ElementaryUI Runs Swift in the Browser at 586 Stars, and Needs Swift 6.4 and Warns of Sharp Edges

ElementaryUI lets developers write declarative web interfaces in Swift that compile to WebAssembly. It reached Hacker News on Oct. 30 with 121 points. Its site promises SwiftUI-style syntax and kilobyte bundles. Its README says it is not ready.

The repository had 586 stars, 17 forks and 12 watchers when I read it. The README marks it "Work In Progress" and calls it "an actively developed passion project in its early days." It adds: "Expect sharp edges, APIs may change, and things may break."

What the framework offers

The site lists @State, @Environment and @Reactive for reactivity, CSS-based animations, and a Vite dev server with hot reload. The sample on the page is a LoveCounter view. The site says it is "not affiliated with or endorsed by Apple Inc."

The licence is Apache 2.0 for the package. The README notes some code derives from Swift.org projects, and the bundled BrowserRuntime includes JavaScriptKit code under its own licence. The site itself states no licence.

What you need installed

Requirement	Detail
Compiler	Swift 6.4 or later
SDK	Matching Swift SDK for WebAssembly from swift.org
Release	No 0.1 yet; it is a roadmap item

Swift.org's WebAssembly guide says official Wasm SDKs began with Swift 6.2 and that you must "make sure to install and use an exactly matching Swift SDK version." Its sample uses Swift 6.4.2. It also says cross-compilation on Windows hosts is not supported yet.

The size claim

The site says "Full Embedded Swift support means kB-sized wasm bundles instead of MB." That is a feature statement. Neither the site nor the README gives a measured bundle size for any example app.

Swift.org describes Embedded Swift as an "experimental subset of the language" that yields much smaller binaries, shipped as a separate -embedded SDK. So the smallest bundles depend on a subset Swift's own maintainers label experimental, under a framework that labels itself early. Both caveats stack. For scepticism about size and speed claims without a number behind them, see how Lightpanda's 9x figure held up once the vendor's own agent test was read.

The toolchain has rough spots of its own. Swift.org says swift run delegates to WasmKit only in recent toolchain snapshots, that macOS needs the setup steps even with the latest Xcode, and that editors need the SDK ID set in .sourcekit-lsp/config.json. None of that is ElementaryUI's fault, but every user inherits it.

Browser-side tools that state a hard limit up front are the useful kind. editsqlite names its 4KB row limit in the headline; ElementaryUI names its early state in the README, which is what a cautious team needs.

Who is behind it

The README names no author. It sits in the elementary-swift organisation, and the sponsor link points to an account called sliemeobn. I am not treating that as an identification.

What to watch

The roadmap item is to "push a 0.1 out the door." Until then, version pinning is the only protection against the API changes the README promises. A measured bundle size from a real app would settle the main claim.