diff --git a/src/Prospect.Server.Api/Controllers/ClientController.cs b/src/Prospect.Server.Api/Controllers/ClientController.cs
index 4d5654f..664af2d 100644
--- a/src/Prospect.Server.Api/Controllers/ClientController.cs
+++ b/src/Prospect.Server.Api/Controllers/ClientController.cs
@@ -1,4 +1,5 @@
-using Microsoft.AspNetCore.Authorization;
+using System.Net.Mime;
+using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Options;
 using Prospect.Server.Api.Config;
@@ -45,8 +46,8 @@ public class ClientController : Controller
         
     [AllowAnonymous]
     [HttpPost("LoginWithSteam")]
-    [Produces("application/json")]
-    public async Task<IActionResult> LoginWithSteam(ClientLoginWithSteamRequest request)
+    [Produces(MediaTypeNames.Application.Json)]
+    public async Task<IActionResult> LoginWithSteam(FLoginWithSteamRequest request)
     {
         if (!string.IsNullOrEmpty(request.SteamTicket))
         {
@@ -125,7 +126,7 @@ public class ClientController : Controller
     }
 
     [HttpPost("AddGenericID")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
     public IActionResult AddGenericId(FAddGenericIDRequest request)
     {
@@ -138,7 +139,7 @@ public class ClientController : Controller
     }
 
     [HttpPost("UpdateUserTitleDisplayName")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
     public IActionResult UpdateUserTitleDisplayName(FUpdateUserTitleDisplayNameRequest request)
     {
@@ -154,7 +155,7 @@ public class ClientController : Controller
     }
 
     [HttpPost("UpdateUserData")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
     public async Task<IActionResult> UpdateUserData(FUpdateUserDataRequest request)
     {
@@ -173,7 +174,7 @@ public class ClientController : Controller
     }
 
     [HttpPost("GetUserData")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
     public async Task<IActionResult> GetUserData(FGetUserDataRequest request)
     {
@@ -193,7 +194,7 @@ public class ClientController : Controller
     }
 
     [HttpPost("GetUserReadOnlyData")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
     public IActionResult GetUserReadOnlyData(FGetUserDataRequest request)
     {
@@ -210,7 +211,7 @@ public class ClientController : Controller
     }
 
     [HttpPost("GetUserInventory")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
     public IActionResult GetUserReadOnlyData(FGetUserInventoryRequest request)
     {
@@ -252,7 +253,7 @@ public class ClientController : Controller
     }
 
     [HttpPost("GetTitleData")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
     public IActionResult GetTitleData(FGetTitleDataRequest request)
     {
diff --git a/src/Prospect.Server.Api/Controllers/CloudScriptController.cs b/src/Prospect.Server.Api/Controllers/CloudScriptController.cs
index a92ce4a..6d51c86 100644
--- a/src/Prospect.Server.Api/Controllers/CloudScriptController.cs
+++ b/src/Prospect.Server.Api/Controllers/CloudScriptController.cs
@@ -1,4 +1,5 @@
-using Microsoft.AspNetCore.Authorization;
+using System.Net.Mime;
+using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Prospect.Server.Api.Models.Client;
 using Prospect.Server.Api.Models.CloudScript;
@@ -21,7 +22,7 @@ public class CloudScriptController : Controller
     }
         
     [HttpPost("ExecuteFunction")]
-    [Produces("application/json")]
+    [Produces(MediaTypeNames.Application.Json)]
     public IActionResult ExecuteFunction(FExecuteFunctionRequest request)
     {
         _logger.LogInformation("Executing function {Function}", request.FunctionName);
diff --git a/src/Prospect.Server.Api/Controllers/MultiplayerController.cs b/src/Prospect.Server.Api/Controllers/MultiplayerController.cs
new file mode 100644
index 0000000..cc5a97d
--- /dev/null
+++ b/src/Prospect.Server.Api/Controllers/MultiplayerController.cs
@@ -0,0 +1,47 @@
+using System.Net.Mime;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Prospect.Server.Api.Models.Client;
+using Prospect.Server.Api.Models.Multiplayer;
+using Prospect.Server.Api.Models.Multiplayer.Data;
+using Prospect.Server.Api.Services.Auth.Entity;
+using Prospect.Server.Api.Services.Auth.User;
+
+namespace Prospect.Server.Api.Controllers;
+
+[Route("MultiplayerServer")]
+[ApiController]
+[Authorize(AuthenticationSchemes = EntityAuthenticationOptions.DefaultScheme)]
+public class MultiplayerController : Controller
+{
+    private readonly ILogger<MultiplayerController> _logger;
+
+    public MultiplayerController(ILogger<MultiplayerController> logger)
+    {
+        _logger = logger;
+    }
+
+    [HttpPost("ListQosServersForTitle")]
+    [Produces(MediaTypeNames.Application.Json)]
+    [Authorize(AuthenticationSchemes = UserAuthenticationOptions.DefaultScheme)]
+    public IActionResult ListQosServersForTitle(FListQosServersForTitleRequest request)
+    {
+        return Ok(new ClientResponse<object>
+        {
+            Code = 200,
+            Status = "OK",
+            Data = new FListQosServersForTitleResponse
+            {
+                PageSize = 1,
+                QosServers = new List<FQosServer>
+                {
+                    new FQosServer
+                    {
+                        Region = "NorthEurope",
+                        ServerUrl = "127.0.0.1"
+                    }
+                }
+            }
+        });
+    }
+}
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/ClientLoginWithSteamRequest.cs b/src/Prospect.Server.Api/Models/Client/ClientLoginWithSteamRequest.cs
deleted file mode 100644
index cc9424b..0000000
--- a/src/Prospect.Server.Api/Models/Client/ClientLoginWithSteamRequest.cs
+++ /dev/null
@@ -1,58 +0,0 @@
-using System.Text.Json;
-using System.Text.Json.Serialization;
-
-namespace Prospect.Server.Api.Models.Client;
-
-public class ClientLoginWithSteamRequest
-{
-    [JsonPropertyName("CreateAccount")]
-    public bool CreateAccount { get; set; }
-        
-    [JsonPropertyName("CustomTags")]
-    public JsonDocument CustomTags { get; set; }
-        
-    [JsonPropertyName("EncryptedRequest")]
-    public string EncryptedRequest { get; set; }
-        
-    [JsonPropertyName("InfoRequestParameters")]
-    public InfoParameters InfoRequestParameters { get; set; }
-        
-    [JsonPropertyName("PlayerSecret")]
-    public string PlayerSecret { get; set; }
-        
-    [JsonPropertyName("SteamTicket")]
-    public string SteamTicket { get; set; }
-}
-
-public class InfoParameters
-{
-    [JsonPropertyName("GetCharacterInventories")]
-    public bool GetCharacterInventories { get; set; }
-
-    [JsonPropertyName("GetCharacterList")]
-    public bool GetCharacterList { get; set; }
-
-    [JsonPropertyName("GetPlayerProfile")]
-    public bool GetPlayerProfile { get; set; }
-
-    [JsonPropertyName("GetPlayerStatistics")]
-    public bool GetPlayerStatistics { get; set; }
-
-    [JsonPropertyName("GetTitleData")]
-    public bool GetTitleData { get; set; }
-
-    [JsonPropertyName("GetUserAccountInfo")]
-    public bool GetUserAccountInfo { get; set; }
-
-    [JsonPropertyName("GetUserData")]
-    public bool GetUserData { get; set; }
-
-    [JsonPropertyName("GetUserInventory")]
-    public bool GetUserInventory { get; set; }
-
-    [JsonPropertyName("GetUserReadOnlyData")]
-    public bool GetUserReadOnlyData { get; set; }
-
-    [JsonPropertyName("GetUserVirtualCurrency")]
-    public bool GetUserVirtualCurrency { get; set; }
-}
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FEntityKey.cs b/src/Prospect.Server.Api/Models/Client/Data/FEntityKey.cs
index 132149d..9c59ce9 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FEntityKey.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FEntityKey.cs
@@ -8,15 +8,15 @@ public class FEntityKey
     ///     Unique ID of the entity.
     /// </summary>
     [JsonPropertyName("Id")]
-    public string Id { get; set; }
+    public string Id { get; set; } = null!;
 
     /// <summary>
     ///     [optional] Entity type. See https://docs.microsoft.com/gaming/playfab/features/data/entities/available-built-in-entity-types
     /// </summary>
     [JsonPropertyName("Type")]
-    public string Type { get; set; }
+    public string? Type { get; set; }
 
     // Not in PlayFab SDK
-    [JsonPropertyName("TypeString")]
-    public string TypeString { get; set; }
+    [JsonPropertyName("TypeString")] 
+    public string TypeString { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FEntityTokenResponse.cs b/src/Prospect.Server.Api/Models/Client/Data/FEntityTokenResponse.cs
index 65ee1b7..36fc135 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FEntityTokenResponse.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FEntityTokenResponse.cs
@@ -9,14 +9,14 @@ public class FEntityTokenResponse
     /// </summary>
     [JsonPropertyName("Entity")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FEntityKey Entity { get; set; }
+    public FEntityKey? Entity { get; set; }
         
     /// <summary>
     ///     [optional] The token used to set X-EntityToken for all entity based API calls.
     /// </summary>
     [JsonPropertyName("EntityToken")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string EntityToken { get; set; }
+    public string? EntityToken { get; set; }
 
     /// <summary>
     ///     [optional] The time the token will expire, if it is an expiring token, in UTC.
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FFunctionExecutionError.cs b/src/Prospect.Server.Api/Models/Client/Data/FFunctionExecutionError.cs
index 0e4aed7..30ce3cd 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FFunctionExecutionError.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FFunctionExecutionError.cs
@@ -10,19 +10,19 @@ public class FFunctionExecutionError
     /// </summary>
     [JsonPropertyName("Error")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Error { get; set; }
+    public string? Error { get; set; }
         
     /// <summary>
     ///     [optional] Details about the error
     /// </summary>
     [JsonPropertyName("Message")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Message { get; set; }
+    public string? Message { get; set; }
         
     /// <summary>
     ///     [optional] Point during the execution of the function at which the error occurred, if any
     /// </summary>
     [JsonPropertyName("StackTrace")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string StackTrace { get; set; }
+    public string? StackTrace { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FGenericServiceId.cs b/src/Prospect.Server.Api/Models/Client/Data/FGenericServiceId.cs
index 994672e..bd61808 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FGenericServiceId.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FGenericServiceId.cs
@@ -8,11 +8,11 @@ public class FGenericServiceId
     ///     Name of the service for which the player has a unique identifier.
     /// </summary>
     [JsonPropertyName("ServiceName")]
-    public string ServiceName { get; set; }
+    public string ServiceName { get; set; } = null!;
         
     /// <summary>
     ///     Unique identifier of the player in that service.
     /// </summary>
     [JsonPropertyName("UserId")]
-    public string UserId { get; set; }
+    public string UserId { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FGetPlayerCombinedInfoRequestParams.cs b/src/Prospect.Server.Api/Models/Client/Data/FGetPlayerCombinedInfoRequestParams.cs
new file mode 100644
index 0000000..fefc685
--- /dev/null
+++ b/src/Prospect.Server.Api/Models/Client/Data/FGetPlayerCombinedInfoRequestParams.cs
@@ -0,0 +1,66 @@
+using System.Text.Json.Serialization;
+
+namespace Prospect.Server.Api.Models.Client.Data;
+
+public class FGetPlayerCombinedInfoRequestParams
+{
+    /// <summary>
+    ///     Whether to get character inventories. Defaults to false.
+    /// </summary>
+    [JsonPropertyName("GetCharacterInventories")]
+    public bool GetCharacterInventories { get; set; }
+
+    /// <summary>
+    ///     Whether to get the list of characters. Defaults to false.
+    /// </summary>
+    [JsonPropertyName("GetCharacterList")]
+    public bool GetCharacterList { get; set; }
+
+    /// <summary>
+    ///     Whether to get player profile. Defaults to false. Has no effect for a new player.
+    /// </summary>
+    [JsonPropertyName("GetPlayerProfile")]
+    public bool GetPlayerProfile { get; set; }
+
+    /// <summary>
+    ///     Whether to get player statistics. Defaults to false.
+    /// </summary>
+    [JsonPropertyName("GetPlayerStatistics")]
+    public bool GetPlayerStatistics { get; set; }
+
+    /// <summary>
+    ///     Whether to get title data. Defaults to false.
+    /// </summary>
+    [JsonPropertyName("GetTitleData")]
+    public bool GetTitleData { get; set; }
+
+    /// <summary>
+    ///     Whether to get the player's account Info. Defaults to false
+    /// </summary>
+    [JsonPropertyName("GetUserAccountInfo")]
+    public bool GetUserAccountInfo { get; set; }
+
+    /// <summary>
+    ///     Whether to get the player's custom data. Defaults to false
+    /// </summary>
+    [JsonPropertyName("GetUserData")]
+    public bool GetUserData { get; set; }
+
+    /// <summary>
+    ///     Whether to get the player's inventory. Defaults to false
+    /// </summary>
+    [JsonPropertyName("GetUserInventory")]
+    public bool GetUserInventory { get; set; }
+
+    /// <summary>
+    ///     Whether to get the player's read only data. Defaults to false
+    /// </summary>
+    [JsonPropertyName("GetUserReadOnlyData")]
+    public bool GetUserReadOnlyData { get; set; }
+
+    /// <summary>
+    ///     Whether to get the player's virtual currency balances. Defaults to false
+    /// </summary>
+    [JsonPropertyName("GetUserVirtualCurrency")]
+    public bool GetUserVirtualCurrency { get; set; }
+}
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FGetPlayerCombinedInfoResultPayload.cs b/src/Prospect.Server.Api/Models/Client/Data/FGetPlayerCombinedInfoResultPayload.cs
index e7e8b39..9333abc 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FGetPlayerCombinedInfoResultPayload.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FGetPlayerCombinedInfoResultPayload.cs
@@ -11,7 +11,7 @@ public class FGetPlayerCombinedInfoResultPayload
     /// </summary>
     [JsonPropertyName("CharacterInventories")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public List<object> CharacterInventories { get; set; }
+    public List<object>? CharacterInventories { get; set; }
         
     // TArray<FCharacterResult> CharacterList;
 
@@ -21,7 +21,7 @@ public class FGetPlayerCombinedInfoResultPayload
     /// </summary>
     [JsonPropertyName("PlayerProfile")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FPlayerProfileModel PlayerProfile { get; set; }
+    public FPlayerProfileModel? PlayerProfile { get; set; }
         
     // TArray<FStatisticValue> PlayerStatistics;
         
@@ -41,7 +41,7 @@ public class FGetPlayerCombinedInfoResultPayload
     /// </summary>
     [JsonPropertyName("UserInventory")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public List<object> UserInventory { get; set; }
+    public List<object>? UserInventory { get; set; }
 
     // TMap<FString, FUserDataRecord> UserReadOnlyData;
         
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FItemInstance.cs b/src/Prospect.Server.Api/Models/Client/Data/FItemInstance.cs
index bb8371b..5b48e70 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FItemInstance.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FItemInstance.cs
@@ -9,14 +9,14 @@ public class FItemInstance
     /// </summary>
     [JsonPropertyName("Annotation")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Annotation { get; set; }
+    public string? Annotation { get; set; }
         
     /// <summary>
     ///     [optional] Array of unique items that were awarded when this catalog item was purchased.
     /// </summary>
     [JsonPropertyName("BundleContents")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public List<string> BundleContents { get; set; }
+    public List<string>? BundleContents { get; set; }
         
     /// <summary>
     ///     [optional] Unique identifier for the parent inventory item, as defined in the catalog, for object which were added from a bundle or
@@ -24,14 +24,14 @@ public class FItemInstance
     /// </summary>
     [JsonPropertyName("BundleParent")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string BundleParent { get; set; }
+    public string? BundleParent { get; set; }
         
     /// <summary>
     ///     [optional] Catalog version for the inventory item, when this instance was created.
     /// </summary>
     [JsonPropertyName("CatalogVersion")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string CatalogVersion { get; set; }
+    public string? CatalogVersion { get; set; }
         
     /// <summary>
     ///     [optional] A set of custom key-value pairs on the instance of the inventory item, which is not to be confused with the catalog
@@ -39,14 +39,14 @@ public class FItemInstance
     /// </summary>
     [JsonPropertyName("CustomData")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, string> CustomData { get; set; }
+    public Dictionary<string, string>? CustomData { get; set; }
         
     /// <summary>
     ///     [optional] CatalogItem.DisplayName at the time this item was purchased.
     /// </summary>
     [JsonPropertyName("DisplayName")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string DisplayName { get; set; }
+    public string? DisplayName { get; set; }
         
     /// <summary>
     ///     [optional] Timestamp for when this instance will expire.
@@ -60,21 +60,21 @@ public class FItemInstance
     /// </summary>
     [JsonPropertyName("ItemClass")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string ItemClass { get; set; }
+    public string? ItemClass { get; set; }
         
     /// <summary>
     ///     [optional] Unique identifier for the inventory item, as defined in the catalog.
     /// </summary>
     [JsonPropertyName("ItemId")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string ItemId { get; set; }
+    public string? ItemId { get; set; }
         
     /// <summary>
     ///     [optional] Unique item identifier for this specific instance of the item.
     /// </summary>
     [JsonPropertyName("ItemInstanceId")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string ItemInstanceId { get; set; }
+    public string? ItemInstanceId { get; set; }
         
     /// <summary>
     ///     [optional] Timestamp for when this instance was purchased.
@@ -95,7 +95,7 @@ public class FItemInstance
     /// </summary>
     [JsonPropertyName("UnitCurrency")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string UnitCurrency { get; set; }
+    public string? UnitCurrency { get; set; }
         
     /// <summary>
     ///     Cost of the catalog item in the given currency. Not available when granting items.
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FLogStatement.cs b/src/Prospect.Server.Api/Models/Client/Data/FLogStatement.cs
index ef4306b..fd918c0 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FLogStatement.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FLogStatement.cs
@@ -9,19 +9,19 @@ public class FLogStatement
     /// </summary>
     [JsonPropertyName("Data")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public object Data { get; set; }
+    public object? Data { get; set; }
         
     /// <summary>
     ///     [optional] 'Debug', 'Info', or 'Error'
     /// </summary>
     [JsonPropertyName("Level")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Level { get; set; }
+    public string? Level { get; set; }
         
     /// <summary>
     ///     [optional] undefined
     /// </summary>
     [JsonPropertyName("Message")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Message { get; set; }
+    public string? Message { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FPlayerProfileModel.cs b/src/Prospect.Server.Api/Models/Client/Data/FPlayerProfileModel.cs
index fa835c6..f7911e8 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FPlayerProfileModel.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FPlayerProfileModel.cs
@@ -9,26 +9,26 @@ public class FPlayerProfileModel
     /// </summary>
     [JsonPropertyName("DisplayName")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string DisplayName { get; set; }
+    public string? DisplayName { get; set; }
         
     /// <summary>
     ///     [optional] PlayFab player account unique identifier
     /// </summary>
     [JsonPropertyName("PlayerId")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string PlayerId { get; set; }
+    public string? PlayerId { get; set; }
         
     /// <summary>
     ///     [optional] Publisher this player belongs to
     /// </summary>
     [JsonPropertyName("PublisherId")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string PublisherId { get; set; }
+    public string? PublisherId { get; set; }
 
     /// <summary>
     ///     [optional] Title ID this player profile applies to
     /// </summary>
     [JsonPropertyName("TitleId")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string TitleId { get; set; }
+    public string? TitleId { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FScriptExecutionError.cs b/src/Prospect.Server.Api/Models/Client/Data/FScriptExecutionError.cs
index 22afdfc..5016b02 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FScriptExecutionError.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FScriptExecutionError.cs
@@ -10,19 +10,19 @@ public class FScriptExecutionError
     /// </summary>
     [JsonPropertyName("Error")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Error { get; set; }
+    public string? Error { get; set; }
         
     /// <summary>
     ///     [optional] Details about the error
     /// </summary>
     [JsonPropertyName("Message")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Message { get; set; }
+    public string? Message { get; set; }
         
     /// <summary>
     ///     [optional] Point during the execution of the script at which the error occurred, if any
     /// </summary>
     [JsonPropertyName("StackTrace")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string StackTrace { get; set; }
+    public string? StackTrace { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FTreatmentAssignment.cs b/src/Prospect.Server.Api/Models/Client/Data/FTreatmentAssignment.cs
index 3823e5e..8690a6f 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FTreatmentAssignment.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FTreatmentAssignment.cs
@@ -9,12 +9,12 @@ public class FTreatmentAssignment
     /// </summary>
     [JsonPropertyName("Variables")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public List<FVariable> Variables { get; set; }
+    public List<FVariable>? Variables { get; set; }
         
     /// <summary>
     ///     [optional] List of the experiment variants.
     /// </summary>
     [JsonPropertyName("Variants")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public List<string> Variants { get; set; }
+    public List<string>? Variants { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FUserDataRecord.cs b/src/Prospect.Server.Api/Models/Client/Data/FUserDataRecord.cs
index 3ea8225..7f6487f 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FUserDataRecord.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FUserDataRecord.cs
@@ -16,12 +16,12 @@ public class FUserDataRecord
     /// </summary>
     [JsonPropertyName("Permission")]
     [JsonConverter(typeof(JsonStringEnumConverter))]
-    public UserDataPermission Permission { get; set; }
+    public UserDataPermission? Permission { get; set; }
         
     /// <summary>
     ///     [optional] Data stored for the specified user data key.
     /// </summary>
     [JsonPropertyName("Value")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Value { get; set; }
+    public string? Value { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/Data/FVariable.cs b/src/Prospect.Server.Api/Models/Client/Data/FVariable.cs
index abbb384..7c790fe 100644
--- a/src/Prospect.Server.Api/Models/Client/Data/FVariable.cs
+++ b/src/Prospect.Server.Api/Models/Client/Data/FVariable.cs
@@ -8,12 +8,12 @@ public class FVariable
     ///     Name of the variable.
     /// </summary>
     [JsonPropertyName("Name")]
-    public string Name { get; set; }
+    public string Name { get; set; } = null!;
         
     /// <summary>
     ///     [optional] Value of the variable.
     /// </summary>
     [JsonPropertyName("Value")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string Value { get; set; }
+    public string? Value { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FAddGenericIDRequest.cs b/src/Prospect.Server.Api/Models/Client/FAddGenericIDRequest.cs
index e3046ff..5df4465 100644
--- a/src/Prospect.Server.Api/Models/Client/FAddGenericIDRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FAddGenericIDRequest.cs
@@ -5,6 +5,9 @@ namespace Prospect.Server.Api.Models.Client;
 
 public class FAddGenericIDRequest
 {
+    /// <summary>
+    ///     Generic service identifier to add to the player account.
+    /// </summary>
     [JsonPropertyName("GenericId")]
-    public FGenericServiceId GenericId { get; set; }
+    public FGenericServiceId GenericId { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptResult.cs b/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptResult.cs
index c0b7fd0..385a62a 100644
--- a/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptResult.cs
+++ b/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptResult.cs
@@ -16,7 +16,7 @@ public class FExecuteCloudScriptResult
     /// </summary>
     [JsonPropertyName("Error")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FScriptExecutionError Error { get; set; }
+    public FScriptExecutionError? Error { get; set; }
         
     [JsonPropertyName("ExecutionTimeSeconds")]
     public double? ExecutionTimeSeconds { get; set; }
@@ -26,14 +26,14 @@ public class FExecuteCloudScriptResult
     /// </summary>
     [JsonPropertyName("FunctionName")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string FunctionName { get; set; }
+    public string? FunctionName { get; set; }
         
     /// <summary>
     ///     [optional] The object returned from the CloudScript function, if any
     /// </summary>
     [JsonPropertyName("FunctionResult")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public object FunctionResult { get; set; }
+    public object? FunctionResult { get; set; }
         
     /// <summary>
     ///     [optional] Flag indicating if the FunctionResult was too large and was subsequently dropped from this event. This only occurs if
@@ -55,7 +55,7 @@ public class FExecuteCloudScriptResult
     /// </summary>
     [JsonPropertyName("Logs")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public List<FLogStatement> Logs { get; set; }
+    public List<FLogStatement>? Logs { get; set; }
         
     /// <summary>
     ///     [optional] Flag indicating if the logs were too large and were subsequently dropped from this event. This only occurs if the total
diff --git a/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptServerRequest.cs b/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptServerRequest.cs
index eab768c..8124186 100644
--- a/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptServerRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FExecuteCloudScriptServerRequest.cs
@@ -10,20 +10,20 @@ public class FExecuteCloudScriptServerRequest
     /// </summary>
     [JsonPropertyName("CustomTags")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, string> CustomTags { get; set; }
+    public Dictionary<string, string>? CustomTags { get; set; }
 
     /// <summary>
     ///     The name of the CloudScript function to execute
     /// </summary>
     [JsonPropertyName("FunctionName")]
-    public string FunctionName { get; set; }
+    public string FunctionName { get; set; } = null!;
 
     /// <summary>
     ///     [optional] Object that is passed in to the function as the first argument
     /// </summary>
     [JsonPropertyName("FunctionParameter")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string FunctionParameter { get; set; }
+    public string? FunctionParameter { get; set; }
 
     /// <summary>
     ///     [optional] Generate a 'player_executed_cloudscript' PlayStream event containing the results of the function execution and other
@@ -32,12 +32,12 @@ public class FExecuteCloudScriptServerRequest
     [JsonPropertyName("GeneratePlayStreamEvent")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
     public bool? GeneratePlayStreamEvent { get; set; }
-        
+
     /// <summary>
     ///     The unique user identifier for the player on whose behalf the script is being run
     /// </summary>
     [JsonPropertyName("PlayFabId")]
-    public string PlayFabId { get; set; }
+    public string PlayFabId { get; set; } = null!;
         
     /// <summary>
     ///     [optional] Option for which revision of the CloudScript to execute. 'Latest' executes the most recently created revision, 'Live'
diff --git a/src/Prospect.Server.Api/Models/Client/FExecuteFunctionRequest.cs b/src/Prospect.Server.Api/Models/Client/FExecuteFunctionRequest.cs
index 35117b6..cb762d7 100644
--- a/src/Prospect.Server.Api/Models/Client/FExecuteFunctionRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FExecuteFunctionRequest.cs
@@ -10,27 +10,27 @@ public class FExecuteFunctionRequest
     /// </summary>
     [JsonPropertyName("CustomTags")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, string> CustomTags { get; set; }
+    public Dictionary<string, string>? CustomTags { get; set; }
         
     /// <summary>
     ///     [optional] The entity to perform this action on.
     /// </summary>
     [JsonPropertyName("Entity")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FEntityKey Entity { get; set; }
+    public FEntityKey? Entity { get; set; }
         
     /// <summary>
     ///     The name of the CloudScript function to execute
     /// </summary>
     [JsonPropertyName("FunctionName")]
-    public string FunctionName { get; set; }
+    public string? FunctionName { get; set; }
         
     /// <summary>
     ///     [optional] Object that is passed in to the function as the FunctionArgument field of the FunctionExecutionContext data structure
     /// </summary>
     [JsonPropertyName("FunctionParameter")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string FunctionParameter { get; set; }
+    public string? FunctionParameter { get; set; }
         
     /// <summary>
     ///     [optional] Generate a 'entity_executed_cloudscript_function' PlayStream event containing the results of the function execution and
diff --git a/src/Prospect.Server.Api/Models/Client/FExecuteFunctionResult.cs b/src/Prospect.Server.Api/Models/Client/FExecuteFunctionResult.cs
index 24255a0..c967174 100644
--- a/src/Prospect.Server.Api/Models/Client/FExecuteFunctionResult.cs
+++ b/src/Prospect.Server.Api/Models/Client/FExecuteFunctionResult.cs
@@ -10,8 +10,8 @@ public class FExecuteFunctionResult
     /// </summary>
     [JsonPropertyName("Error")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FFunctionExecutionError Error { get; set; }
-        
+    public FFunctionExecutionError? Error { get; set; }
+
     /// <summary>
     ///     The amount of time the function took to execute
     /// </summary>
@@ -22,14 +22,14 @@ public class FExecuteFunctionResult
     ///     [optional] The name of the function that executed
     /// </summary>
     [JsonPropertyName("FunctionName")]
-    public string FunctionName { get; set; }
+    public string? FunctionName { get; set; }
         
     /// <summary>
     ///     [optional] The object returned from the function, if any
     /// </summary>
     [JsonPropertyName("FunctionResult")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public object FunctionResult { get; set; }
+    public object? FunctionResult { get; set; }
         
     /// <summary>
     ///     [optional] Flag indicating if the FunctionResult was too large and was subsequently dropped from this event.
diff --git a/src/Prospect.Server.Api/Models/Client/FGetTitleDataRequest.cs b/src/Prospect.Server.Api/Models/Client/FGetTitleDataRequest.cs
index 8215c45..1325704 100644
--- a/src/Prospect.Server.Api/Models/Client/FGetTitleDataRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FGetTitleDataRequest.cs
@@ -8,12 +8,12 @@ public class FGetTitleDataRequest
     ///     [optional] Specific keys to search for in the title data (leave null to get all keys)
     /// </summary>
     [JsonPropertyName("Keys")]
-    public List<string> Keys { get; set; }
+    public List<string>? Keys { get; set; }
         
     /// <summary>
     ///     [optional] Name of the override. This value is ignored when used by the game client; otherwise, the overrides are applied
     ///     automatically to the title data.
     /// </summary>
     [JsonPropertyName("OverrideLabel")]
-    public string OverrideLabel { get; set; }
+    public string? OverrideLabel { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FGetTitleDataResult.cs b/src/Prospect.Server.Api/Models/Client/FGetTitleDataResult.cs
index 5d90ae9..8dc8e6a 100644
--- a/src/Prospect.Server.Api/Models/Client/FGetTitleDataResult.cs
+++ b/src/Prospect.Server.Api/Models/Client/FGetTitleDataResult.cs
@@ -8,5 +8,5 @@ public class FGetTitleDataResult
     ///     [optional] a dictionary object of key / value pairs
     /// </summary>
     [JsonPropertyName("Data")]
-    public Dictionary<string, string> Data { get; set; }
+    public Dictionary<string, string>? Data { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FGetUserDataRequest.cs b/src/Prospect.Server.Api/Models/Client/FGetUserDataRequest.cs
index 235374b..8d9ebf2 100644
--- a/src/Prospect.Server.Api/Models/Client/FGetUserDataRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FGetUserDataRequest.cs
@@ -9,18 +9,18 @@ public class FGetUserDataRequest
     ///     version in the system is greater than this.
     /// </summary>
     [JsonPropertyName("IfChangedFromDataVersion")]
-    public List<uint> IfChangedFromDataVersion { get; set; }
+    public List<uint>? IfChangedFromDataVersion { get; set; }
         
     /// <summary>
     ///     [optional] List of unique keys to load from.
     /// </summary>
     [JsonPropertyName("Keys")]
-    public List<string> Keys { get; set; }
+    public List<string>? Keys { get; set; }
         
     /// <summary>
     ///     [optional] Unique PlayFab identifier of the user to load data for. Optional, defaults to yourself if not set. When specified to a
     ///     PlayFab id of another player, then this will only return public keys for that account.
     /// </summary>
     [JsonPropertyName("PlayFabId")]
-    public string PlayFabId { get; set; }
+    public string? PlayFabId { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FGetUserDataResult.cs b/src/Prospect.Server.Api/Models/Client/FGetUserDataResult.cs
index e1d54ab..8a33ad0 100644
--- a/src/Prospect.Server.Api/Models/Client/FGetUserDataResult.cs
+++ b/src/Prospect.Server.Api/Models/Client/FGetUserDataResult.cs
@@ -9,12 +9,12 @@ public class FGetUserDataResult
     ///     [optional] User specific data for this title.
     /// </summary>
     [JsonPropertyName("Data")]
-    public Dictionary<string, FUserDataRecord> Data { get; set; }
+    public Dictionary<string, FUserDataRecord>? Data { get; set; }
         
     /// <summary>
     ///     [optional] Indicates the current version of the data that has been set. This is incremented with every set call for that type of
     ///     data (read-only, internal, etc). This version can be provided in Get calls to find updated data.
     /// </summary>
     [JsonPropertyName("DataVersion")]
-    public uint DataVersion { get; set; }
+    public uint? DataVersion { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FGetUserInventoryRequest.cs b/src/Prospect.Server.Api/Models/Client/FGetUserInventoryRequest.cs
index 95958cc..8a5a203 100644
--- a/src/Prospect.Server.Api/Models/Client/FGetUserInventoryRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FGetUserInventoryRequest.cs
@@ -9,5 +9,5 @@ public class FGetUserInventoryRequest
     /// </summary>
     [JsonPropertyName("CustomTags")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, string> CustomTags { get; set; }
+    public Dictionary<string, string>? CustomTags { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FGetUserInventoryResult.cs b/src/Prospect.Server.Api/Models/Client/FGetUserInventoryResult.cs
index 618a56f..bff46e6 100644
--- a/src/Prospect.Server.Api/Models/Client/FGetUserInventoryResult.cs
+++ b/src/Prospect.Server.Api/Models/Client/FGetUserInventoryResult.cs
@@ -10,19 +10,19 @@ public class FGetUserInventoryResult
     /// </summary>
     [JsonPropertyName("Inventory")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public List<FItemInstance> Inventory { get; set; }
+    public List<FItemInstance>? Inventory { get; set; }
         
     /// <summary>
     ///     [optional] Array of virtual currency balance(s) belonging to the user.
     /// </summary>
     [JsonPropertyName("VirtualCurrency")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, int> VirtualCurrency { get; set; }
+    public Dictionary<string, int>? VirtualCurrency { get; set; }
         
     /// <summary>
     ///     [optional] Array of virtual currency balance(s) belonging to the user.
     /// </summary>
     [JsonPropertyName("VirtualCurrencyRechargeTimes")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, FVirtualCurrencyRechargeTime> VirtualCurrencyRechargeTimes { get; set; }
+    public Dictionary<string, FVirtualCurrencyRechargeTime>? VirtualCurrencyRechargeTimes { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FLoginWithSteamRequest.cs b/src/Prospect.Server.Api/Models/Client/FLoginWithSteamRequest.cs
new file mode 100644
index 0000000..dd8906c
--- /dev/null
+++ b/src/Prospect.Server.Api/Models/Client/FLoginWithSteamRequest.cs
@@ -0,0 +1,50 @@
+using System.Text.Json.Serialization;
+using Prospect.Server.Api.Models.Client.Data;
+
+namespace Prospect.Server.Api.Models.Client;
+
+public class FLoginWithSteamRequest
+{
+    /// <summary>
+    ///     [optional] Automatically create a PlayFab account if one is not currently linked to this ID.
+    /// </summary>
+    [JsonPropertyName("CreateAccount")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public bool? CreateAccount { get; set; }
+        
+    /// <summary>
+    ///     [optional] The optional custom tags associated with the request (e.g. build number, external trace identifiers, etc.).
+    /// </summary>
+    [JsonPropertyName("CustomTags")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public Dictionary<string, string>? CustomTags { get; set; }
+        
+    /// <summary>
+    ///     [optional] Base64 encoded body that is encrypted with the Title's public RSA key (Enterprise Only).
+    /// </summary>
+    [JsonPropertyName("EncryptedRequest")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public string? EncryptedRequest { get; set; }
+        
+    /// <summary>
+    ///     [optional] Flags for which pieces of info to return for the user.
+    /// </summary>
+    [JsonPropertyName("InfoRequestParameters")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public FGetPlayerCombinedInfoRequestParams? InfoRequestParameters { get; set; }
+        
+    /// <summary>
+    ///     [optional] Player secret that is used to verify API request signatures (Enterprise Only).
+    /// </summary>
+    [JsonPropertyName("PlayerSecret")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public string? PlayerSecret { get; set; }
+        
+    /// <summary>
+    ///     [optional] Authentication token for the user, returned as a byte array from Steam, and converted to a string (for example, the byte
+    ///     0x08 should become "08").
+    /// </summary>
+    [JsonPropertyName("SteamTicket")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public string? SteamTicket { get; set; }
+}
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FServerLoginResult.cs b/src/Prospect.Server.Api/Models/Client/FServerLoginResult.cs
index 0cdb9f3..a1c4a52 100644
--- a/src/Prospect.Server.Api/Models/Client/FServerLoginResult.cs
+++ b/src/Prospect.Server.Api/Models/Client/FServerLoginResult.cs
@@ -11,13 +11,13 @@ public class FServerLoginResult
     /// </summary>
     [JsonPropertyName("EntityToken")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FEntityTokenResponse EntityToken { get; set; }
+    public FEntityTokenResponse? EntityToken { get; set; }
         
     /// <summary>
     ///     [optional] Results for requested info.
     /// </summary>
     [JsonPropertyName("InfoResultPayload")]
-    public FGetPlayerCombinedInfoResultPayload InfoResultPayload { get; set; }
+    public FGetPlayerCombinedInfoResultPayload? InfoResultPayload { get; set; }
         
     /// <summary>
     ///     [optional] The time of this user's previous login. If there was no previous login, then it's DateTime.MinValue
@@ -37,26 +37,26 @@ public class FServerLoginResult
     /// </summary>
     [JsonPropertyName("PlayFabId")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string PlayFabId { get; set; }
+    public string? PlayFabId { get; set; }
         
     /// <summary>
     ///     [optional] Unique token authorizing the user and game at the server level, for the current session.
     /// </summary>
     [JsonPropertyName("SessionTicket")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public string SessionTicket { get; set; }
+    public string? SessionTicket { get; set; }
         
     /// <summary>
     ///     [optional] Settings specific to this user.
     /// </summary>
     [JsonPropertyName("SettingsForUser")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FUserSettings SettingsForUser { get; set; }
+    public FUserSettings? SettingsForUser { get; set; }
 
     /// <summary>
     ///     [optional] The experimentation treatments for this user at the time of login.
     /// </summary>
     [JsonPropertyName("TreatmentAssignment")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public FTreatmentAssignment TreatmentAssignment { get; set; }
+    public FTreatmentAssignment? TreatmentAssignment { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FUpdateUserDataRequest.cs b/src/Prospect.Server.Api/Models/Client/FUpdateUserDataRequest.cs
index f2b953f..5a4ee65 100644
--- a/src/Prospect.Server.Api/Models/Client/FUpdateUserDataRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FUpdateUserDataRequest.cs
@@ -10,19 +10,19 @@ public class FUpdateUserDataRequest
     /// </summary>
     [JsonPropertyName("CustomTags")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, string> CustomTags { get; set; }
+    public Dictionary<string, string>? CustomTags { get; set; }
         
     /// <summary>
     ///     [optional] Key-value pairs to be written to the custom data. Note that keys are trimmed of whitespace, are limited in size, and may
     ///     not begin with a '!' character or be null.
     /// </summary>
-    public Dictionary<string, string> Data { get; set; }
+    public Dictionary<string, string>? Data { get; set; }
         
     /// <summary>
     ///     [optional] Optional list of Data-keys to remove from UserData. Some SDKs cannot insert null-values into Data due to language
     ///     constraints. Use this to delete the keys directly.
     /// </summary>
-    public List<string> KeysToRemove { get; set; }
+    public List<string>? KeysToRemove { get; set; }
         
     /// <summary>
     ///     [optional] Permission to be applied to all user data keys written in this request. Defaults to "private" if not set.
diff --git a/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameRequest.cs b/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameRequest.cs
index bb0072b..19a6e05 100644
--- a/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameRequest.cs
+++ b/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameRequest.cs
@@ -9,11 +9,11 @@ public class FUpdateUserTitleDisplayNameRequest
     /// </summary>
     [JsonPropertyName("CustomTags")]
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
-    public Dictionary<string, string> CustomTags { get; set; }
-        
+    public Dictionary<string, string>? CustomTags { get; set; }
+
     /// <summary>
     ///     New title display name for the user - must be between 3 and 25 characters.
     /// </summary>
     [JsonPropertyName("DisplayName")]
-    public string DisplayName { get; set; }
+    public string DisplayName { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameResult.cs b/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameResult.cs
index 32d87c8..1e6e738 100644
--- a/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameResult.cs
+++ b/src/Prospect.Server.Api/Models/Client/FUpdateUserTitleDisplayNameResult.cs
@@ -5,5 +5,5 @@ public class FUpdateUserTitleDisplayNameResult
     /// <summary>
     ///     [optional] Current title display name for the user (this will be the original display name if the rename attempt failed).
     /// </summary>
-    public string DisplayName { get; set; }
+    public string? DisplayName { get; set; }
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/CloudScript/Data/FYActiveContractPlayerData.cs b/src/Prospect.Server.Api/Models/CloudScript/Data/FYActiveContractPlayerData.cs
index e66f73a..02d4a0b 100644
--- a/src/Prospect.Server.Api/Models/CloudScript/Data/FYActiveContractPlayerData.cs
+++ b/src/Prospect.Server.Api/Models/CloudScript/Data/FYActiveContractPlayerData.cs
@@ -4,9 +4,9 @@ namespace Prospect.Server.Api.Models.CloudScript.Data;
 
 public class FYActiveContractPlayerData
 {
-    [JsonPropertyName("contractId")]
-    public string ContractId { get; set; }
+    [JsonPropertyName("contractId")] 
+    public string ContractId { get; set; } = null!;
 
     [JsonPropertyName("progress")]
-    public List<int> Progress { get; set; }
+    public List<int> Progress { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractData.cs b/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractData.cs
index 5e672f8..ca84442 100644
--- a/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractData.cs
+++ b/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractData.cs
@@ -5,7 +5,7 @@ namespace Prospect.Server.Api.Models.CloudScript.Data;
 public class FYFactionContractData
 {
     [JsonPropertyName("contractId")]
-    public string ContractId { get; set; }
+    public string ContractId { get; set; } = null!;
 
     [JsonPropertyName("contractIsLockedDueToLowFactionReputation")]
     public bool ContractIsLockedDueToLowFactionReputation { get; set; }
diff --git a/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractsData.cs b/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractsData.cs
index d04572a..4a15432 100644
--- a/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractsData.cs
+++ b/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionContractsData.cs
@@ -5,8 +5,8 @@ namespace Prospect.Server.Api.Models.CloudScript.Data;
 public class FYFactionContractsData
 {
     [JsonPropertyName("factionId")]
-    public string FactionId { get; set; }
+    public string FactionId { get; set; } = null!;
 
     [JsonPropertyName("contracts")]
-    public List<FYFactionContractData> Contracts { get; set; }
+    public List<FYFactionContractData> Contracts { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionsContractsData.cs b/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionsContractsData.cs
index c9e8b10..2cbddca 100644
--- a/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionsContractsData.cs
+++ b/src/Prospect.Server.Api/Models/CloudScript/Data/FYFactionsContractsData.cs
@@ -5,8 +5,8 @@ namespace Prospect.Server.Api.Models.CloudScript.Data;
 public class FYFactionsContractsData
 {
     [JsonPropertyName("boards")]
-    public List<FYFactionContractsData> Boards { get; set; }
+    public List<FYFactionContractsData> Boards { get; set; } = null!;
 
     [JsonPropertyName("lastBoardRefreshTimeUtc")]
-    public FYTimestamp LastBoardRefreshTimeUtc { get; set; }
+    public FYTimestamp LastBoardRefreshTimeUtc { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/CloudScript/Data/FYItemCurrentlyBeingCrafted.cs b/src/Prospect.Server.Api/Models/CloudScript/Data/FYItemCurrentlyBeingCrafted.cs
index 8d0bb78..355f9af 100644
--- a/src/Prospect.Server.Api/Models/CloudScript/Data/FYItemCurrentlyBeingCrafted.cs
+++ b/src/Prospect.Server.Api/Models/CloudScript/Data/FYItemCurrentlyBeingCrafted.cs
@@ -5,7 +5,7 @@ namespace Prospect.Server.Api.Models.CloudScript.Data;
 public class FYItemCurrentlyBeingCrafted
 {
     [JsonPropertyName("itemId")]
-    public string ItemId { get; set; }
+    public string ItemId { get; set; } = null!;
         
     [JsonPropertyName("itemRarity")]
     public int ItemRarity { get; set; }
@@ -14,5 +14,5 @@ public class FYItemCurrentlyBeingCrafted
     public int PurchaseAmount { get; set; }
         
     [JsonPropertyName("utcTimestampWhenCraftingStarted")]
-    public FYTimestamp UtcTimestampWhenCraftingStarted { get; set; }
+    public FYTimestamp UtcTimestampWhenCraftingStarted { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/CloudScript/FYGetCraftingInProgressDataResult.cs b/src/Prospect.Server.Api/Models/CloudScript/FYGetCraftingInProgressDataResult.cs
index 83b6636..eefaa5c 100644
--- a/src/Prospect.Server.Api/Models/CloudScript/FYGetCraftingInProgressDataResult.cs
+++ b/src/Prospect.Server.Api/Models/CloudScript/FYGetCraftingInProgressDataResult.cs
@@ -6,11 +6,11 @@ namespace Prospect.Server.Api.Models.CloudScript;
 public class FYGetCraftingInProgressDataResult
 {
     [JsonPropertyName("userId")]
-    public string UserId { get; set; }
+    public string UserId { get; set; } = null!;
         
     [JsonPropertyName("error")]
-    public string Error { get; set; }
+    public string Error { get; set; } = null!;
         
     [JsonPropertyName("itemCurrentlyBeingCrafted")]
-    public FYItemCurrentlyBeingCrafted ItemCurrentlyBeingCrafted { get; set; }
+    public FYItemCurrentlyBeingCrafted ItemCurrentlyBeingCrafted { get; set; } = null!;
 }
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/CloudScript/FYGetPlayerContractsResult.cs b/src/Prospect.Server.Api/Models/CloudScript/FYGetPlayerContractsResult.cs
index 06574ea..f443b75 100644
--- a/src/Prospect.Server.Api/Models/CloudScript/FYGetPlayerContractsResult.cs
+++ b/src/Prospect.Server.Api/Models/CloudScript/FYGetPlayerContractsResult.cs
@@ -6,16 +6,16 @@ namespace Prospect.Server.Api.Models.CloudScript;
 public class FYGetPlayerContractsResult
 {
     [JsonPropertyName("userId")]
-    public string UserId { get; set; }
+    public string UserId { get; set; } = null!;
 
     [JsonPropertyName("error")]
-    public string Error { get; set; }
+    public string? Error { get; set; }
         
     [JsonPropertyName("activeContracts")]
-    public List<FYActiveContractPlayerData> ActiveContracts { get; set; }
+    public List<FYActiveContractPlayerData> ActiveContracts { get; set; } = null!;
 
     [JsonPropertyName("factionsContracts")]
-    public FYFactionsContractsData FactionsContracts { get; set; }
+    public FYFactionsContractsData FactionsContracts { get; set; } = null!;
 
     [JsonPropertyName("refreshHours24UtcFromBackend")]
     public int RefreshHours24UtcFromBackend { get; set; }
diff --git a/src/Prospect.Server.Api/Models/Multiplayer/Data/FQosServer.cs b/src/Prospect.Server.Api/Models/Multiplayer/Data/FQosServer.cs
new file mode 100644
index 0000000..3c0e7f6
--- /dev/null
+++ b/src/Prospect.Server.Api/Models/Multiplayer/Data/FQosServer.cs
@@ -0,0 +1,20 @@
+using System.Text.Json.Serialization;
+
+namespace Prospect.Server.Api.Models.Multiplayer.Data;
+
+public class FQosServer
+{
+    /// <summary>
+    ///     [optional] The region the QoS server is located in.
+    /// </summary>
+    [JsonPropertyName("Error")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public string? Region { get; set; }
+    
+    /// <summary>
+    ///     [optional] The QoS server URL.
+    /// </summary>
+    [JsonPropertyName("ServerUrl")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public string? ServerUrl { get; set; }
+}
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Multiplayer/FListQosServersForTitleRequest.cs b/src/Prospect.Server.Api/Models/Multiplayer/FListQosServersForTitleRequest.cs
new file mode 100644
index 0000000..9e676d6
--- /dev/null
+++ b/src/Prospect.Server.Api/Models/Multiplayer/FListQosServersForTitleRequest.cs
@@ -0,0 +1,20 @@
+using System.Text.Json.Serialization;
+
+namespace Prospect.Server.Api.Models.Multiplayer;
+
+public class FListQosServersForTitleRequest
+{
+    /// <summary>
+    ///     [optional] The optional custom tags associated with the request (e.g. build number, external trace identifiers, etc.).
+    /// </summary>
+    [JsonPropertyName("CustomTags")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public Dictionary<string, string>? CustomTags { get; set; }
+        
+    /// <summary>
+    ///     [optional] Indicates that the response should contain Qos servers for all regions, including those where there are no builds
+    ///     deployed for the title.
+    /// </summary>
+    [JsonPropertyName("IncludeAllRegions")]
+    public bool? IncludeAllRegions { get; set; }
+}
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Models/Multiplayer/FListQosServersForTitleResponse.cs b/src/Prospect.Server.Api/Models/Multiplayer/FListQosServersForTitleResponse.cs
new file mode 100644
index 0000000..be74e3c
--- /dev/null
+++ b/src/Prospect.Server.Api/Models/Multiplayer/FListQosServersForTitleResponse.cs
@@ -0,0 +1,28 @@
+using System.Text.Json.Serialization;
+using Prospect.Server.Api.Models.Multiplayer.Data;
+
+namespace Prospect.Server.Api.Models.Multiplayer;
+
+public class FListQosServersForTitleResponse
+{
+    /// <summary>
+    ///     The page size on the response.
+    /// </summary>
+    [JsonPropertyName("PageSize")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public int PageSize { get; set; }
+    
+    /// <summary>
+    ///     [optional] The list of QoS servers.
+    /// </summary>
+    [JsonPropertyName("QosServers")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public List<FQosServer>? QosServers { get; set; }
+
+    /// <summary>
+    ///     [optional] The skip token for the paged response.
+    /// </summary>
+    [JsonPropertyName("SkipToken")]
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingDefault)]
+    public string? SkipToken { get; set; }
+}
\ No newline at end of file
diff --git a/src/Prospect.Server.Api/Prospect.Server.Api.csproj b/src/Prospect.Server.Api/Prospect.Server.Api.csproj
index 254641d..ea9e827 100644
--- a/src/Prospect.Server.Api/Prospect.Server.Api.csproj
+++ b/src/Prospect.Server.Api/Prospect.Server.Api.csproj
@@ -3,6 +3,7 @@
     <PropertyGroup>
         <TargetFramework>net6.0</TargetFramework>
         <ImplicitUsings>true</ImplicitUsings>
+        <Nullable>enable</Nullable>
     </PropertyGroup>
 
     <ItemGroup>