C# SDK Only Ships net8.0 — No Official .NET 9 or .NET 10 Target #499
Description
C# SDK Only Ships net8.0 — No Official .NET 9 or .NET 10 Target
Severity: Documentation gap
Component: Microsoft.AI.Foundry.Local NuGet package v0.8.2.1
Install command: dotnet add package Microsoft.AI.Foundry.Local
The NuGet package only ships a single target framework:
lib/
net8.0/
Microsoft.AI.Foundry.Local.dll
No net9.0 or net10.0 TFM is included. By contrast, the companion package Microsoft.Agents.AI.OpenAI (v1.0.0-rc3) ships net8.0, net9.0, net10.0, net472, and netstandard2.0.
Compatibility Testing
| Target Framework | Build | Run | Notes |
|---|---|---|---|
| net8.0 | ✅ | ✅ | Officially supported — used in workshop samples |
| net9.0 | ✅ | ❌ | Builds via forward-compat, but .NET 9 runtime not available on test machine (only 8.0.24 and 10.0.3 installed) |
| net10.0 | ✅ | ✅ | Builds and runs via forward-compat with .NET 10.0.3 runtime |
The net8.0 assembly loads on newer runtimes through .NET's forward-compatibility mechanism, so the build succeeds. However, this is undocumented and untested by the SDK team.
Why the Samples Target net8.0
- It is the only officially shipped TFM in the Foundry Local NuGet package
- .NET 8 is the current LTS release — the broadest install base
- .NET 9 runtime is not commonly installed — .NET 9 reached end-of-life (STS), and many machines skip directly from 8 to 10
- .NET 10 (preview/RC) is too new to target in a workshop that should work for everyone
Expected: Future SDK releases should consider adding net9.0 and net10.0 TFMs alongside net8.0 to match the pattern used by Microsoft.Agents.AI.OpenAI and to provide validated support for newer runtimes.
Sample code to validate https://github.com/microsoft-foundry/Foundry-Local-Lab