Fabula, a storyboard for your docs' navigation: see it whole, retell it, re-imagine it.
See your documentation's table of contents the way readers never can — as a whole — and reshape it by dragging, with a lossless round-trip back to the file your doc system actually reads.
Documentation information architecture lives in TOC files (toc.yml,
mkdocs.yml and kin) that are edited as text: deeply nested YAML where
"move this subtree under that section" means error-prone cut-and-paste,
and where nobody can see the shape of the whole navigation at once.
Fabula turns that file into cards on an infinite canvas.
- Comprehend — load a TOC and immediately grasp its structure: section sizes, depth, distribution, outliers. Pan, zoom, minimap, per-card and global depth controls, per-card YAML view.
- Restructure — drag topics (or whole subtrees) within and between sections, drag a parent onto the canvas to split it into its own section, multi-select and move groups, rename inline, reorder cards. Every operation is undoable, and undo is animated so you can see exactly what changed back.
- Compare — sketch alternative structures in separate tabs (duplicate a tab, rearrange, compare) before committing to one.
- Export — write the result back to the exact same format, losslessly: an unchanged document exports byte-stable, and an edit changes only what you touched. Properties the app doesn't understand are preserved verbatim.
- Reorganize with AI (optional) — bring your own API key (Gemini free tier, Claude, or any OpenAI-compatible endpoint). Only topic titles are sent — never paths, file names, or file contents — and results open as a new tab; the original is never touched.
- Private by design — a pure client-side app. No accounts, no server, no analytics; your TOC never leaves the browser (the optional AI step above — titles only, on your own key — is the single exception). Sessions persist locally.
| Format | Source | Status |
|---|---|---|
| DocFX | toc.yml |
✅ |
| MkDocs | nav: in mkdocs.yml (surrounding config preserved) |
✅ |
| Mintlify | docs.json (byte-identical round trip) |
✅ |
| Just the Docs | per-page frontmatter across a docs folder | ✅ |
| Docusaurus (autogenerated sidebar) | directory tree + _category_.json |
✅ |
| Hugo | content/ tree + page front matter, incl. moving pages between sections |
✅ |
| Sphinx | toctree directives across files — write-back is moves-only |
✅ |
| GitBook, VitePress, mdBook… | contributions welcome |
Single-file formats round-trip through Export. Folder-based
systems (Just the Docs, Docusaurus, Hugo, Sphinx) import from a local
folder or a GitHub /tree/ URL and write back as reviewed, minimal
per-file edits — saved straight into the folder (Chromium) or
downloaded as a git-applyable .patch. Every plan is verified by
simulation before it can be saved, and files are never deleted.
Saving straight into a folder uses the File System Access API, which
is Chromium-only. In Safari and Firefox, folder import works through
the standard directory picker, and write-back is the downloadable
.patch — which works everywhere.
Support for a new system is deliberately a small contribution: one adapter file, one fixture, one registry line, validated by a shared conformance suite. See CONTRIBUTING.md.
pnpm install
pnpm dev # http://localhost:5173Node ≥ 22, pnpm ≥ 10. pnpm test runs the unit/property/conformance
suites; pnpm e2e runs the Playwright flows.
TypeScript + React + Zustand. Every mutation is a command executed
through Immer's produceWithPatches, so undo/redo are derived inverse
patches — never hand-written. Format knowledge lives entirely in
adapters behind a small interface; the core never sees a YAML dialect.
Property-based tests (fast-check) hold the load-bearing invariant: any
command sequence, undone completely, restores the document byte-for-byte
on export.
The design docs in docs/ cover the full story — vision,
requirements, architecture, the adapter contract, interaction and
animation rules, testing strategy, and the lessons the design
refuses to relearn.
AGPL-3.0. If you host a modified Fabula, you must offer its source to your users.