What is book_chapter.fix_headings?

A heading-correction tool for lecture sources and generated Typst book chapters. Typst is a markup language used to generate formatted documents, and the tool aligns chapter headings and slide titles with the source structure.

Use it to fix heading levels and convert slide titles that should act as transitions in a generated book chapter.

It removes mismatches introduced by older generation rules or manual edits without rewriting the chapter's prose. If the files already follow the rule, it makes no changes.

book_chapter.fix_headings — Skill for Claude Code by gpsaggese/helpers

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 gpsaggese/helpers --skill book_chapter.fix_headings

Clone the repo

git clone --depth 1 https://github.com/gpsaggese/helpers

Made for: Claude Code.

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.

README.md

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Your own site

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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.

Your own site · 80×15

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Per session 16 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,544 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.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00016	$0.01544
Opus 5.5	$0.00006	$0.00618
Sonnet 5.5	$0.00003	$0.00309
Haiku 4.5	$0.00002	$0.00154

Measured yesterday against content hash d32e15ff12cc, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

book_chapter.fix_headings 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 yesterday.

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.

.claude/skills/book_chapter.fix_headings/SKILL.md · 108 lines

How it starts

The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Goal

Given a lecture's .smd source and its generated .typ book chapter (from gen_book_chapter.py --mode typst_aima), fix the heading levels and slide-title handling to follow the "Structural Hierarchy" rule in .claude/skills/typst.rules.md
Mostly mechanical (moving =/==/=== markers). A slide title that must become a transition (see Step 3) needs one reworded sentence. That is the only text this skill may change. The rest of the prose stays untouched
A fix-up for chapters generated before that rule existed, or hand-edited inconsistently. On a chapter that already follows the rule, it is a no-op

Inputs

<SMD_FILE>: the lecture source
- E.g., msml610/lectures_source/Lesson02.1-A_Map_of_Machine_Learning.smd
<TYP_FILE>: the generated book chapter for <SMD_FILE>
- E.g., msml610/book/Lesson02.1-A_Map_of_Machine_Learning.typ

Workflow

Classify Every Heading/slide in `<SMD_FILE>`

Walk <SMD_FILE> top to bottom, collecting every #/##/###(+) heading line and every * Slide Title line, in source order, with its line number
Track one running flag, seen_subheading, starting False: flip it to True the first time a ## or deeper heading is seen. Its value when each * Slide Title line is reached (before any ## on the same line updates it) is what Step 3 needs for that slide

Locate the Matching Line in `<TYP_FILE>`

<TYP_FILE> carries a
```
// From: <SMD_FILE>:<LINE_NUMBER> '<MARKER> <TITLE>'
// Slide: <TITLE>
```
comment immediately above every heading/slide it was generated from. Match each Step 1 entry by line number + marker, not by title alone, since titles can repeat (e.g., a lesson and its own first slide sharing a name)
The heading/title line itself is the next non-comment line after // Slide: <TITLE>: it may currently be #strong[Title], = Title / == Title / === Title, or missing entirely (the block's paragraph starts right after the comment, no title line at all)

Read the full file on GitHub · 108 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.

yesterday First seen · 108 lines · 16 tokens per session scan A d32e15ff12cc

Subscribe to this mod's changes

book_chapter.fix_headings is a skill published in the GitHub repository gpsaggese/helpers (158 stars, last pushed today), licensed Apache-2.0. It adds 16 tokens to every session and 1,544 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-11-06.

Writing and docs

book_chapter.fix_headings next to 6 skills from other repositories
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book_chapter.fix_headingsgpsaggese/helpers	Skill	158	today	Apache-2.0	A	16	Claude Code
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