Client library comparison

This table shows which capabilities each Kizuna client library exposes, with a link from every supported cell to the reference page that documents it.

Capability	JavaScript	React	Vue	Expo / React Native	Swift	Kotlin
Local reads and writes	Yes	Yes	Yes	JS client	Yes	Yes
Supabase-style filters and modifiers	Yes	JS client	JS client	JS client	Yes	Yes
Field transforms	Yes	JS client	JS client	JS client	Yes	Yes
Atomic write batches	No	No	No	No	No	No
Journal of rejected writes	Yes	Yes	Yes	JS client	Yes	Yes
Journal of overwritten columns	Yes	Yes	Yes	JS client	Yes	Yes
Attachments	Yes, with fileStore	Yes	Yes	Yes, with Expo file store	Yes, with attachmentRoot	Yes, with attachmentRoot
Sync status hook or composable	No; getSyncHealth instead	Yes	Yes	React hooks	No; scheduler health() instead	No; scheduler health() instead
Automatic sync loop	Yes	JS client	JS client	JS client	App builds the scheduler	App builds the scheduler
Realtime wake-up	Yes	JS client	JS client	JS client	Port; app writes the adapter	Port; app writes the adapter
Session refresh on foreground	Yes	JS client	JS client	Yes	Pass a refreshSession closure	Pass an Android foreground source
Browser tabs sharing one database	Yes, in the browser	JS client	JS client	On Expo web	Not applicable	Not applicable
How the Rust engine runs	WebAssembly worker or N-API	JS client	JS client	UniFFI; WebAssembly on web	UniFFI	UniFFI

How to read the table#

React, Vue, and Expo / React Native wrap the JavaScript app client, so "JS client" means the capability comes from that client unchanged, and "React hooks" means an Expo app uses the React package, as it can wherever the React column has a hook. On iOS and Android the Expo / React Native column needs a development build, because Expo Go cannot load the engine, as Expo: Rust engine explains. Swift and Kotlin have no hooks: a native app subscribes to events with on and reads the state of its sync loop from the host scheduler it builds next to the client. A native app has no browser tabs, so the tab row reads "Not applicable" for Swift and Kotlin. The engine and the wire protocol carry atomic batches, but no app client exposes a way to create one, and Offline writes recommends one server-side operation for an all-or-nothing rule instead. Supported query operators lists the filters and modifiers method by method.

Related reference#

• JavaScript: Introduction
• React: Introduction
• Vue: Introduction
• Expo: Introduction
• Swift: Introduction
• Kotlin: Introduction
• Comparison with alternatives
• FAQ