Zero-Config In-Browser CMS

Warning

Work in Progress (Alpha): ZeroCMS is an experimental project. Many features are partially implemented, and you may encounter bugs. We are currently building the core engine—expect breaking changes.

A production-ready, zero-config CMS that runs a development environment (Astro, Vite, etc.) entirely in your browser using WebContainers and isomorphic-git.

📖 Documentation

None. It's Zero-Config.

Getting Started

ZeroCMS is designed to be completely zero-setup. You don't need to configure .env files, databases, or local development environments.

1. Install the GitHub App: Install 0CMS on your repositories.
2. Authorize: Approve the App to grant access to the projects you want to manage.
3. Edit: Select a repository. Our engine boots your site directly in the browser—start visually editing instantly!

How it works

🛠 Features

• In-Browser Dev Server: Runs Node.js directly in the browser via WebContainers.
• Zero-Config: No backend required; uses isomorphic-git for Git operations.
• Visual Editing: Directly modify your site's content in an iframe.
• Persistent Storage: Uses lightning-fs to keep your repository in IndexedDB.
• Seamless Publishing: Commits and pushes changes directly to GitHub.

🚧 Work in Progress / Next Steps

1. Responsive Preview: Test website across Mobile, Tablet, and Desktop directly in the dashboard. (Current Focus)
2. Content Creation: Generate new pages or list items (e.g., from Markdown templates).
3. SEO & Assets: Meta-editor for OpenGraph tags and a central Media Library.
4. One-Click Deploy: Automated deployments via Vercel/Cloudflare integration.

• index.html: The modern dashboard for managing your repositories.
• WebContainerGitService.js: The core logic for Git and WebContainer orchestration.
• cms.js: The visual editor bridge that runs inside the preview iframe.
• serve.js: A simple Node.js server providing COOP/COEP headers.
• .env: (Ignored) Contains your GitHub credentials.

🏗 Architecture

ZeroCMS uses a unique high-performance architecture:

• Quantum Boot: Background pre-warming of WebContainers before the user even opens the dashboard.
• Visual Bridge: A zero-config postMessage bridge that allows the host to edit the iframe content in-place.
• Binary Snapshots: Uses tar blobs in IndexedDB to skip npm install for previously loaded repositories.

🛡️ Security & Sandboxing

ZeroCMS is designed with a Zero-Trust security model. Running untrusted code (like npm run dev) from a third-party repository is safer here than on your local machine:

1. Browser Sandbox: The entire Node.js runtime (WebContainer) executes inside the browser's security sandbox.
2. Total Isolation: Malicious scripts cannot "break out" of the browser tab. They have no access to your local files, system registry, passwords, or local network.
3. Disposable Environments: Every session is isolated. If a repository contains harmful code, it only affects its own virtual filesystem within that specific tab. Closing the tab wipes the environment completely.

🚀 Framework Support

ZeroCMS uses a Declarative Driver system. While the engine is designed to be universal, specific support is being built out one-by-one.

• Stable: Astro, Hexo, Generic Vite (Static).
• Experimental: Next.js (Static Export), Eleventy.
• Planned / Stubs: Nuxt, SvelteKit, Remix, Hugo (Go-WASM required).

🏗 Modular Architecture ("Architectural Gold")

We strive for what we call "Architectural Gold"—patterns that are clean, modular, and highly performant. However, we are still refining these implementations:

1. Deterministic Traceability: Using invisible Unicode breadcrumbs to map rendered DOM elements back to their exact source file and line number with 100% accuracy.
2. Hybrid WASM Core: A pluggable engine that uses JavaScript for instant starts on small projects and switches to Rust (WASM) for massive monorepos. (Note: Rust binary is currently in development).
3. Quantum Pre-warming: The WebContainer engine starts booting the second you hit the landing page, ensuring the dashboard is ready before you even finish logging in.
4. Zero-Copy Memory: Using SharedArrayBuffer and TypedArrays to share project data between the UI and the WASM engine without slow serialization.

⚠️ Current Limitations (Be Aware)

• Mocked WASM: The high-performance Rust tagger is currently mocked via a JavaScript fallback.
• Parsing Fidelity: Complex template logic (nested Nunjucks/Liquid) may still struggle with edge cases during tagging.
• Static Only: We currently focus on SSG (Static Site Generation). SSR (Server Side Rendering) support within the preview is limited.
• Git Conflicts: Automated conflict resolution during "Publish" is still manual.

🤝 Contributing & Self-Hosting

ZeroCMS is an open-source project. If you wish to self-host or contribute to the core:

1. Install Bun: Bun.sh is required for development and building.
2. Fork & Clone the repository.
3. Setup a .env file with your own GITHUB_CLIENT_ID and GITHUB_CLIENT_SECRET from a custom GitHub OAuth App.
4. Run bun install && bun start. The dev environment runs on localhost:3000.
5. Build for production via bun run build. The output will be in the /dist directory.
6. Develop your feature or fix and submit a PR!

Please ensure your code follows the existing minimalist aesthetic and uses vanilla JS/CSS where possible.

❤️ Sponsors

ZeroCMS is an open-source project. If you find it useful, please consider supporting its development:

• GitHub Sponsors: Support our work
• Open Collective: Join our community

⚠️ Important Note on WebContainers

WebContainers require specific HTTP headers to function correctly:

• Cross-Origin-Embedder-Policy: require-corp
• Cross-Origin-Opener-Policy: same-origin

The included serve.js automatically provides these headers. If you deploy this to a production environment (e.g., Vercel, Netlify), you must configure these headers in your platform's settings.

📄 License

MIT