What is ReactiveUI?

ReactiveUI is a composable, cross-platform model-view-viewmodel framework for all .NET
platforms that is inspired by functional reactive programming, which is a paradigm that allows you
to abstract mutable state away from your user interfaces and express the idea around a feature in one readable place
and improve the testability of your application.

🔨 Get Started 🛍 Install Packages 🎞 Watch Videos 🎓 View Samples 🎤 Discuss ReactiveUI

Documentation

• [RxSchedulers](docs/RxSchedulers.md) - Using ReactiveUI schedulers without RequiresUnreferencedCode attributes

Book

There has been an excellent book written by our Alumni maintainer
Kent Boogart.

NuGet Packages

Install the following packages to start building your own ReactiveUI app. Note: some of the platform-specific
packages are required. This means your app won't perform as expected until you install the packages properly. See
the Installation docs page for more info.

| Platform | ReactiveUI Package | NuGet |
|---------------|--------------------------------------|------------------------------|
| .NET Standard | [ReactiveUI][CoreDoc] | [![CoreBadge]][Core] |
| Any | [ReactiveUI.SourceGenerators][SGDoc] | [![SGBadge]][SG] |
| Unit Testing | [ReactiveUI.Testing][TestDoc] | [![TestBadge]][Test] |
| WPF | [ReactiveUI.WPF][WpfDoc] | [![WpfBadge]][Wpf] |
| WinUI | [ReactiveUI.WinUI][WinUiDoc] | [![WinUiBadge]][WinUi] |
| MAUI | [ReactiveUI.Maui][MauiDoc] | [![MauiBadge]][Maui] |
| Windows Forms | [ReactiveUI.WinForms][WinDoc] | [![WinBadge]][Win] |
| AndroidX | [ReactiveUI.AndroidX][DroDoc] | [![DroXBadge]][DroX] |
| Blazor | [ReactiveUI.Blazor][BlazDoc] | [![BlazBadge]][Blaz] |
| Platform Uno | [ReactiveUI.Uno][UnoDoc] | [![UnoBadge]][Uno] |
| Platform Uno | [ReactiveUI.Uno.WinUI][UnoWinUiDoc] | [![UnoWinUiBadge]][UnoWinUi] |
| Avalonia | [ReactiveUI.Avalonia][AvaDoc] | [![AvaBadge]][Ava] |
| Any | [ReactiveUI.Validation][ValDocs] | [![ValBadge]][ValCore] |
| Any | [ReactiveUI.Extensions][ExtDocs] | [![ExtBadge]][Ext] |

Choosing a distribution: ReactiveUI.Primitives or System.Reactive

ReactiveUI ships in two interchangeable distributions with an identical public API, both built on the same
ReactiveUI.Primitives engine and the same high-performance custom schedulers/sinks. The only difference is which
reactive interop types appear in the public API — so you pick a distribution, you don't rewrite code:

| You want… | Reference these packages | Public reactive types |
|---|---|---|
| The new, lighter default (no System.Reactive dependency) | ReactiveUI, ReactiveUI.Wpf, ReactiveUI.WinForms, ReactiveUI.WinUI, ReactiveUI.Maui, ReactiveUI.Blazor, ReactiveUI.AndroidX, … | ReactiveUI.Primitives — RxVoid, ISequencer, Signal |
| Drop-in interop with existing System.Reactive code | ReactiveUI.Reactive, ReactiveUI.Wpf.Reactive, ReactiveUI.WinForms.Reactive, ReactiveUI.WinUI.Reactive, ReactiveUI.Maui.Reactive, ReactiveUI.Blazor.Reactive, … | System.Reactive — Unit, IScheduler |

The .Reactive family is not "old ReactiveUI" — it runs on the exact same Primitives engine and custom
schedulers as the default and simply surfaces System.Reactive.Unit/IScheduler (and Subject) so it composes
with code that already uses System.Reactive.

The default distribution drops the System.Reactive dependency for a smaller closure and a better trimming/AOT
story, and is markedly faster on the hottest MVVM paths — in representative micro-benchmarks roughly 3–4× faster
on WhenAnyValue/ToProperty subscribe and emit, with 5–13× less allocation (for example WhenAnyValue emit
drops from ~6.8 MB to ~0.5 MB per run, and ToProperty construction from ~7.3 µs to ~1.0 µs). The fast schedulers
now live in ReactiveUI.Primitives and back both distributions.

If you take the default packages, note the public reactive types change: IScheduler → ISequencer,
System.Reactive.Unit → RxVoid, and Subject/BehaviorSubject → Signal/BehaviorSignal. To upgrade
with zero source changes, reference the matching *.Reactive packages instead — they keep IScheduler, Unit
and Subject.

Core routing (RoutingState, IScreen, RoutedViewHost) stays in the main package, but the DynamicData change-set
routing/collection/auto-persist helpers now live in a separate ReactiveUI.Routing package (ReactiveUI.Routing.Reactive
for the System.Reactive flavor), so core no longer depends on DynamicData. Add ReactiveUI.Routing if you use those
extensions.

[Core]: https://www.nuget.org/packages/ReactiveUI/

[CoreBadge]: https://img.shields.io/nuget/v/ReactiveUI.svg

[CoreDoc]: https://reactiveui.net/docs/getting-started/installation/

[SG]: https://www.nuget.org/packages/ReactiveUI.SourceGenerators/

[SGDoc]: https://reactiveui.net/docs/handbook/view-models/boilerplate-code

[SGBadge]: https://img.shields.io/nuget/v/ReactiveUI.SourceGenerators.svg

[Test]: https://www.nuget.org/packages/ReactiveUI.Testing/

[TestBadge]: https://img.shields.io/nuget/v/ReactiveUI.Testing.svg

[TestDoc]: https://reactiveui.net/docs/handbook/testing/

[Wpf]: https://www.nuget.org/packages/ReactiveUI.WPF/

[WpfBadge]: https://img.shields.io/nuget/v/ReactiveUI.WPF.svg

[WpfDoc]: https://reactiveui.net/docs/getting-started/installation/windows-presentation-foundation

[WinUi]: https://www.nuget.org/packages/ReactiveUI.WinUI/

[WinUiBadge]: https://img.shields.io/nuget/v/ReactiveUI.WinUI.svg

[WinUiDoc]: https://reactiveui.net/docs/getting-started/installation/universal-windows-platform

[Maui]: https://www.nuget.org/packages/ReactiveUI.Maui/

[MauiBadge]: https://img.shields.io/nuget/v/ReactiveUI.Maui.svg

[MauiDoc]: https://blog.jetbrains.com/dotnet/2020/09/18/xamarin-maui-and-the-reactive-mvvm-between-them-webinar-recording/

[Win]: https://www.nuget.org/packages/ReactiveUI.WinForms/

[WinEvents]: https://www.nuget.org/packages/ReactiveUI.Events.WinForms/

[WinBadge]: https://img.shields.io/nuget/v/ReactiveUI.WinForms.svg

[WinDoc]: https://reactiveui.net/docs/getting-started/installation/windows-forms

[DroX]: https://www.nuget.org/packages/ReactiveUI.AndroidX/

[DroXBadge]: https://img.shields.io/nuget/v/ReactiveUI.AndroidX.svg

[DroDoc]: https://reactiveui.net/docs/getting-started/installation/

[Uno]: https://www.nuget.org/packages/ReactiveUI.Uno/

[UnoBadge]: https://img.shields.io/nuget/v/ReactiveUI.Uno.svg

[UnoDoc]: https://reactiveui.net/docs/getting-started/installation/uno-platform

[UnoWinUi]: https://www.nuget.org/packages/ReactiveUI.Uno.WinUI/

[UnoWinUiBadge]: https://img.shields.io/nuget/v/ReactiveUI.Uno.WinUI.svg

[UnoWinUiDoc]: https://reactiveui.net/docs/getting-started/installation/uno-platform

[Blaz]: https://www.nuget.org/packages/ReactiveUI.Blazor/

[BlazBadge]: https://img.shields.io/nuget/v/ReactiveUI.Blazor.svg

[BlazDoc]: https://www.reactiveui.net/docs/getting-started/installation/blazor

[Ava]: https://www.nuget.org/packages/ReactiveUI.Avalonia/

[AvaBadge]: https://img.shields.io/nuget/v/ReactiveUI.Avalonia.svg

[AvaDoc]: https://reactiveui.net/docs/getting-started/installation/avalonia

[EventsDocs]: https://reactiveui.net/docs/handbook/events/

[ValCore]: https://www.nuget.org/packages/ReactiveUI.Validation/

[ValBadge]: https://img.shields.io/nuget/v/ReactiveUI.Validation.svg

[ValDocs]: https://reactiveui.net/docs/handbook/user-input-validation/

[Ext]: https://www.nuget.org/packages/ReactiveUI.Extensions/

[ExtBadge]: https://img.shields.io/nuget/v/ReactiveUI.Extensions.svg

[ExtDocs]: https://reactiveui.net/

Sponsorship

The core team members, ReactiveUI contributors and contributors in the ecosystem do this open-source work in their free
time. If you use ReactiveUI, a serious task, and you'd like us to invest more time on it, please donate. This project
increases your income/productivity too. It makes development and applications faster and it reduces the required
bandwidth.

Become a sponsor.

Migration from Xamarin and .NET 8 MAUI

Xamarin Users

As of May 2024, Microsoft ended support for Xamarin per
their support policy. ReactiveUI has removed
support for legacy Xamarin platforms in favor of modern .NET MAUI. For Xamarin projects:

• Xamarin.Forms → Migrate to MAUI and use ReactiveUI.Maui
• Xamarin.Android → Migrate to MAUI Android or use ReactiveUI.AndroidX for native Android
• Xamarin.iOS/Mac → Migrate to MAUI iOS/Mac Catalyst

For guidance on migrating from Xamarin to MAUI, see the official migration documentation.

MAUI Users

ReactiveUI supports .NET 9 and .NET 10 for MAUI platforms:

• net10.0-android / net9.0-android
• net10.0-ios / net9.0-ios
• net10.0-maccatalyst / net9.0-maccatalyst
• net10.0-windows10.0.19041.0 / net9.0-windows10.0.19041.0

Non-MAUI net8.0 library targets remain fully supported.

Examples

Platform-specific sample applications are included in [src/examples/](src/examples/):

| Sample | Platform | Description |
|---------------------------------------------------------------------------------|---------------|--------------------------------------------------------------------|
| [ReactiveUI.Samples.Wpf](src/examples/ReactiveUI.Samples.Wpf) | WPF | Login form with reactive bindings, PasswordBox event marshaling |
| [ReactiveUI.Samples.Winforms](src/examples/ReactiveUI.Samples.Winforms) | WinForms | Login form with IViewFor, programmatic UI layout |
| [ReactiveUI.Samples.Maui](src/examples/ReactiveUI.Samples.Maui) | MAUI | Cross-platform login with Shell navigation, ReactiveContentPage |
| [ReactiveUI.Builder.WpfApp](src/examples/ReactiveUI.Builder.WpfApp) | WPF | Multi-instance chat app with routing, suspension, and network sync |
| [ReactiveUI.Builder.BlazorServer](src/examples/ReactiveUI.Builder.BlazorServer) | Blazor Server | Chat app with server-side Blazor and reactive components |

All samples target .NET 10, use RxAppBuilder for initialization, and demonstrate WhenActivated, Bind/
BindCommand, and proper subscription disposal.

This is how we use the donations:

• Allow the core team to work on ReactiveUI
• Thank contributors if they invested a large amount of time in contributing
• Support projects in the ecosystem

Support

If you have a question, please see if any discussions in
our GitHub issues
or Stack Overflow have already answered it.

If you want to discuss something or just need help, here is our Slack room, where there
are always individuals looking to help out!

Please do not open GitHub issues for support requests.

Contribute

ReactiveUI is developed under an OSI-approved open source license, making it freely usable and distributable, even for
commercial use.

If you want to submit pull requests please first open
a GitHub issue to discuss. We are first time PR
contributors friendly.

See Contribution Guidelines for further information how to contribute changes.

Core Team

Glenn Watson
Melbourne, Australia




Chris Pulman
United Kingdom






Rodney Littles II
Texas, USA




Colt Bauman
South Korea

Alumni Core Team

The following have been core team members in the past.

Geoffrey Huntley
Sydney, Australia




Kent Boogaart
Brisbane, Australia




Olly Levett
London, United Kingdom






Anaïs Betts
San Francisco, USA




Brendan Forster
Melbourne, Australia




Claire Novotny
New York, USA




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