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.
Analyse the vault's link graph and report on its shape: orphan rate, average degree, components, hubs, bridges and clusters, with what each number means for retrieval.
Install Second Brain Graph
$ npx skills add undefined-ui/second-brain-os --skill second-brain-graph -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-graph --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-graph .claude/skills/second-brain-graph && 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-graph" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-graph into .claude/skills/second-brain-graph/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-graph", 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-graphType 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-graph -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-graph --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-graph .agents/skills/second-brain-graph && 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-graph" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-graph into .agents/skills/second-brain-graph/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-graph", 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-graph -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-graph --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-graph .cursor/skills/second-brain-graph && 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-graph" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-graph into .cursor/skills/second-brain-graph/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-graph", 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-graph--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-graph -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install undefined-ui/second-brain-os second-brain-graph --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-graph .gemini/skills/second-brain-graph && 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-graph" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-graph into .gemini/skills/second-brain-graph/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-graph", 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-graphInstalls 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-graph -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-graph .github/skills/second-brain-graph && 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-graph" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-graph into .github/skills/second-brain-graph/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-graph", 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-graph -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-graph --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-graph .opencode/skills/second-brain-graph && 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-graph" agent skill from https://github.com/undefined-ui/second-brain-os/tree/main/skills/second-brain-graph into .opencode/skills/second-brain-graph/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "second-brain-graph", 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-graph- GitHub stars
- 999
- Token cost
- ~533 tokens
- SKILL.md length
- 180 words
- Files
- 1
- Skills in repo
- 23
- Repo updated
- First seen
- Licence
- MIT
At a glance
Analyse the vault's link graph and report on its shape: orphan rate, average degree, components, hubs, bridges and clusters, with what each number means for retrieval.
- Works in 5 steps: Run the scripts rather than reading… → Compute the four metrics: orphan rate,… → Identify hubs (pages that have swallowed… → …
- The user asks about the health
- 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 Graph is an agent skill from undefined-ui/second-brain-os. Analyse the vault's link graph and report on its shape: orphan rate, average degree, components, hubs, bridges and clusters, with what each number means for retrieval. Use this skill when the user asks about the health or structure of their graph, wants metrics, asks which pages are most connected or most isolated, or asks whether the vault is fragmented. Do NOT use for fixing what it finds, which is second-brain-lint, or for answering a content question.
Its SKILL.md is about 530 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: 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 the health
- Structure of their graph
- Asks which pages are most connected
- Asks whether the vault is fragmented
Example prompts
- “/second-brain-graph”
Workflow steps
5 steps, taken from the first numbered list in SKILL.md.
- Run the scripts rather than reading files: scripts/vault_stats.py for
- Compute the four metrics: orphan rate, average degree, component count,
- Identify hubs (pages that have swallowed the graph) and bridges
- Name the clusters. These are what the vault is actually about, which is
- Say what each number means for answering questions, not just the value.
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 Graph loads about 533 tokens when it runs. Until then it costs about 120 tokens; SKILL.md has 180 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). 180 words, ~533 tokens.
Download SKILL.mdSave it as
.claude/skills/second-brain-graph/SKILL.md (or your agent's skills folder).- name
- second-brain-graph
- description
- Analyse the vault's link graph and report on its shape: orphan rate, average degree, components, hubs, bridges and clusters, with what each number means for retrieval. Use this skill when the user asks about the health or structure of their graph, wants metrics, asks which pages are most connected or most isolated, or asks whether the vault is fragmented. Do NOT use for fixing what it finds, which is second-brain-lint, or for answering a content question.
Analyse the graph
The graph is the search space every answer is drawn from. Its shape decides whether retrieval reaches the relevant material in a few hops or reaches nothing.
Core rule
Report shape and what it means, never fix anything. This skill is read-only.
Workflow
- Run the scripts rather than reading files:
scripts/vault_stats.pyfor counts and degree,scripts/link_check.pyfor orphans and breaks,scripts/graph_export.pywhen deeper analysis is wanted. - Compute the four metrics: orphan rate, average degree, component count, stale-page rate.
- Identify hubs (pages that have swallowed the graph) and bridges (pages connecting otherwise separate clusters).
- Name the clusters. These are what the vault is actually about, which is reliably different from what the user would say it is about.
- Say what each number means for answering questions, not just the value.
Output format
Pages <n> | links <n> | avg degree <n>
Orphan rate <n>% (healthy under 5)
Components <n> (main holds <n>%)
Stale concepts <n>% (untouched 90+ days)
Hubs: <pages with outsized degree, and whether to split them>
Bridges: <pages connecting clusters, and what breaks if they are wrong>
Clusters: <what the vault is actually about>
What this means: <two or three sentences>Calibration
Never report page count or word count as a health signal. Both rise whether the vault is improving or not.
A single reading says little. If the user has recorded previous numbers, compare against them; if not, suggest recording these.
© 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-graph of undefined-ui/second-brain-os.
Open the folder on GitHubat commit d6861cc
Compare with similar skills
Second Brain Graph 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 Graph this skillundefined-ui/second-brain-os | 999 | — | ~533 | 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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nateherkai/AIS-OS
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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…
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NicholasSpisak/second-brain
Set up a new Obsidian knowledge base with the LLM Wiki pattern.
Cascading Goal Tracker
ballred/obsidian-claude-pkm
Tracks three-year, yearly, monthly, and weekly goals in linked Markdown files, calculating completion percentages and flagging stalled goals.
Karpathy Wiki
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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.
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Related
Categories
Questions about Second Brain Graph
What does Second Brain Graph do?
Analyse the vault's link graph and report on its shape: orphan rate, average degree, components, hubs, bridges and clusters, with what each number means for retrieval. Second Brain Graph is an agent skill from undefined-ui/second-brain-os. Analyse the vault's link graph and report on its shape: orphan rate, average degree, components, hubs, bridges and clusters, with what each number means for retrieval.
When should I use Second Brain Graph?
Second Brain Graph fits situations like: the user asks about the health; structure of their graph; asks which pages are most connected; asks whether the vault is fragmented.
How do I install Second Brain Graph in Claude Code?
Run `npx skills add undefined-ui/second-brain-os --skill second-brain-graph -a claude-code`. Or copy the skill folder (skills/second-brain-graph in undefined-ui/second-brain-os) into .claude/skills/second-brain-graph in your project. Claude Code loads it when a task matches its description.
How do I install Second Brain Graph in Codex?
Run `npx skills add undefined-ui/second-brain-os --skill second-brain-graph -a codex`. Or copy the skill folder (skills/second-brain-graph in undefined-ui/second-brain-os) into .agents/skills/second-brain-graph in your project. Codex loads it when a task matches its description.
Can I use Second Brain Graph 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-graph -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-graph, .gemini/skills/second-brain-graph, .github/skills/second-brain-graph and .opencode/skills/second-brain-graph in your project.
What does Second Brain Graph need to run?
SKILL.md names no scripts, command-line tools or credentials: Second Brain Graph is instructions for the agent only.
Does Second Brain Graph 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 Graph 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 Graph use?
Second Brain Graph 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 Graph use?
About 533 tokens (SKILL.md is roughly 2.1k 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 Graph?
Skills that share tags, products or a category with Second Brain Graph: 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 Graph?
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.