OpenFeature .NET SDK v3.0 – Breaking Changes, New Abstractions & Modernisation

[askpt]

🎉 OpenFeature .NET SDK v3.0

We're excited to share the roadmap for the next major release of the OpenFeature .NET SDK. This release focuses on improved modularity, cleaner abstractions for provider and hook authors, and modernized tooling.

📌 Track progress: Milestone 3.0.0

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🚀 What's Coming in v3.0

New Abstraction Libraries

To reduce coupling and improve the developer experience for provider and hook authors, we're introducing dedicated abstraction packages:

Package	Purpose	Issue
OpenFeature.Providers.Abstractions	Isolates provider-related abstractions from SDK churn, allowing provider developers to depend on a minimal, stable surface	#629
OpenFeature.Hooks.Abstractions	Isolates hook-related abstractions, providing clearer boundaries and easier versioning for hook contracts	#630
OpenFeature.Providers.DependencyInjection	A thin DI-friendly package exposing a builder API (OpenFeatureBuilder) for provider composition, without requiring a dependency on OpenFeature.Hosting	#587
OpenFeature.Hooks.DependencyInjection	A thin DI-friendly package for hook composition, mirroring the provider DI approach	TBD

Benefits:

• 🎯 Smaller dependency footprint – Provider/hook packages avoid bringing in infrastructure they don't use
• 🔒 Stability – Abstraction surfaces remain small and stable while the SDK evolves
• 🧩 Separation of concerns – OpenFeature users get the full Hosting experience; provider/hook authors get a minimal integration surface

⚠️ Breaking Change: This is a breaking change for existing providers and hooks. Migration guidance will be provided.

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Modernized Testing Infrastructure

We're upgrading our test framework to take advantage of the latest .NET ecosystem improvements:

Change	Description	Issue
xUnit v3 Upgrade	Update all xUnit dependencies to v3, including Reqnroll compatibility	#624
Microsoft Testing Platform (MTP)	Migrate to the new Microsoft Testing Platform for improved performance and tooling	#648

As part of this modernization, we'll be bumping tests to target net472 while keeping the library compatible with:

• net462 (for .NET Framework compatibility)
• netstandard2.0
• net8.0
• net9.0
• net10.0

This approach maintains backward compatibility while simplifying our tooling and CI pipeline.

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⚠️ Breaking Changes and Migration Guide

[To be added]

Application Author

Application Integrator

Provider/Hook Author

Integration Author

Library Author

[beeme1mr]

Hi @askpt, could you please add a list of breaking changes and a proposal how the the migration? We should try and keep that list up to date as we work on v3. Thanks for all your effort so far. This sounds like a great improvement.

[askpt]

Hey @beeme1mr! I will keep the discussion description updated with the latest on the v3 breaking changes.