openfreebooks-bookgenerator/CONTRIBUTING.md

Contributing to Open Free Books

Thank you for helping grow free, open textbooks.

Readable guide (with examples): openfreebooks.org/contributing — or locally after zola serve → http://127.0.0.1:1111/contributing/

Prerequisites: Zola, Bun. See README.md for dev setup.

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Quick reference

I want to…	Start here
Add a planned chapter (roadmap only)	§ Planned chapter
Publish a live chapter (readable page)	§ Publish a live chapter
Add a branch in the catalog map	§ Chapter graph
Add a new subject	§ New subject
Add a curriculum filter (e.g. GCSE)	§ New curriculum label

Browse the catalog locally: bun run build:js && zola serve → http://127.0.0.1:1111/catalog/

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How the catalog fits together

data/catalog.json              → subjects in the sidebar + filter chips (DSE, IB, …)
data/{subject}-curriculum.json → strands, chapters, curriculum tags, graph.edges
content/{subject}/{slug}/      → actual chapter page (when status is "live")
themes/.../partials/...        → chapter HTML content (today)

• Catalog (/catalog/) — List (numbered cards; live = whole card links) and Map (?view=tree, Mermaid; live = title link only with → and hover underline).
• /math/ redirects to /catalog/?subject=math.
• Curriculum names (DSE, IB, …) appear only in the catalog — not inside chapter text (spec.md).
• Every chapter needs a description in curriculum JSON (map clamps to three lines).

Map graph rules (summary)

Rule	Detail
Edges	Only graph.edges — no automatic chain from strand chapters[] order
Meaning	Each edge is a required prerequisite (from → to)
Scope	Cross-strand edges allowed
Layout	Longest-path levels; siblings at the same level stack vertically in a column
DAG	No cycles — build throws if the graph cycles
tier	Optional foundation (default) or non-foundation (Extension badge)

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Add a planned chapter (roadmap)

Use this when the chapter is not written yet but should appear in the catalog.

1. Open data/{subject}-curriculum.json (e.g. data/math-curriculum.json).
2. Find the right strand (topic group).
3. Add a chapter object:

{
  "slug": "your-chapter-slug",
  "title": "Human-readable title",
  "description": "One or two sentences for the catalog list and map card.",
  "status": "planned",
  "curriculums": ["DSE"],
  "tier": "non-foundation"
}

(tier is optional — omit for foundation topics; non-foundation shows an Extension badge.)

4. Use a kebab-case slug (letters, numbers, hyphens only).
5. Set curriculums to every syllabus tag that applies. Tags must exist in data/catalog.json → curriculums.
6. Run zola build and check /catalog/?subject=math (or your subject).

No content/ files needed for planned chapters.

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Publish a live chapter

A live chapter needs catalog data and a page.

1. Catalog entry

In data/{subject}-curriculum.json, set "status": "live" and include a description (see planned chapter).

2. Zola section

Create content/{subject}/{slug}/_index.md:

+++
title = "Your chapter title"
description = "One sentence for search and previews — no curriculum names here."
template = "math/chapter.html"
weight = 10
[extra]
chapter_id = "your-chapter-slug"
+++

• slug in the path must match slug in the JSON file.
• chapter_id must match the slug (used by the template).
• weight controls order within the section (lower = earlier).

3. Chapter HTML content

Today, chapter bodies live as HTML partials under the theme, not Markdown:

1. Add themes/openfreebooks/templates/partials/math/your-chapter-slug-content.html with the lesson HTML.
2. In themes/openfreebooks/templates/math/chapter.html, include it when chapter_id matches:

{% if section.extra.chapter_id == "your-chapter-slug" %}
{% include "partials/math/your-chapter-slug-content.html" %}
{% endif %}

Use existing classes: book-prose, book-prose__heading, book-callout, etc. Copy from quadratic-equations-content.html.

Do not mention DSE, IB, or other curriculum names in the chapter body.

4. Interactive widgets (optional)

If the chapter needs a Solid widget (like the quadratic explorer):

1. Add a component under frontend/src/components/.
2. Mount it in frontend/src/main.tsx when a mount element exists.
3. Add <div id="your-widget" class="math-widget-mount"></div> in the chapter template branch.

Then run bun run build:js.

5. Check

• /catalog/?subject=math — chapter appears; live chapters link correctly.
• /math/your-chapter-slug/ — page renders; breadcrumb goes to catalog.
• bun run build completes without errors.

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Chapter graph (branches)

The Map tab (?view=tree) shows chapters as a directed graph (strand = column, arrows = prerequisites).

• Prerequisites are only declared in graph.edges (strand list order does not create arrows).
• For branches or merges, add edges:

"graph": {
  "edges": [
    { "from": "quadratic-equations", "to": "sequences-series" },
    { "from": "quadratic-equations", "to": "functions-graphs" },
    { "from": "functions-graphs", "to": "linear-programming" },
    { "from": "sequences-series", "to": "linear-programming" }
  ]
}

Rules:

• from and to are chapter slugs.
• The graph must not contain cycles.
• Edges may cross strands.

Open /catalog/?subject=math&view=tree to verify. Use Ctrl/Cmd + wheel on the map to zoom.

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Add a new subject

Example: adding Science.

1. data/catalog.json — add to subjects:

   { "id": "science", "name": "Science" }
   

2. data/science-curriculum.json — create with title, strands, and chapters (copy structure from math-curriculum.json).

3. themes/openfreebooks/templates/catalog.html — wire the new file into #catalog-data (see math block).

4. content/science/ — add _index.md when you have a section.

5. Homepage — optional card in themes/openfreebooks/templates/index.html.

6. Build and test /catalog/?subject=science.

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Add a curriculum label

Example: adding GCSE.

1. Add "GCSE" to curriculums in data/catalog.json.
2. Tag chapters with "GCSE" in their curriculums arrays.
3. Add a badge style in themes/openfreebooks/sass/_catalog.scss (copy .catalog-badge--igcse pattern).
4. Add a mapping in frontend/src/lib/catalog-badge.ts → curriculumBadgeClass() (or rely on the default style).

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Development & tests

bun install
bun run build:js    # after frontend/ changes
zola serve
bun test            # catalog map generation (catalog-to-mermaid)
bun run build

• Commit themes/openfreebooks/static/js/ after build:js.
• Do not commit public/.

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Pull requests

• Keep changes focused (one subject or a few chapters per PR is fine).
• Run bun run build before opening the PR.
• Describe what you added: subject, chapters, live vs planned, and which curricula apply.

Questions? Open a GitHub discussion or issue.

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For maintainers & agents

Machine-oriented detail: .agents/skills/ofb/SKILL.md and .agents/skills/ofb/curriculum-data.md.