This package contains code and extension methods to make the process of adding API key authentication to an API, including to your Swagger/Swashbuckle definition, straightforward by removing a lot of the boilerplate code.

Within the AddSwaggerGen options, add config.AddAuthorizeButton(); where config is the SwaggerGenOptions variable you have declared.

Assuming the only authentication method being used is API key, the following snippet can be used:

builder.Services.AddAuthentication(config =>
{
    config.DefaultAuthenticateScheme = ApiKeyAuthenticationOptions.DefaultScheme;
    config.DefaultChallengeScheme = ApiKeyAuthenticationOptions.DefaultScheme;
}).AddApiKeySupport();

The basic authorization policy (i.e. any key is valid for any thing), can be configured using the following snippet:

builder.Services.AddAuthorization(config =>
{
    config.AddApiPolicy(builder.Configuration);
});

By default, this looks for a config section called ApiKeys but by passing an addition parameter to AddApiPolicy, a difference configuration key can be specified.

Before mapping endpoints, add the authentication and authorization middleware:

app.UseAuthentication();
app.UseAuthorization();

Finally, add a section to appsettings.json (or another file, User Secrets, etc...) using the following format for each API key you wish to permit access:

{
  "ApiKeys": [
    "MyFirstApiKey",
    "AnotherApiKey"
  ]
}

Add the [Authorize] attribute before the controller or endpoint you wish to protect.

Method one is to add the [Authorize] attribute before the () of the handler declaration:

app.MapGet("/hellosecureworld", [Authorize] () =>
{
    return "Hello secure world!";
})

Alternativly, after the declaration, add a RequireAuthorization() call after declaring the endpoint:

app.MapGet("/hellosecureworld", () =>
{
    return "Hello secure world!";
}).RequireAuthorization();