An advanced, composable, functional reactive model-view-viewmodel framework for all .NET platforms that is inspired by functional reactive programming. ReactiveUI allows you to abstract mutable state away from your user interfaces, express the idea around a feature in one readable place and improve the testability of your application.
This report presents the forensic synthetic code analysis of reactiveui/ReactiveUI, a C# project with 8,508 GitHub stars. SynthScan v2.0 examined 268,122 lines of code across 1695 source files, recording 1156 pattern matches distributed across 6 syntactic categories. The overall adjusted score of 4.3 places this repository in the Likely human-written band.
The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).
This chart maps the temporal evolution of the adjusted synthetic code score across successive scan runs. An upward trajectory indicates ongoing incorporation of AI-generated code or expanding LLM-assisted scaffolding; a stable or declining trajectory may reflect active human refactoring, code removal, or the adoption of stricter authorship policies. The dashed secondary line (right axis) independently tracks total raw pattern hit count, which can diverge from the normalised score when codebase size changes significantly between scans.
Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.
This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.
The scanner identified 1156 distinct pattern matches across 6 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | tools/generate-publicapi.sh | 1 | #!/usr/bin/env bash | COMMENT |
| LOW | tools/generate-publicapi.sh | 21 | # MSBuildWorkspace and only writes its own PublicAPI/<tfm>/ files — so the pairs run | COMMENT |
| LOW | .github/workflows/sonarcloud.yml | 21 | # Coverage exclusions (sonar.coverage.exclusions) — code the Sonar scan cannot execute, so counting it | COMMENT |
| LOW | src/ReactiveUI.Testing/TestSequencer.cs | 21 | /// <summary>Initializes a new instance of the <see cref="TestSequencer"/> class.</summary> | COMMENT |
| LOW | src/ReactiveUI.Testing/AppBuilderTestBase.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Testing/SchedulerExtensions.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Testing/SchedulerExtensions.cs | 61 | } | COMMENT |
| LOW | src/ReactiveUI.Testing/MessageBusExtensions.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …ReactiveUI.Testing.Reactive/TestSchedulerExtensions.cs | 21 | /// <returns>Timespan for virtual scheduler to use.</returns> | COMMENT |
| LOW | …ReactiveUI.Testing.Reactive/TestSchedulerExtensions.cs | 41 | /// conjunction with CreateHotObservable or CreateColdObservable. | COMMENT |
| LOW | …c/ReactiveUI.Winforms/CreatesWinformsCommandBinding.cs | 21 | COMMENT | |
| LOW | …c/ReactiveUI.Winforms/CreatesWinformsCommandBinding.cs | 81 | /// <summary> | COMMENT |
| LOW | …c/ReactiveUI.Winforms/CreatesWinformsCommandBinding.cs | 281 | ? EmptyDisposable.Instance | COMMENT |
| LOW | src/ReactiveUI.Winforms/ContentControlBindingHook.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …c/ReactiveUI.Winforms/ReactiveUserControlNonGeneric.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Winforms/ViewModelViewHost.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Winforms/ViewModelViewHost.Designer.cs | 1 | //------------------------------------------------------------------------------ | COMMENT |
| LOW | src/ReactiveUI.Winforms/ReactiveUserControl.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Winforms/ReactiveUserControl.Designer.cs | 1 | #if REACTIVE_SHIM | COMMENT |
| LOW | …eUI.Winforms/ReactiveUserControlNonGeneric.Designer.cs | 1 | #if REACTIVE_SHIM | COMMENT |
| LOW | src/ReactiveUI.Winforms/RoutedViewHost.Designer.cs | 1 | #if REACTIVE_SHIM | COMMENT |
| LOW | src/ReactiveUI.Core/UnhandledErrorException.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/Interactions/InteractionContext.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/Interactions/InteractionContext.cs | 21 | /// <example> | COMMENT |
| LOW | src/ReactiveUI.Core/Interactions/IInteractionContext.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/Interactions/IInteractionContext.cs | 21 | /// <code language="csharp"> | COMMENT |
| LOW | src/ReactiveUI.Core/Interactions/IOutputContext.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …iveUI.Core/Registration/DependencyResolverRegistrar.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …/ReactiveUI.Core/EventHandlers/LocalizableAttribute.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/Mixins/DependencyResolverMixins.cs | 81 | /// <summary> | COMMENT |
| LOW | …/ReactiveProperty/SingletonPropertyChangedEventArgs.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …eactiveProperty/SingletonDataErrorsChangedEventArgs.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …eactiveUI.Core/Activation/IActivationForViewFetcher.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …eactiveUI.Core/Activation/IActivationForViewFetcher.cs | 21 | /// <code language="csharp"> | COMMENT |
| LOW | …eactiveUI.Core/Activation/IActivationForViewFetcher.cs | 41 | /// Determines the priority that the Activation View Fetcher | COMMENT |
| LOW | src/ReactiveUI.Core/Internal/StartWithObservable.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/Internal/TaskObservable.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …ore/ObservableForProperty/INPCObservableForProperty.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …ore/ObservableForProperty/INPCObservableForProperty.cs | 81 | : Signal.Silent<IObservedChange<object?, object?>>(); | COMMENT |
| LOW | src/ReactiveUI.Core/ReactiveObject/IExtensionState.cs | 21 | COMMENT | |
| LOW | src/ReactiveUI.Core/ReactiveObject/IReactiveObject.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/ChangeSets/CollectionChanged.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …ctiveUI.Core/ChangeSets/CollectionChangedExtensions.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/ChangeSets/ReactiveChangeSet{T}.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/ChangeSets/IReactiveChangeSet{T}.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/ChangeSets/ReactiveChangeReason.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/ChangeSets/ReactiveChange.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …c/ReactiveUI.Core/View/ViewLocatorNotFoundException.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | …c/ReactiveUI.Core/View/ViewLocatorNotFoundException.cs | 21 | /// <example> | COMMENT |
| LOW | …c/ReactiveUI.Core/View/ViewLocatorNotFoundException.cs | 61 | #if !NET8_0_OR_GREATER | COMMENT |
| LOW | src/ReactiveUI.Core/View/SingleInstanceViewAttribute.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/View/ViewMappingBuilder.cs | 61 | /// <param name="factory">Factory function that creates the view.</param> | COMMENT |
| LOW | src/ReactiveUI.Core/View/ViewLocator.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/View/ViewLocator.cs | 21 | /// </remarks> | COMMENT |
| LOW | src/ReactiveUI.Core/View/DefaultViewLocator.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| LOW | src/ReactiveUI.Core/View/DefaultViewLocator.cs | 21 | /// All view-viewmodel associations must be registered at application startup. | COMMENT |
| LOW | src/ReactiveUI.Core/View/DefaultViewLocator.cs | 41 | /// <summary>Lock object for synchronizing writes to _mappings.</summary> | COMMENT |
| LOW | src/ReactiveUI.Core/View/DefaultViewLocator.cs | 61 | /// <summary>Registers a direct mapping from a view model type to a view factory using the default contract.</summar | COMMENT |
| LOW | src/ReactiveUI.Core/View/DefaultViewLocator.cs | 161 | /// <summary>Resolves a view for a view model type known at compile time. Fully AOT-compatible.</summary> | COMMENT |
| LOW | src/ReactiveUI.Core/View/ViewContractAttribute.cs | 1 | // Copyright (c) 2009-2026 .NET Foundation and Contributors. All rights reserved. | COMMENT |
| 1086 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | src/ReactiveUI.Winforms/ViewModelViewHost.Designer.cs | 3 | // This code was generated by a tool. | COMMENT |
| HIGH | …ests/ReactiveUI.Tests/Properties/Resources.Designer.cs | 3 | // This code was generated by a tool. | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | tools/generate-publicapi.sh | 24 | # Usage: | COMMENT |
| LOW | src/ReactiveUI/Platforms/mac/AutoSuspendHelper.cs | 27 | /// Example usage: | COMMENT |
| LOW | src/ReactiveUI/Platforms/android/AutoSuspendHelper.cs | 24 | /// Example usage: | COMMENT |
| LOW | src/ReactiveUI.Wpf.Shared/AutoSuspendHelper.cs | 23 | /// Example usage: | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | …activeUI.Shared/ReactiveCommand/ReactiveCommandBase.cs | 48 | /// As discussed above, you are under no obligation to somehow incorporate this into your <c>canExecute</c> observable | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | …c/ReactiveUI.Wpf.Shared/TransitioningContentControl.cs | 628 | // Do some special handling of particular transitions so that we get nice smooth transitions that utilize the si | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | …BlazorServer/Components/Layout/ReconnectModal.razor.js | 11 | function handleReconnectStateChanged(event) { | CODE |
| LOW | …BlazorServer/Components/Layout/ReconnectModal.razor.js | 59 | async function retryWhenDocumentBecomesVisible() { | CODE |