markdown-toc

markdown-toc is a skill for Claude Code, Codex from ByJH/airlock. It costs 16 tokens per session (82 once invoked), scanned A, original, MIT.

A utility that builds a nested table of contents from the headings in a Markdown file. Markdown is a plain-text format that uses markers such as # for headings.

In plain words
What is it for?
Use it to generate a table of contents for a README or another Markdown document.
Why use it?
It saves you from manually listing and nesting headings, while ignoring heading-like text inside fenced code blocks.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/byjh/airlock/markdown-toc
Any agent
npx skills add ByJH/airlock --skill markdown-toc
Clone the repo
git clone --depth 1 https://github.com/ByJH/airlock

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 markdown-toc

README.md
[![agentmods](https://agentmods.dev/badge/skills/byjh/airlock/markdown-toc.svg)](https://agentmods.dev/skills/byjh/airlock/markdown-toc)
Your own site
<a href="https://agentmods.dev/skills/byjh/airlock/markdown-toc"><img src="https://agentmods.dev/badge/skills/byjh/airlock/markdown-toc.svg" alt="Measured on agentmods" height="20"></a>
Per session 16 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 82 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00016 $0.00082
Opus 5 $0.00008 $0.00041
Sonnet 5 $0.00003 $0.00016
Haiku 4.5 $0.00002 $0.00008

Measured 2d ago against content hash 6f5a2d350002, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

markdown-toc 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 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (toc.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

eval/fixtures/benign/markdown-toc/SKILL.md · 16 lines

What it actually says

Markdown TOC

Reads the Markdown file you name and prints a nested list of its headings. It ignores fenced code blocks so a # inside code is not mistaken for a heading.

Usage

toc.py README.md

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 16 lines · 16 tokens per session scan A 6f5a2d350002

Subscribe to this mod's changes

markdown-toc is a skill published in the GitHub repository ByJH/airlock (0 stars, last pushed 1mo ago), licensed MIT. It adds 16 tokens to every session and 82 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 2026-08-31.

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