# Configure Auth

Add authentication and authorization to a Blazor Web App, accounting for the app's...

- Repository: https://github.com/dotnet/skills (5787 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add dotnet/skills --skill configure-auth -g -a claude-code -y`
Codex: `npx skills add dotnet/skills --skill configure-auth -g -a codex -y`
Cursor: `npx skills add dotnet/skills --skill configure-auth -g -a cursor -y`
Gemini CLI: `npx skills add dotnet/skills --skill configure-auth -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add dotnet/skills`

## Description

Add authentication and authorization to a Blazor Web App, accounting for the app's render mode. USE WHEN the user needs [Authorize] on pages, AuthorizeView, role or policy-based access, login/logout Identity pages, or AuthenticationStateProvider. Also USE WHEN auth state is null after WebAssembly loads, SignInManager throws in an interactive component, NotAuthorized content never renders in static SSR, or HttpContext.User is null in an interactive component. DO NOT USE for general component authoring (see author-component), for prerendering concerns unrelated to auth (see support-prerendering), or for managing non-auth cascading state (see coordinate-components).

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Configure Auth

## Step 1, Read AGENTS.md

Read `AGENTS.md` at the workspace root for the project's interactivity mode and scope before making changes.

## Step 2, Register auth services in Program.cs

```csharp
// Program.cs (server project)
builder.Services.AddCascadingAuthenticationState();
builder.Services.AddAuthorization();
```

For ASP.NET Core Identity add the Identity services:

```csharp
builder.Services.AddAuthentication(options =>
{
    options.DefaultScheme = IdentityConstants.ApplicationScheme;
    options.DefaultSignInScheme = IdentityConstants.ExternalScheme;
})
.AddIdentityCookies();

builder.Services.AddIdentityCore<ApplicationUser>()
    .AddRoles<IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddSignInManager()
    .AddDefaultTokenProviders();
```

## Step 3, Wire App.razor for auth and render mode

The `App.razor` component must use `AuthorizeRouteView` and conditionally apply the render mode so that pages excluded from interactive routing render statically.

```razor
<!DOCTYPE html>
<html>
<head>
    <HeadOutlet @rendermode="RenderModeForPage" />
</head>
<body>
    <Routes @rendermode="RenderModeForPage" />
    <script src="_framework/blazor.web.js"></script>
</body>
</html>

@code {
    [CascadingParameter]
    public HttpContext HttpContext { get; set; } = default!;

    private IComponentRenderMode? RenderModeForPage =>
        HttpContext.AcceptsInteractiveRouting()
            ? InteractiveServer   // replace with the app's render mode
            : null;
}
```

In `Routes.razor` (or wherever the router lives), use `AuthorizeRouteView`:

The rest: https://github.com/dotnet/skills/blob/HEAD/plugins/dotnet-blazor/skills/configure-auth/SKILL.md