KetoyVM is a Kotlin execution runtime for Android that runs Ketoy Bytecode compiled from plain Kotlin source, including Jetpack Compose, coroutines, ViewModels, and Navigation, delivered as a .ktx bundle. Hilt and Room stay in the host app; KetoyVM exposes their functions for new features because updating them requires a Play Store release.

How do I ship Android app updates in seconds?

Write Kotlin, run ./gradlew ketoyBundle, upload the resulting .ktx to Ketoy Cloud, and the KetoyRuntime on every device fetches and executes the new bundle in about 60 seconds without Play Store review or binary split.

Is KetoyVM a server-driven UI framework?

KetoyVM is stronger than a server-driven UI DSL: it executes real Kotlin on device with native Jetpack Compose rendering, real coroutine semantics and real ViewModel lifecycles, so you keep full-surface Compose without a custom schema.

Is this like CodePush or Hermes?

What Hermes is to React Native's JavaScript, KetoyVM is to Kotlin and Compose: a purpose-built execution runtime, not a script interpreter wedged into a different stack.

Structured concurrency across the bundle boundary.

A coroutine started inside a bundle must honor the host's lifecycle. That sentence hides a quarter of engineering.

The obvious model is to give the bundle its own CoroutineScope, rooted in the host viewModelScope or equivalent. The obvious model is also wrong: cancellation propagates the opposite direction across the seam, and the bundle cannot see the host's Job to install a handler on it.

§ 01 — TWO JOBS, ONE HIERARCHYHow we bridge the boundary

The runtime exposes a single BundleScope that wraps two Jobs: a host-side root and a bundle-side local. The host root cancels the bundle job; bundle work never leaks upward. Cancellation is idempotent and immediate.

PITFALL

If you ever see a coroutine outliving its host, check that the bundle was unloaded through KetoyRuntime.unload() and not via a bare reference drop. We documented this loudly, but it bites people.

— I.M. · Concurrency, Apr 11 2026

Isabel Moreau

Works on coroutines, structured concurrency, and the bundle boundary.