Microsoft Adds Custom Copilot Agents for .NET Developers with C# and WinForms Experts

Microsoft and GitHub launched the first .NET-focused GitHub Copilot custom agents: C# Expert and WinForms Expert. These agents provide specialized assistance for C# best practices, async/await patterns, testing workflows, and Windows Forms UI development. Developers can activate them by placing agent instruction Markdown files in a `.github/agents` folder. The C# Expert enforces modern coding standards and minimizes code bloat, while the WinForms Expert prevents accidental modifications to `.Designer.cs` files. Both agents are experimental and represent a shift toward domain-specific AI assistance with persistent behavior profiles tied to repository context.