about Second Brain Query
What does Second Brain Query do?
Answer a natural-language question by synthesising content from wiki/, and save the response to outputs/. Second Brain Query is an agent skill from PieroSierra/SecondBrain. Answer a natural-language question by synthesising content from wiki/, and save the response to outputs/.
When should I use Second Brain Query?
Second Brain Query fits situations like: tasks that involve Second brain.
How do I install Second Brain Query in Claude Code?
Run `npx skills add PieroSierra/SecondBrain --skill second-brain-query -a claude-code`. Or copy the skill folder (.claude/skills/second-brain-query in PieroSierra/SecondBrain) into .claude/skills/second-brain-query in your project. Claude Code loads it when a task matches its description.
How do I install Second Brain Query in Codex?
Run `npx skills add PieroSierra/SecondBrain --skill second-brain-query -a codex`. Or copy the skill folder (.claude/skills/second-brain-query in PieroSierra/SecondBrain) into .agents/skills/second-brain-query in your project. Codex loads it when a task matches its description.
Can I use Second Brain Query in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add PieroSierra/SecondBrain --skill second-brain-query -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/second-brain-query, .gemini/skills/second-brain-query, .github/skills/second-brain-query and .opencode/skills/second-brain-query in your project.
What does Second Brain Query need to run?
SKILL.md names no scripts, command-line tools or credentials: Second Brain Query is instructions for the agent only.
Does Second Brain Query access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Second Brain Query safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Second Brain Query use?
No licence was found for Second Brain Query or its repository. Without one, default copyright applies: ask the author before reusing or redistributing it.
How many tokens does Second Brain Query use?
About 2.1k tokens (SKILL.md is roughly 8.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Second Brain Query?
Skills that share tags, products or a category with Second Brain Query: Second Brain (NicholasSpisak/second-brain, 736 stars), 3D Brain (nateherkai/AIS-OS, 1.6k stars), Obsidian Canvas Boards (AgriciDaniel/claude-obsidian, 15k stars) and Icm Architect (RinDig/icm-architect, 1.8k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Second Brain Query?
PieroSierra (a GitHub user) maintains it in PieroSierra/SecondBrain, which has 152 GitHub stars. The repository holds 15 skills in this directory. The repository was last updated on October 5, 2026.
Source: PieroSierra/SecondBrain on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.