Stage.js

HTML presentations that people and coding agents can work on together. No build step, runtime dependencies, or external services required.

Why HTML?

A presentation can be source code. A coding agent can read a deck's HTML, edit its content and CSS, preview it in a browser, and check the result using the same tools it uses to build software. Changes are plain-text Git diffs that you can review, version, and collaborate on.

PowerPoint is proprietary software, with an authoring workflow centered on its editor. Stage.js uses HTML, CSS, and JavaScript directly: content, design, and behavior are inspectable and editable without a specialized presentation editor. This makes the deck a natural part of an agent-assisted coding workflow.

Explore the live samples.

Get started

Open the basic sample in a browser, or serve the repository locally:

python3 -m http.server 8000

Visit the basic deck or the advanced deck. Copy a sample folder inside sample_projects/ and edit its index.html to start your own deck. Ask your coding agent to update the slide content and theme, then review the result in the browser.

Use the arrow keys to navigate and F for fullscreen. Before a talk, press P to open the separate presenter window; share only the audience window.

What is included

• A shared runtime with slide navigation, overview, appendices, and reading mode.
• A separate presenter window with notes, current/next previews, and a timer.
• Shareable CSS themes, including light and dark slide layouts.
• Local images and videos, optional enlargement, and playback coordination.
• Browser printing and a PDF export helper.

The basic sample is a four-slide starter. The advanced sample adds light/dark layouts and appendices. Both use the same runtime and matching local media.

Documentation

• Authoring: slide markup, media, validation, PDF export, and sharing.
• Presenting: controls, shortcuts, notes, and presenter setup.
• Themes: styling responsibilities, theme tokens, and responsive layouts.
• Runtime: project structure, component APIs, and playback policy.

License and credits

Released under the MIT License.

Co-authored with OpenAI Codex, with design guidance from Anthropic's Frontend Design Skill for Claude.