Updato

Push updates from GitHub, applied live in the browser with no server.

Live Demo | Documentation | npm

Updato is a decentralized update system for web apps. A GitHub Action publishes build artifacts to a CDN branch. A Cloudflare Worker tells clients when a new version exists. The client downloads and hot-swaps files without a page reload.

How it works

Git Push  →  GitHub Action  →  CDN branch (manifest.json + assets)
                                         ↓
                              Cloudflare Worker (version checks)
                                         ↓
                              Client downloads and hot-swaps

Features

• No backend server - Updates come from GitHub's raw content CDN. The Worker only answers version checks.
• Live hot-swap - Scripts, stylesheets, and images swap in place. No flash, no reload. CSS uses CSSStyleSheet.replaceSync for CSP-safe replacement.
• Two modes - Version mode uses semver comparison. Commit mode uses SHA hashes for canary rollouts.
• Optional metrics - localStorage-backed download telemetry. Opt-in, never sent anywhere.

Quick start

1. Add the GitHub Action

- uses: NellowTCS/[email protected]
  with:
    mode: version
    dist_dir: dist
    build_script: npm run build
    github_token: ${{ secrets.GITHUB_TOKEN }}

Requires permissions: contents: write. Pushes build output to a cdn branch with a manifest.

2. Deploy the Worker

cd Worker
npm install
npx wrangler deploy

The Worker needs a KV namespace bound as UPDATO_KV. See the docs for wrangler config.

3. Wire the client

import { Updato } from "@nellowtcs/updato";

const updater = Updato.init(
  {
    repo: "my-org/my-app",
    mode: "version",
    current: "1.0.0",
  },
  {
    onUpdate: (info) => {
      console.log(`Version ${info.latest} available`);
    },
  },
);

For the full flow (check, download, apply) see the quick start guide.

Project structure

Action/      -- GitHub Action (publishes builds to CDN branch)
Worker/      -- Cloudflare Worker (version check API)
Build/       -- Client library (npm package)
Demo/        -- Live demo app
Docs/        -- Documentation site (docmd)

Publishing modes

• version - Version from package.json or explicit input. Uses semver comparison. Good for tagged releases.
• commit - Uses the Git commit SHA. Any push triggers an update. Good for canary builds.

License

MIT