obsidian

obsidian is a skill for Claude Code, Codex from laude-institute/headlong. It costs 18 tokens per session (1,031 once invoked), scanned A, original, Apache-2.0.

A file-based connection for reading, creating, editing, searching, and managing notes in an Obsidian vault. Obsidian is a note-taking app that stores notes as Markdown files in a folder.

In plain words
What is it for?
It helps find notes, read their contents, create new Markdown notes, append or replace text, and search across the vault.
Why use it?
It lets file changes appear automatically in Obsidian without editing the app’s internal settings folder.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps find notes, read their contents, create new Markdown notes, append or replace text, and search across the vault.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/laude-institute/headlong/obsidian
About the project

Headlong is a Bash-based agent microharness for running language-model agents in persistent, self-directed loops. People use it to create agents that maintain ongoing interests and projects, interact through shell commands, and share one stream of conversations across a team and chat services.

laude-institute/headlong · 1,135 stars · on GitHub · headlong.ai

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add laude-institute/headlong --skill obsidian
Clone the repo
git clone --depth 1 https://github.com/laude-institute/headlong

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for obsidian

README.md
[![agentmods](https://agentmods.dev/badge/skills/laude-institute/headlong/obsidian/github.svg)](https://agentmods.dev/skills/laude-institute/headlong/obsidian)
Your own site
<a href="https://agentmods.dev/skills/laude-institute/headlong/obsidian"><img src="https://agentmods.dev/badge/skills/laude-institute/headlong/obsidian/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for obsidian

Your own site · 80×15
<a href="https://agentmods.dev/skills/laude-institute/headlong/obsidian"><img src="https://agentmods.dev/badge/skills/laude-institute/headlong/obsidian.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,031 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Tool Misuse · line 77
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00018 $0.01031
Opus 5 $0.00009 $0.00515
Sonnet 5 $0.00004 $0.00206
Haiku 4.5 $0.00002 $0.00103

Measured 9d ago against content hash 466c250a5dd7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

obsidian scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/obsidian/SKILL.md · 127 lines

How it starts

The opening of the file, as written. The whole thing — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.

obsidian — Obsidian vault management

Overview

An Obsidian vault is a folder of markdown files with a .obsidian/ config directory. The OBSIDIAN_VAULT environment variable must point to the vault root. All operations are filesystem-based — Obsidian detects changes automatically when running.

Obsidian Sync

Obsidian watches the vault directory for filesystem changes. When Obsidian is running, any file you create, edit, or delete is picked up and synced automatically (if Obsidian Sync or a sync plugin is configured). Never modify anything inside .obsidian/ directly.

Filesystem operations

Read a note

cat "$OBSIDIAN_VAULT/path/to/note.md"

List notes

# All notes
find "$OBSIDIAN_VAULT" -name '*.md' -not -path '*/.obsidian/*'

# Notes in a specific folder
ls "$OBSIDIAN_VAULT/folder/"*.md

Create a note

cat > "$OBSIDIAN_VAULT/path/to/note.md" << 'EOF'
---
tags: [topic]
---

Note content here.
EOF

Edit a note (append)

echo "New content" >> "$OBSIDIAN_VAULT/path/to/note.md"

Edit a note (overwrite)

cat > "$OBSIDIAN_VAULT/path/to/note.md" << 'EOF'
Replacement content.
EOF

Search by content

grep -rl "search term" "$OBSIDIAN_VAULT" --include='*.md' | grep -v '.obsidian/'

Search by filename

find "$OBSIDIAN_VAULT" -name '*keyword*' -name '*.md' -not -path '*/.obsidian/*'

Move / rename

mv "$OBSIDIAN_VAULT/old/path.md" "$OBSIDIAN_VAULT/new/path.md"

Note: Moving or renaming files does not automatically update [[wikilinks]] pointing to that note. If the note is linked from others, update those references manually or rely on Obsidian's built-in rename refactoring (which only works when Obsidian performs the rename via its UI).

Delete a note

rm "$OBSIDIAN_VAULT/path/to/note.md"

Manage folders

mkdir -p "$OBSIDIAN_VAULT/new/folder"
rmdir "$OBSIDIAN_VAULT/empty/folder"

Find notes with a tag

grep -rl '#tagname' "$OBSIDIAN_VAULT" --include='*.md' | grep -v '.obsidian/'

Read the full file on GitHub · 127 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 127 lines · 18 tokens per session scan A 466c250a5dd7

Subscribe to this mod's changes

obsidian is a skill published in the GitHub repository laude-institute/headlong (1,135 stars, last pushed 4d ago), licensed Apache-2.0. It adds 18 tokens to every session and 1,031 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.