Convert Blazor Server App to Blazor Web App

This skill helps an agent convert a pre-.NET 8 Blazor Server app into a .NET 8+ Blazor Web App. The old hosting model uses AddServerSideBlazor/MapBlazorHub with a _Host.cshtml Razor Page as the entry point. The new Blazor Web App model uses AddRazorComponents/MapRazorComponents with an App.razor root component, enabling per-component render modes, enhanced navigation, streaming rendering, and other .NET 8+ features. The converted app uses InteractiveServer render mode to preserve existing interactive behavior.

When to Use

• Migrating a Blazor Server app from .NET 6 or .NET 7 to .NET 8+
• App currently uses AddServerSideBlazor() and MapBlazorHub() in Program.cs (or Startup.cs)
• App uses Pages/_Host.cshtml (or _Host.razor) as the host page with Component Tag Helpers
• Want to adopt new Blazor Web App features while keeping interactive server rendering

When Not to Use

• The app already uses AddRazorComponents and MapRazorComponents. It is already a Blazor Web App, no conversion is needed. Stop here and tell the user the app is already using the Blazor Web App model.
• Blazor WebAssembly or hosted Blazor WebAssembly app, these have a different migration path
• The app should stay on the legacy Blazor Server hosting model (just update TFM and packages)
• The app targets .NET Framework, it must be migrated to .NET first

Inputs

Input	Required	Description
Blazor Server project	Yes	The .csproj and source files of the Blazor Server app
Target framework	Yes	.NET 8 or later (e.g., net8.0, net9.0, net10.0)
Program.cs or Startup.cs	Yes	The app's service and middleware configuration
_Host.cshtml location	Recommended	Usually Pages/_Host.cshtml; may be _Host.razor in some projects

Workflow