# [Bento — the office suite that fits in a file](https://bento.page/) **This PowerPoint alternative is a single HTML file.** A Bento deck carries its own viewer, presenter, and editor inside the document — open it in any browser, edit it, present it, send it. The person you send it to needs nothing: the file *is* the software. **Try it in 10 seconds:** open [bento.page/slides](https://bento.page/slides) — that's the entire app, running on a starter deck that doubles as the feature tour. Or grab a designed template from the [gallery](https://bento.page/) and make it yours. **Download the app:** grab the single `Bento_Slides.bento.html` from the [GitHub Releases](https://github.com/nyblnet/bento/releases) page or straight from [bento.page](https://bento.page/releases/slides/Bento_Slides.bento.html) (~560 KB, no account, no installer). Open it in any modern browser and it *is* the editor. Save, and it rewrites itself with your deck inside. ## Why this exists Office documents used to be things you *had*. Now they're things you rent — locked in someone's cloud, behind someone's login, readable only while a company keeps its servers on. Bento takes the other path: - **One file, forever.** Deck, fonts, images, charts, animations, and the full editor travel together. A copy from 2026 will open in 2036. - **View-source honest.** Your data sits in a plain, readable JSON block at the top of the file. No binary formats, no lock-in, no archaeology. - **It saves itself.** The file rewrites its own data block on save (File System Access API, with a download fallback). No app to install, ever. - **Local-first, provably.** Flip on Offline mode and nothing leaves your machine — updates and collaboration are hard-blocked, and the app says so. ## What's inside | Feature | Description | |---|---| | **Morph presenting** | Elements that share an id animate between slides — position, size, color, even gradients. Duplicate a slide, rearrange, and the motion designs itself. | | **Live collaboration** | E2EE (AES-GCM) with keys that live in your file, never on a server. The file itself is the invitation: anyone who opens a copy joins. Offline edits merge back precisely — our own CRDT, character-level text merging included. | | **A blind relay** | The optional sync relay ([`server/sync-worker/`](server/sync-worker/)) stores ciphertext and learns nothing. Read the source; it's about one file. | | **Charts, built in** | Bar / line / pie / scatter drawn by our own dependency-free engine, live during presentations: tooltips, zoom, and data that morphs when a bar chart becomes a pie. | | **Designed for AI** | The document is plain JSON in the file, so agents edit `.bento.html` files in place and chatbots round-trip the JSON (`window.bento.loadDoc`). See [docs/agents.md](docs/agents.md). | | **Signed self-updates** | Releases are ECDSA-signed and offered in-app. Updating writes a *new* file — the old one stays as your rollback. No server ever touches your documents. | | **Everything else** | Speaker view, comments, layouts, hidden interactive states, hover reveals, motion paths, PDF export, page sizes, 8 UI languages — in a ~560 KB shell. | ## Use it with AI Because the document is plain JSON living in one plaintext block near the top of the file, any assistant that can read and write a file can edit your deck — no plugin, no API. Two ways in: - **File harnesses** edit the `#bento-doc` JSON in place: [Claude Code](https://claude.com/claude-code), Cursor, Aider, or any agent with filesystem access. Claude Code users get a packaged `bento-slides` skill (installable from this repo's plugin marketplace: `/plugin marketplace add nyblnet/bento`) that even downloads the latest Bento app by itself. - **Chat round-trip** for any chatbot: copy the document JSON out (*About → Copy document JSON*), let the assistant rewrite it, paste it back. **It works fully offline with local open-weight models** — point [Ollama](https://ollama.com), llama.cpp, or LM Studio at the deck and nothing leaves your machine. The agent guide is a single page you can drop into any model's context: [bento.page/agents.md](https://bento.page/agents.md) (also in this repo at [docs/agents.md](docs/agents.md)). ## Architecture in one paragraph `slides/src/model.ts` defines the JSON document model; one renderer (`render.ts`) draws it for the editor canvas, thumbnails, and present mode (Reveal.js drives navigation; morphs are computed from the model, not the DOM). Animation is an in-house engine (`anim.ts`), charts are in-house (`charts.ts`), collaboration is an in-house CRDT (`sync/crdt.ts` — pure data, fuzz-tested by `scripts/test-sync.ts` across hundreds of thousands of convergence checks). The shell compresses to ~560 KB with the document block left as plaintext so old files and outside tools can always splice it. The deep dive: [docs/architecture.md](docs/architecture.md). ## Security model, honestly - Collab keys are minted client-side at document creation and live only in the file. Possession of the file = membership; "Rotate keys" = revocation. - The relay sees: ciphertext, connection timing, and a hash of the room key. It cannot read content, names, or structure. - Presence names are claims, not proofs — fine within a shared-key room; enterprise identity would need signed frames (designed, not built). - Update checks fetch a static manifest and send nothing about you or your document. Signature + hash + version monotonicity are verified in-app. - Known trade-offs: undo during live collab is snapshot-based and can revert a collaborator's concurrent edit to the same property; editing is desktop-first (phones view and present well). ## Build from source Node 20+ and npm are all you need — the app is a single-page build with no backend to stand up. ```bash cd slides npm install npm run dev # dev server (http://localhost:5173) npm run build:single # → dist-single/Bento_Slides.bento.html (the product) ``` `node scripts/test-sync.ts` runs the CRDT convergence rig. Releases are cut locally so the signing key never leaves the maintainer's machine — see [docs/RELEASING.md](docs/RELEASING.md). ## Where to read more - [CLAUDE.md](CLAUDE.md) — the deep architecture + development guide (also what AI agents read to work in this repo). - [docs/architecture.md](docs/architecture.md) — how a `.bento.html` file is built, the on-disk format, and the runtime layout. - [docs/format.md](docs/format.md) — the normative `bento/slides` document-model spec (every element type, slide/state/layout shape, and collab fields). - [docs/collab-design.md](docs/collab-design.md) — the CRDT, E2EE relay, and signed-write RBAC design + threat model. - [docs/agents.md](docs/agents.md) — the document format, for AI agents. - [CHANGELOG.md](CHANGELOG.md) — the version history. - **Layout:** `slides/` is the app (source in `slides/src/`); `server/sync-worker/` is the blind relay; `docs/` and `scripts/` are the guides and build tooling. Contributions welcome — start with [CONTRIBUTING.md](CONTRIBUTING.md). Found a security issue? See [SECURITY.md](SECURITY.md). ## Roadmap **Bento/Slides** is the first app of Bento/Suite — a PowerPoint alternative, shipping now. **Docs** (`bento/docs`) and **Sheets** (`bento/sheets`) follow, each as its own self-contained `.bento.html` distributable. The current release lives on [bento.page](https://bento.page) and reaches every existing file through the signed update channel. ## License Bento is open source under the [MIT License](LICENSE) — all software here is MIT, © 2026 The Bento/Suite authors. Bundled runtime components (reveal.js, Moveable, Selecto) are MIT; the embedded typefaces (Fraunces, Instrument Sans) are OFL; gallery imagery is public-domain (see `scripts/gallery-photos/SOURCES.md`). Each component keeps its own license.