koruDocumentation
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Your web app, on Android.

Create, preview and ship Android apps with HTML, CSS and JavaScript. koru is a single Go binary: it builds signed APKs without Java, Gradle or the Android SDK.

Create your first app I have a web project

With koru installed, these four commands take you from nothing to an app on your phone:

koru create my-app   # pick a name and a template
cd my-app
koru dev             # preview in the browser with live reload
koru run             # install and open on a device or emulator

New to koru? Install it in one step.

What would you like to do?

Create an appInstall koru, start from a template and open it on Android. Use your frameworkPackage Vite, React, Vue, Svelte, Astro or any static output. Develop fasterLive reload in the browser with the same JavaScript API. Add Android featuresStore data, share text, vibrate and show notifications. Share your appBuild a release APK and keep your key for updates. CompareHow koru relates to Capacitor and Expo.

How it works

You keep your web tools. koru packages the static files in webDir into an APK whose WebView serves them from a private HTTPS origin. A small JavaScript module gives your code access to Android features through a secure message channel. During development, koru dev serves the same files in your browser with web implementations of that API, and koru run installs the real app on a device.

The APK toolchain is written in Go with its standard library: DEX bytecode, the binary manifest, resources, ZIP packaging and the v2 signature. Builds are offline and take milliseconds. Your app works offline too; to call an HTTPS service, add the Internet permission.

Watch a terminal example
Create a project, build an APK and verify its signature
An earlier recording of the init, build and verify commands in a real session.

Before you distribute

koru is in development. It produces APKs for direct installation; it does not yet produce AABs for Google Play, and it does not build iOS apps. Recorded execution covers an Android 11 (API 30), x86_64 emulator. Test your app on the devices you plan to support. See tested compatibility.