--- title: "ASP0008: Do not use ConfigureWebHost with WebApplicationBuilder.Host" description: "Learn about analysis rule ASP0008: Do not use ConfigureWebHost with WebApplicationBuilder.Host" author: safia monikerRange: '>= aspnetcore-7.0' ms.author: safia ms.date: 09/23/2022 uid: diagnostics/asp0008 --- # ASP0008: Do not use ConfigureWebHost with WebApplicationBuilder.Host | | Value | |-|-| | **Rule ID** |ASP0008| | **Category** |Usage| | **Fix is breaking or non-breaking** |Non-breaking| ## Cause `ConfigureWebHost` can't be used with the `Host` property on `WebApplicationBuilder`. ## Rule description The `WebApplicationBuilder` doesn't support configuring the `WebHost` before build using the `ConfigureWebHost` extension method. ```csharp var builder = WebApplication.CreateBuilder(args); builder.Host.ConfigureWebHost(webHostBuilder => { webHostBuilder.UseContentRoot(Path.Combine(Directory.GetCurrentDirectory(), "myContentRoot")); }); var app = builder.Build(); app.Run(); ``` ## How to fix violations To fix a violation of this rule, configure the `WebHost` directly on the `WebApplicationBuilder`. For example, instead of setting the content root path via `ConfigureWebHost`. ```csharp var builder = WebApplication.CreateBuilder(args); builder.Host.ConfigureWebHost(webHostBuilder => { webHostBuilder.UseContentRoot(Path.Combine(Directory.GetCurrentDirectory(), "myContentRoot")); }); var app = builder.Build(); app.Run(); ``` Configure the content root path directly on the `WebApplicationBuilder.WebHost`. ```csharp var builder = WebApplication.CreateBuilder(args); builder.WebHost.UseContentRoot(Path.Combine(Directory.GetCurrentDirectory(), "foobar")); var app = builder.Build(); app.Run(); ``` ## When to suppress warnings Do ***not*** suppress a warning from this rule. A misconfigured application can result in unexpected behavior at runtime.