diff --git a/src/Passwordless/Helpers/Extensions/FunctionalExtensions.cs b/src/Passwordless/Helpers/Extensions/FunctionalExtensions.cs
new file mode 100644
index 0000000..01fadaa
--- /dev/null
+++ b/src/Passwordless/Helpers/Extensions/FunctionalExtensions.cs
@@ -0,0 +1,8 @@
+using System;
+
+namespace Passwordless.Helpers.Extensions;
+
+internal static class FunctionalExtensions
+{
+    internal static TOut Pipe<TIn, TOut>(this TIn input, Func<TIn, TOut> transform) => transform(input);
+}
\ No newline at end of file
diff --git a/src/Passwordless/Helpers/PasswordlessSerializerContext.cs b/src/Passwordless/Helpers/PasswordlessSerializerContext.cs
index 57d9105..3c1b8db 100644
--- a/src/Passwordless/Helpers/PasswordlessSerializerContext.cs
+++ b/src/Passwordless/Helpers/PasswordlessSerializerContext.cs
@@ -11,7 +11,7 @@ namespace Passwordless.Helpers;
 [JsonSerializable(typeof(RegisterTokenResponse))]
 [JsonSerializable(typeof(RegisterOptions))]
 [JsonSerializable(typeof(AuthenticationTokenResponse))]
-[JsonSerializable(typeof(AuthenticationOptions))]
+[JsonSerializable(typeof(AuthenticationOptionsRequest))]
 [JsonSerializable(typeof(VerifyTokenRequest))]
 [JsonSerializable(typeof(VerifiedUser))]
 [JsonSerializable(typeof(DeleteUserRequest))]
diff --git a/src/Passwordless/IPasswordlessClient.cs b/src/Passwordless/IPasswordlessClient.cs
index 5980c33..13c555b 100644
--- a/src/Passwordless/IPasswordlessClient.cs
+++ b/src/Passwordless/IPasswordlessClient.cs
@@ -23,7 +23,7 @@ Task<RegisterTokenResponse> CreateRegisterTokenAsync(
     /// This approach can be used to implement a "magic link"-style login and other similar scenarios.
     /// </summary>
     Task<AuthenticationTokenResponse> GenerateAuthenticationTokenAsync(
-        AuthenticationOptions options,
+        AuthenticationOptions authenticationOptions,
         CancellationToken cancellationToken = default
     );
 
diff --git a/src/Passwordless/Models/AuthenticationOptions.cs b/src/Passwordless/Models/AuthenticationOptions.cs
index 6bfc9ee..98575bd 100644
--- a/src/Passwordless/Models/AuthenticationOptions.cs
+++ b/src/Passwordless/Models/AuthenticationOptions.cs
@@ -1,3 +1,12 @@
+using System;
+
 namespace Passwordless.Models;
 
-public record AuthenticationOptions(string UserId);
\ No newline at end of file
+/// <summary>
+/// Used to manually generate an authentication token.
+/// </summary>
+/// <param name="UserId">User identifier the token is intended for.</param>
+/// <param name="TimeToLive">Optional. How long a token is valid for. Default value is 15 minutes.</param>
+public record AuthenticationOptions(string UserId, TimeSpan? TimeToLive = null);
+
+internal record AuthenticationOptionsRequest(string UserId, int? TimeToLive = null);
\ No newline at end of file
diff --git a/src/Passwordless/PasswordlessClient.cs b/src/Passwordless/PasswordlessClient.cs
index bdfe4aa..7d5023e 100644
--- a/src/Passwordless/PasswordlessClient.cs
+++ b/src/Passwordless/PasswordlessClient.cs
@@ -7,6 +7,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Passwordless.Helpers;
+using Passwordless.Helpers.Extensions;
 using Passwordless.Models;
 
 namespace Passwordless;
@@ -73,12 +74,12 @@ public async Task<RegisterTokenResponse> CreateRegisterTokenAsync(
 
     /// <inheritdoc />
     public async Task<AuthenticationTokenResponse> GenerateAuthenticationTokenAsync(
-        AuthenticationOptions options,
+        AuthenticationOptions authenticationOptions,
         CancellationToken cancellationToken = default)
     {
         using var response = await _http.PostAsJsonAsync("signin/generate-token",
-            options,
-            PasswordlessSerializerContext.Default.AuthenticationOptions,
+            new AuthenticationOptionsRequest(authenticationOptions.UserId, authenticationOptions.TimeToLive?.TotalSeconds.Pipe(Convert.ToInt32)),
+            PasswordlessSerializerContext.Default.AuthenticationOptionsRequest,
             cancellationToken
         );