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.
Audit the vault for material that should not be in it: credentials, other people's private information, confidential work, and anything the user would not want synced or backed up.
Install Second Brain Privacy
$ npx skills add undefined-ui/second-brain-os --skill second-brain-privacy -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-privacy --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/undefined-ui/second-brain-os.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/second-brain-privacy .claude/skills/second-brain-privacy && 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-privacy" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-privacy into .claude/skills/second-brain-privacy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-privacy", 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/undefined-ui/second-brain-os/tree/main/skills/second-brain-privacyType 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 undefined-ui/second-brain-os --skill second-brain-privacy -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-privacy --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/undefined-ui/second-brain-os.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/second-brain-privacy .agents/skills/second-brain-privacy && 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-privacy" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-privacy into .agents/skills/second-brain-privacy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-privacy", 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 undefined-ui/second-brain-os --skill second-brain-privacy -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-privacy --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/undefined-ui/second-brain-os.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/second-brain-privacy .cursor/skills/second-brain-privacy && 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-privacy" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-privacy into .cursor/skills/second-brain-privacy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-privacy", 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/undefined-ui/second-brain-os.git --path skills/second-brain-privacy--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 undefined-ui/second-brain-os --skill second-brain-privacy -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-privacy --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/undefined-ui/second-brain-os.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/second-brain-privacy .gemini/skills/second-brain-privacy && 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-privacy" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-privacy into .gemini/skills/second-brain-privacy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-privacy", 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 undefined-ui/second-brain-os second-brain-privacyInstalls 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 undefined-ui/second-brain-os --skill second-brain-privacy -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/undefined-ui/second-brain-os.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/second-brain-privacy .github/skills/second-brain-privacy && 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-privacy" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-privacy into .github/skills/second-brain-privacy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-privacy", 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 undefined-ui/second-brain-os --skill second-brain-privacy -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-privacy --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/undefined-ui/second-brain-os.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/second-brain-privacy .opencode/skills/second-brain-privacy && 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-privacy" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-privacy into .opencode/skills/second-brain-privacy/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-privacy", 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-privacy- GitHub stars
- 999
- Token cost
- ~477 tokens
- SKILL.md length
- 177 words
- Files
- 1
- Skills in repo
- 23
- Repo updated
- First seen
- Licence
- MIT
At a glance
Audit the vault for material that should not be in it: credentials, other people's private information, confidential work, and anything the user would not want synced or backed up.
- Works in 5 steps: Scan for credentials: API keys, tokens,… → Find other people's information: meeting… → Find confidential work: material under… → …
- The user asks about privacy
- SKILL.md covers Core rule, Workflow, Output format and Calibration
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Second Brain Privacy is an agent skill from undefined-ui/second-brain-os. Audit the vault for material that should not be in it: credentials, other people's private information, confidential work, and anything the user would not want synced or backed up. Use this skill when the user asks about privacy, is about to share or sync the vault, has just imported chat history or meeting notes, or asks what is sensitive in their notes. Do NOT use to delete anything on your own, or as a substitute for the publishing check.
Its SKILL.md is about 480 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 and Meeting notes and agendas. The repository describes itself as: An AI second brain that maintains itself. Full guide, starter vault, agent skills and scripts for a self-organizing knowledge base in Claude Code and Obsidian. The licence is MIT.
When your agent uses it
- The user asks about privacy
- Is about to share
- Has just imported chat history
- Asks what is sensitive in their notes
Example prompts
- “/second-brain-privacy”
Workflow steps
5 steps, taken from the first numbered list in SKILL.md.
- Scan for credentials: API keys, tokens, passwords, connection strings.
- Find other people's information: meeting transcripts, personal messages,
- Find confidential work: material under NDA or employer restriction.
- Check the git remote. Private material in a public repo is the most
- Report by severity, with the specific file and why.
What it can do on your machine
Read from SKILL.md and the folder at commit d6861cc. 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.
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 Privacy loads about 477 tokens when it runs. Until then it costs about 117 tokens; SKILL.md has 177 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
The full file from undefined-ui/second-brain-os at commit d6861cc, republished under its MIT licence (© undefined-ui). 177 words, ~477 tokens.
Download SKILL.mdSave it as
.claude/skills/second-brain-privacy/SKILL.md (or your agent's skills folder).- name
- second-brain-privacy
- description
- Audit the vault for material that should not be in it: credentials, other people's private information, confidential work, and anything the user would not want synced or backed up. Use this skill when the user asks about privacy, is about to share or sync the vault, has just imported chat history or meeting notes, or asks what is sensitive in their notes. Do NOT use to delete anything on your own, or as a substitute for the publishing check.
Audit privacy
A mature vault is one of the highest-signal documents about a person that exists, and it lives in a folder that gets synced, committed, backed up and occasionally shared. Every copy is another place the content exists.
Core rule
Find and report. Delete nothing without an explicit instruction naming what to remove.
Workflow
- Scan for credentials: API keys, tokens, passwords, connection strings.
Check
.obsidian/plugins/too, where plugin data lives. - Find other people's information: meeting transcripts, personal messages, anything told in confidence, health or financial detail about someone else.
- Find confidential work: material under NDA or employer restriction.
- Check the git remote. Private material in a public repo is the most expensive version of this problem.
- Report by severity, with the specific file and why.
Output format
Critical: <credentials, must be removed and rotated>
High: <other people's private information>
Review: <material the user should decide about>
Repo visibility: <public | private> - <verdict>Calibration
Never quote the credential itself in the report. Name the file and the type.
Redaction after ingest is unreliable, because material has already propagated into concept pages and links. When something should not be there, say what else would need removing with it.
© undefined-ui, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in skills/second-brain-privacy of undefined-ui/second-brain-os.
Open the folder on GitHubat commit d6861cc
Compare with similar skills
Second Brain Privacy 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 Privacy this skillundefined-ui/second-brain-os | 999 | — | ~477 | Automated safety check: Pass | MIT | |
| Obsidian Canvas BoardsAgriciDaniel/claude-obsidian | 15k | — | ~1.4k | Automated safety check: Pass | MIT | |
| 3D Brainnateherkai/AIS-OS | 1.6k | — | ~2.1k | Automated safety check: Pass | Custom licence | |
| Icm ArchitectRinDig/icm-architect | 1.8k | — | ~3.2k | Automated safety check: Pass | MIT | |
| Second BrainNicholasSpisak/second-brain | 735 | — | ~1.5k | Automated safety check: Notes | None | |
| Cascading Goal Trackerballred/obsidian-claude-pkm | 1.9k | — | ~1.5k | Automated safety check: Pass | MIT |
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Set up a new Obsidian knowledge base with the LLM Wiki pattern.
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More from undefined-ui/second-brain-os
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Audit an agent's context layout against the four places: system prompt, tools, history, tail.
Evals Bootstrap
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Scaffold a first eval suite for an agent: mine real failures into cases, write behavioural checks over traces, and generate the runner.
Gate Check
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Find the decisions in a pipeline that do not need the expensive model and propose the gate for each: a rule, a classic classifier, or a small model, with fail-closed routing.
Goal Test
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Turn a vague task into a testable definition of done and generate an executable goal-test script for it, optionally with a bounded retry loop around a headless agent.
Harness Audit
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Audit an agent's harness against the four rings: containment, guides, sensors, permissions.
Second Brain Chat Import
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Triage an exported chat history into what to ingest, what to archive and what to delete, with a privacy pass first.
Related
Categories
Questions about Second Brain Privacy
What does Second Brain Privacy do?
Audit the vault for material that should not be in it: credentials, other people's private information, confidential work, and anything the user would not want synced or backed up. Second Brain Privacy is an agent skill from undefined-ui/second-brain-os. Audit the vault for material that should not be in it: credentials, other people's private information, confidential work, and anything the user would not want synced or backed up.
When should I use Second Brain Privacy?
Second Brain Privacy fits situations like: the user asks about privacy; is about to share; has just imported chat history; asks what is sensitive in their notes.
How do I install Second Brain Privacy in Claude Code?
Run `npx skills add undefined-ui/second-brain-os --skill second-brain-privacy -a claude-code`. Or copy the skill folder (skills/second-brain-privacy in undefined-ui/second-brain-os) into .claude/skills/second-brain-privacy in your project. Claude Code loads it when a task matches its description.
How do I install Second Brain Privacy in Codex?
Run `npx skills add undefined-ui/second-brain-os --skill second-brain-privacy -a codex`. Or copy the skill folder (skills/second-brain-privacy in undefined-ui/second-brain-os) into .agents/skills/second-brain-privacy in your project. Codex loads it when a task matches its description.
Can I use Second Brain Privacy 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 undefined-ui/second-brain-os --skill second-brain-privacy -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-privacy, .gemini/skills/second-brain-privacy, .github/skills/second-brain-privacy and .opencode/skills/second-brain-privacy in your project.
What does Second Brain Privacy need to run?
SKILL.md names no scripts, command-line tools or credentials: Second Brain Privacy is instructions for the agent only.
Does Second Brain Privacy 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 Privacy 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 Privacy use?
Second Brain Privacy is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Second Brain Privacy use?
About 477 tokens (SKILL.md is roughly 1.9k 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 Privacy?
Skills that share tags, products or a category with Second Brain Privacy: Obsidian Canvas Boards (AgriciDaniel/claude-obsidian, 15k stars), 3D Brain (nateherkai/AIS-OS, 1.6k stars), Icm Architect (RinDig/icm-architect, 1.8k stars) and Second Brain (NicholasSpisak/second-brain, 735 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Second Brain Privacy?
undefined-ui (a GitHub user) maintains it in undefined-ui/second-brain-os, which has 999 GitHub stars. The repository holds 23 skills in this directory. The repository was last updated on September 29, 2026.
Source: undefined-ui/second-brain-os on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.