Updato

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

The whole pipeline has three pieces: a GitHub Action that deploys builds, a Worker that checks versions, and a client library that applies updates live.

What it solves

You ship a static web app and need to update it without asking users to refresh. Normally that means a WebSocket server, a bunch of state management, and a deployment pipeline that knows about both.

Updato replaces that with a GitHub repo, a config file, and four lines of client code. The CDN branch is your deployment target. The Worker is the version authority. The client handles the rest.

Features

Decentralized

No backend server. Updates come from your GitHub repo’s raw content CDN. The Worker only answers version checks.

Live

Scripts, stylesheets, and images swap in place using CSSStyleSheet.replaceSync and DOM replacement. No flash, no reload.

Two

Version mode uses semantic version comparison (1.2.0 > 1.1.0). Commit mode compares SHA hashes for canary-style rollouts.

Optional

Built-in localStorage-backed download telemetry. File size, duration, and URL for each downloaded asset. Opt-in, never sent anywhere.

CSP-Safe

CSS hot-swap uses CSSStyleSheet.replaceSync and adoptedStyleSheets . No inline <style> tags, no data: URIs. Works with strict Content Security Policy.

Quick Example

Client-side:

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`);
    },
  },
);

Deploy a new version (GitHub Action):

- uses: NellowTCS/updato@1.0.3
  with:
    mode: version
    dist_dir: dist
    build_script: npm run build

Push or merge to your default branch. The Action builds, copies to a cdn branch, writes a manifest, and the Worker routes clients to the new assets.

Next Steps

Next Quick Start