Open Free Books

Free, open-source textbooks for every learner — from elementary school through university. The site is fully static, open on GitHub, and deployed to Cloudflare.

Live site: openfreebooks.org

Stack

Layer	Tool
Site generator	Zola
Theme	Custom theme in themes/openfreebooks/
Interactivity	Solid.js (header, marquee, scroll reveal, theme toggle)
JS build	Bun + Vite
Hosting	Cloudflare Workers (static assets via Wrangler)

Chapter content is HTML partials in the theme today (not Markdown). Canvas maps use the JSON Canvas standard (Obsidian-compatible) via json-canvas-viewer.

Contributing curriculum, subjects, or chapters? See CONTRIBUTING.md.

Prerequisites

• Zola 0.19+
• Bun (for frontend build)
• Wrangler 4.x (for deploy)

Project layout

content/                 # Pages and sections (Markdown front matter)
data/                    # Catalog + per-subject curriculum JSON
static/                  # Site assets copied to public/ (favicons, _redirects)
themes/openfreebooks/    # Zola theme
  templates/             # HTML (Tera)
  sass/                  # Stylesheets (compiled to main.css)
  static/js/bundle.js    # Built Solid bundle (committed for simple deploys)
frontend/src/            # Solid.js source
public/                  # Zola build output (gitignored) — Wrangler deploy target
wrangler.jsonc           # Cloudflare Workers static assets config

Development

Install JS dependencies:

bun install

Build the Solid bundle and start Zola’s dev server:

bun run build:js
zola serve

Open http://127.0.0.1:1111. Re-run bun run build:js (or bun run dev:js in another terminal) when you change frontend/.

Production build

bun run build

This runs vite build (outputs to themes/openfreebooks/static/js/bundle.js) and then zola build (outputs to public/).

Deploy to Cloudflare

bun run build
wrangler deploy

The Worker name is openfreebooks (see wrangler.jsonc). Assets are served from public/ with no server-side logic.

Configuration

Site-wide settings live in zola.toml:

• base_url — canonical URL for feeds and absolute links
• [extra] — site_title, github_url, browse_url, about_url (used in templates and the Solid config block)

Theme notes

The visual design is inspired by manlung.work: paper background with grain, Instrument Serif headings, warm ochre accent (#9a6b2e), and light/dark mode (system preference plus a toggle).

Keep themes/openfreebooks/static/ clean. Only committed built assets belong there (currently js/bundle.js). Do not copy Zola’s public/ output into the theme static/ folder — that pollutes public/js/ on the next build.

Contributor experience — known friction (task list)

These issues make contributions harder than they should be. PRs that fix any item are welcome.

Catalog & data

• Auto-wire subjects in catalog.html — stop hardcoding if subject.id == "math"; load data/{id}-curriculum.json by subject id convention.
• Single source for subjects — merge catalog.json subject stubs and {subject}-curriculum.json or generate one from the other at build time.
• scripts/validate-curriculum.ts — JSON schema check: slugs, curriculums ⊆ global list, live chapters have content/, graph.edges acyclic.
• Document or script new curriculum labels — today requires catalog.json, Sass badge, and TS curriculumBadgeClass() mapping.

Chapters & content

• Generic chapter template — drop per-chapter {% if chapter_id %} branches; load partials/{subject}/{slug}-content.html by convention.
• Strand kicker from data — chapter header still hardcodes “Number & Algebra”; should come from strand in curriculum JSON.
• Subject-agnostic chapter template — breadcrumb/catalog URL and load_data path should use section path, not math only.
• Markdown chapters (optional) — README/spec disagree on format; if staying HTML, document clearly everywhere.
• Defuddle “copy as Markdown” — spec calls for it on every page; not implemented.

Site & discoverability

• Data-driven homepage cards — “Browse by subject” / featured blocks duplicate manual edits in index.html.
• Pagefind search — spec mentions search; build_search_index = false and no index step in build.
• CONTRIBUTING wizard or checklist in CI — fail PR if live chapter missing partial or catalog entry.

Build & repo hygiene

• Prevent stale theme static/**/*.html — committed copies under themes/openfreebooks/static/ override Zola output (index, catalog, math); add CI check or pre-commit.
• Clarify package manager — project uses Bun (bun run build); align docs/tooling if pnpm is preferred elsewhere.
• dev one-liner — e.g. bun run dev running vite build --watch + zola serve together.

New subject onboarding

• Subject scaffold command — e.g. bun run scaffold:subject science creating data/science-curriculum.json, content/science/_index.md, and catalog entry.
• Redirect template generic — math-redirect.html → subject-redirect.html using ?subject= from section path.

Agent skills

Skill	Path	Use
OFB (this project)	.agents/skills/ofb/SKILL.md	Catalog, curriculum JSON, chapters, product rules
Zola + Solid	.agents/skills/zola/SKILL.md	Templates, Sass, bundle, zola serve

License

Open source — see the repository license file when added.