Project Briefing
AsyncCombine is a lightweight Swift library that brings familiar Combine-style patterns like sink, assign, and store(in:) into the modern async/await world.
Instead of building on top of Combine’s publishers, AsyncCombine uses AsyncSequence and Swift Concurrency directly. This gives you a clean, dependency-free way to react to values over time, integrate with Swift’s new @Observable / Observation framework, and bind state into your UI - all without pulling in Combine or juggling multiple reactive abstractions.
At the heart of the library is CurrentValueRelay, a replay-1 async primitive inspired by Combine’s CurrentValueSubject. It gives you a simple, portable way to bridge stateful streams between your domain logic and your presentation layer, while still playing nicely with async/await and structured concurrency.
AsyncCombine handles the plumbing so you can focus on your app’s behaviour, not your glue code.
AsyncCombine will:
- Provide familiar operators like
sink,assign, andstore(in:)for AsyncSequence-based streams. - Offer
CurrentValueRelay, a replay-1 async primitive for stateful, observable values. - Make it easy to react to changes in
@Observablemodels using Swift’s Observation framework. - Help you bind async state to UI across platforms (SwiftUI, UIKit, AppKit) without needing Combine.
- Let you centralise and manage the lifetime of async subscriptions in a predictable way.
- Stay focused and lightweight — no global runtime, no magic, just small composable tools built on async/await.
Technical Details
- Written in pure Swift and built on Swift Concurrency (AsyncSequence, Task, etc.).
- Designed to work with Swift 5.10 and Swift 6 toolchains.
- Suitable for iOS, macOS, watchOS, and tvOS apps that use async/await.
- Integrates with Swift’s Observation framework to turn @Observable models into async streams.
- Distributed via Swift Package Manager.
- Open source and developed in the open on GitHub, with unit tests to help ensure correctness and stability.