A compact, allocation-conscious reactive programming library for .NET built on IObservable<T>. It covers the common Rx operators, scheduling and state without a runtime dependency on System.Reactive, and is designed for trimming and native AOT.
Latest release v9.0.0 — 9.0.0 · 3 Oct 2026
3 files for GitHub Copilot, Codex, OpenCode and Claude Code: Primitives copilot-instructions.md, Primitives AGENTS.md, Primitives CLAUDE.md — 2,328 tokens loaded in every session.
.github/copilot-instructions.md A 33 tok AGENTS.md A 26 tok CLAUDE.md A 2,269 tok These files are reactiveui/Primitives's own configuration — they tell GitHub Copilot, Codex, OpenCode and Claude Code how to work on this repository, so they are not mods to install elsewhere. Copy one as a starting point and replace the parts that are about this project.