first commit

services/csharp/lib/SequenceAuthExtensions.cs

@@ -0,0 +1,17 @@
+using Microsoft.Extensions.DependencyInjection;
+using System;
+
+namespace SequenceAuth.Lib;
+
+public static class SequenceAuthExtensions
+{
+    public static IServiceCollection AddSequenceAuth(this IServiceCollection services, Action<SequenceAuthOptions> configureOptions)
+    {
+        ArgumentNullException.ThrowIfNull(configureOptions);
+        
+        services.Configure(configureOptions);
+        services.AddScoped<SequenceManager>();
+        
+        return services;
+    }
+}