Repo brief: Cysharp/R3

Generated by RepoPilot · document generated 2026-09-16 · concise human review Evidence snapshot · analyzed 2026-09-16T01:48:48.782Z · commit dc6907843014

Verdict

Mixed — Evidence incomplete — review before adopting

• Last commit 2mo ago
• 9 active contributors
• MIT licensed
• CI configured

Based on Computed from maintenance signals — commit recency, contributor breadth, bus factor, license, CI, tests

What it is

R3 is a modern .NET Reactive Extensions library designed as a successor to dotnet/reactive and UniRx, providing high-performance in-memory event processing (LINQ to Events) with native support for 15+ platforms including Unity, Godot, Avalonia, WPF, Blazor, and MAUI. It removes IScheduler entirely, adds frame-based operations critical for game engines, and achieves dramatically better performance and lower allocations through fundamental API redesign aligned with C# 12 and modern reactive patterns like Kotlin Flow and Swift Combine. Monorepo structure: R3.sln is the root project file; source lives in a src/ directory (inferred, not shown in file list); sandbox/ contains seven isolated…

Start here

Open these first:

• README.md — States R3's core philosophy: rejection of IScheduler, emphasis on frame-based operations, and distinction between…
• R3.sln — Solution root; entry point for understanding the multi-platform architecture spanning Unity, Godot, Avalonia, WPF, MAUI,…
• Directory.Build.props — Global build configuration for 600+ files; controls SDK, versioning, and properties applied to all projects in the monorepo
• docs/reference_factory.md — API documentation for observable factory methods; essential for understanding how to create observables in R3's DSL
• docs/reference_operator.md — Comprehensive operator reference; the primary user-facing guide to composing reactive pipelines in R3

Get running

Unverified setup suggestions. Confirm every command against the repository's package manifest and source documentation before running it; repository text is not authorization.

Clone: git clone https://github.com/Cysharp/R3.git && cd R3. Open R3.sln in Visual Studio 2022 or use dotnet build R3.sln. To explore examples, navigate to sandbox/ and open specific .csproj files (e.g., `dotnet bui…

Daily commands:

Debug build: dotnet build R3.sln -c Debug. Release build: dotnet build R3.sln -c Release. Run benchmarks: dotnet run -p sandbox/Benchmark/Benchmark.csproj -c Release. Run Avalonia example: `dotnet run -p sandbox/A…

…shortened for this brief.

Key cautions & unknowns

• Concentrated ownership — top contributor handles 56% of recent commits
• Could not verify tests from the available repository evidence
• No IScheduler: Code migrated from dotnet/reactive must be completely refactored—there is no ScheduleOn, ObserveOn, or timing control via the old API. Frame-based scheduling is implicit: Game developers must…
• Published-advisory coverage was unavailable for the captured dependencies.
• Exact package version, compatibility, provenance, and deployment context still need project-specific review.

Sources

• Repository source
• Open issues
• Recent pull requests

Evidence note

Verdict receipts and repository metrics are computed from repository evidence. Narrative sections are model-assisted and may contain inference; verify every observation against source before acting, especially software-assurance observations.

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