Add Reasoning Effort Support

src/Primitives/CrestApps.Core.AI.Claude/Handlers/ClaudeChatInteractionSettingsHandler.cs

@@ -19,6 +19,7 @@ public Task UpdatingAsync(ChatInteraction interaction, JsonElement settings)
         interaction.Alter<ClaudeSessionMetadata>(metadata =>
         {
             metadata.ClaudeModel = GetString(settings, "anthropicModel");
+            metadata.EffortLevel = GetEnum<ClaudeEffortLevel>(settings, "anthropicEffortLevel");
         });
 
         return Task.CompletedTask;
@@ -38,4 +39,22 @@ private static string GetString(JsonElement element, string propertyName)
 
         return null;
     }
+
+    private static T GetEnum<T>(JsonElement element, string propertyName) where T : struct, Enum
+    {
+        if (element.TryGetProperty(propertyName, out var prop))
+        {
+            if (prop.ValueKind == JsonValueKind.Number && Enum.IsDefined(typeof(T), prop.GetInt32()))
+            {
+                return (T)(object)prop.GetInt32();
+            }
+
+            if (prop.ValueKind == JsonValueKind.String && Enum.TryParse<T>(prop.GetString(), ignoreCase: true, out var result))
+            {
+                return result;
+            }
+        }
+
+        return default;
+    }
 }

src/Primitives/CrestApps.Core.AI.Claude/Models/ClaudeEffortLevel.cs

@@ -0,0 +1,28 @@
+namespace CrestApps.Core.AI.Claude.Models;
+
+/// <summary>
+/// The reasoning effort level for Anthropic extended thinking.
+/// Maps to the <c>budget_tokens</c> parameter.
+/// </summary>
+public enum ClaudeEffortLevel
+{
+    /// <summary>
+    /// No effort level specified; the API default is used.
+    /// </summary>
+    None = 0,
+
+    /// <summary>
+    /// Low reasoning effort.
+    /// </summary>
+    Low = 1,
+
+    /// <summary>
+    /// Medium reasoning effort.
+    /// </summary>
+    Medium = 2,
+
+    /// <summary>
+    /// High reasoning effort.
+    /// </summary>
+    High = 3,
+}

src/Primitives/CrestApps.Core.AI.Claude/Models/ClaudeSessionMetadata.cs

@@ -10,4 +10,9 @@ public sealed class ClaudeSessionMetadata
     /// The Anthropic model override for the session.
     /// </summary>
     public string ClaudeModel { get; set; }
+
+    /// <summary>
+    /// The reasoning effort level for the session.
+    /// </summary>
+    public ClaudeEffortLevel EffortLevel { get; set; }
 }

src/Primitives/CrestApps.Core.AI.Claude/Services/ClaudeOrchestrator.cs

@@ -60,6 +60,7 @@ public async IAsyncEnumerable<ChatResponseUpdate> ExecuteStreamingAsync(
         var modelId = !string.IsNullOrWhiteSpace(metadata?.ClaudeModel)
             ? metadata.ClaudeModel
             : null;
+        var effortLevel = metadata?.EffortLevel ?? ClaudeEffortLevel.None;
         var anthropicOptions = _anthropicOptions.Value;
         modelId ??= anthropicOptions.DefaultModel;
 
@@ -90,7 +91,7 @@ public async IAsyncEnumerable<ChatResponseUpdate> ExecuteStreamingAsync(
         });
 
         var configuredClient = builder.Build(context.ServiceProvider);
-        var chatOptions = BuildChatOptions(context.CompletionContext, modelId);
+        var chatOptions = BuildChatOptions(context.CompletionContext, modelId, effortLevel);
         var prompts = BuildPrompts(context);
         ChatResponseUpdate errorResponse = null;
 
@@ -134,9 +135,9 @@ private static bool IsConfigured(ClaudeOptions options)
             !string.IsNullOrWhiteSpace(options.DefaultModel);
     }
 
-    private static ChatOptions BuildChatOptions(AICompletionContext context, string modelId)
+    private static ChatOptions BuildChatOptions(AICompletionContext context, string modelId, ClaudeEffortLevel effortLevel)
     {
-        return new ChatOptions
+        var options = new ChatOptions
         {
             ModelId = modelId,
             Temperature = context.Temperature,
@@ -145,6 +146,25 @@ private static ChatOptions BuildChatOptions(AICompletionContext context, string
             PresencePenalty = context.PresencePenalty,
             MaxOutputTokens = context.MaxTokens,
         };
+
+        if (effortLevel != ClaudeEffortLevel.None)
+        {
+            var effortValue = effortLevel switch
+            {
+                ClaudeEffortLevel.Low => "low",
+                ClaudeEffortLevel.Medium => "medium",
+                ClaudeEffortLevel.High => "high",
+                _ => null,
+            };
+
+            if (effortValue is not null)
+            {
+                options.AdditionalProperties ??= [];
+                options.AdditionalProperties["reasoning_effort"] = effortValue;
+            }
+        }
+
+        return options;
     }
 
     private static List<ChatMessage> BuildPrompts(OrchestrationContext context)

src/Primitives/CrestApps.Core.AI.Copilot/Handlers/CopilotChatInteractionSettingsHandler.cs

@@ -26,6 +26,7 @@ public Task UpdatingAsync(ChatInteraction interaction, JsonElement settings)
         {
             metadata.CopilotModel = copilotModel;
             metadata.IsAllowAll = isAllowAll;
+            metadata.ReasoningEffort = GetEnum<CopilotReasoningEffort>(settings, "copilotReasoningEffort");
         });
         return Task.CompletedTask;
     }
@@ -62,4 +63,22 @@ private static bool GetBool(JsonElement element, string propertyName)
 
         return false;
     }
+
+    private static T GetEnum<T>(JsonElement element, string propertyName) where T : struct, Enum
+    {
+        if (element.TryGetProperty(propertyName, out var prop))
+        {
+            if (prop.ValueKind == JsonValueKind.Number && Enum.IsDefined(typeof(T), prop.GetInt32()))
+            {
+                return (T)(object)prop.GetInt32();
+            }
+
+            if (prop.ValueKind == JsonValueKind.String && Enum.TryParse<T>(prop.GetString(), true, out var result))
+            {
+                return result;
+            }
+        }
+
+        return default;
+    }
 }

src/Primitives/CrestApps.Core.AI.Copilot/Models/CopilotModelInfo.cs

@@ -14,4 +14,10 @@ public sealed class CopilotModelInfo
     /// The display name of the model.
     /// </summary>
     public string Name { get; set; }
+
+    /// <summary>
+    /// The premium request cost multiplier (e.g., 1 for standard, 0.33 for discounted, 3 for premium).
+    /// A value of <c>0</c> means unknown.
+    /// </summary>
+    public double CostMultiplier { get; set; }
 }

src/Primitives/CrestApps.Core.AI.Copilot/Models/CopilotReasoningEffort.cs

@@ -0,0 +1,27 @@
+namespace CrestApps.Core.AI.Copilot.Models;
+
+/// <summary>
+/// The reasoning effort level for GitHub Copilot sessions.
+/// </summary>
+public enum CopilotReasoningEffort
+{
+    /// <summary>
+    /// No explicit effort level; use the model default.
+    /// </summary>
+    None = 0,
+
+    /// <summary>
+    /// Low reasoning effort.
+    /// </summary>
+    Low = 1,
+
+    /// <summary>
+    /// Medium reasoning effort.
+    /// </summary>
+    Medium = 2,
+
+    /// <summary>
+    /// High reasoning effort.
+    /// </summary>
+    High = 3,
+}

src/Primitives/CrestApps.Core.AI.Copilot/Models/CopilotSessionMetadata.cs

@@ -40,4 +40,9 @@ public sealed class CopilotSessionMetadata
     /// When the access token expires.
     /// </summary>
     public DateTime? ExpiresAt { get; set; }
+
+    /// <summary>
+    /// The reasoning effort level for the session.
+    /// </summary>
+    public CopilotReasoningEffort ReasoningEffort { get; set; }
 }

src/Primitives/CrestApps.Core.AI.Copilot/Services/CopilotOrchestrator.cs

@@ -103,6 +103,7 @@ public async IAsyncEnumerable<ChatResponseUpdate> ExecuteStreamingAsync(Orchestr
         {
             metadata = md;
             sessionConfig.Model = metadata.CopilotModel;
+            sessionConfig.ReasoningEffort = GetReasoningEffortValue(metadata.ReasoningEffort);
             sessionConfig.OnPermissionRequest = CreatePermissionRequestHandler(metadata.IsAllowAll);
         }
 
@@ -267,6 +268,17 @@ private static PermissionRequestHandler CreatePermissionRequestHandler(bool allo
         return (request, invocation) => Task.FromResult(new PermissionRequestResult { Kind = PermissionRequestResultKind.DeniedCouldNotRequestFromUser, });
     }
 
+    private static string GetReasoningEffortValue(CopilotReasoningEffort reasoningEffort)
+    {
+        return reasoningEffort switch
+        {
+            CopilotReasoningEffort.Low => "low",
+            CopilotReasoningEffort.Medium => "medium",
+            CopilotReasoningEffort.High => "high",
+            _ => null,
+        };
+    }
+
     /// <summary>
     /// Configures the BYOK provider on the session config using the options.
     /// </summary>

src/Primitives/CrestApps.Core.AI.Copilot/Services/GitHubOAuthService.cs

@@ -283,6 +283,7 @@ public async Task<IReadOnlyCollection<CopilotModelInfo>> ListModelsAsync(
                 {
                     Id = m.Id,
                     Name = !string.IsNullOrEmpty(m.Name) ? m.Name : m.Id,
+                    CostMultiplier = m.Billing?.Multiplier ?? 0,
                 })
                 .ToList();
         }

src/Startup/CrestApps.Core.Mvc.Web/Areas/AI/Controllers/AIProfileController.cs

@@ -249,7 +249,7 @@ private async Task PopulateDropdownsAsync(AIProfileViewModel model)
                     var cred = await _oauthService.GetCredentialAsync(userId);
                     model.CopilotGitHubUsername = cred?.GitHubUsername;
                     var models = await _oauthService.ListModelsAsync(userId);
-                    model.CopilotAvailableModels = models.Select(m => new SelectListItem(m.Name, m.Id)).ToList();
+                    model.CopilotAvailableModels = models.Select(m => new SelectListItem(FormatCopilotModelName(m), m.Id)).ToList();
                 }
             }
         }
@@ -428,7 +428,7 @@ private static void ApplyTemplateToProfile(AIProfile profile, AIProfileTemplate
 
         if (template.TryGet<CopilotSessionMetadata>(out var copilotMetadata))
         {
-            profile.Put(new CopilotSessionMetadata { CopilotModel = copilotMetadata.CopilotModel, IsAllowAll = copilotMetadata.IsAllowAll, });
+            profile.Put(new CopilotSessionMetadata { CopilotModel = copilotMetadata.CopilotModel, ReasoningEffort = copilotMetadata.ReasoningEffort, IsAllowAll = copilotMetadata.IsAllowAll, });
         }
         else
         {
@@ -437,7 +437,7 @@ private static void ApplyTemplateToProfile(AIProfile profile, AIProfileTemplate
 
         if (template.TryGet<ClaudeSessionMetadata>(out var anthropicMetadata))
         {
-            profile.Put(new ClaudeSessionMetadata { ClaudeModel = anthropicMetadata.ClaudeModel, });
+            profile.Put(new ClaudeSessionMetadata { ClaudeModel = anthropicMetadata.ClaudeModel, EffortLevel = anthropicMetadata.EffortLevel, });
         }
         else
         {
@@ -486,4 +486,13 @@ private async Task PopulateClaudeModelsAsync(AIProfileViewModel model)
     }
 
     private bool IsCopilotConfigured() => _copilotOptions.IsConfigured();
+
+    private static string FormatCopilotModelName(CopilotModelInfo model)
+    {
+        var name = !string.IsNullOrWhiteSpace(model.Name) ? model.Name : model.Id;
+
+        return model.CostMultiplier > 0
+            ? $"{name} (x{model.CostMultiplier.ToString("0.##", System.Globalization.CultureInfo.InvariantCulture)})"
+            : name;
+    }
 }

src/Startup/CrestApps.Core.Mvc.Web/Areas/AI/Controllers/AITemplateController.cs

@@ -1,3 +1,4 @@
+using System.Globalization;
 using CrestApps.Core.AI;
 using CrestApps.Core.AI.A2A.Models;
 using CrestApps.Core.AI.Claude.Models;
@@ -337,8 +338,17 @@ private async Task PopulateCopilotStatusAsync(AITemplateViewModel model)
         var credential = await _oauthService.GetCredentialAsync(userId);
         model.CopilotGitHubUsername = credential?.GitHubUsername;
         var models = await _oauthService.ListModelsAsync(userId);
-        model.CopilotAvailableModels = models.Select(m => new SelectListItem(m.Name, m.Id)).ToList();
+        model.CopilotAvailableModels = models.Select(m => new SelectListItem(FormatCopilotModelName(m), m.Id)).ToList();
     }
 
     private bool IsCopilotConfigured() => _copilotOptions.IsConfigured();
+
+    private static string FormatCopilotModelName(CopilotModelInfo model)
+    {
+        var name = !string.IsNullOrWhiteSpace(model.Name) ? model.Name : model.Id;
+
+        return model.CostMultiplier > 0
+            ? $"{name} (x{model.CostMultiplier.ToString("0.##", CultureInfo.InvariantCulture)})"
+            : name;
+    }
 }

src/Startup/CrestApps.Core.Mvc.Web/Areas/AI/ViewModels/AIProfileViewModel.cs

@@ -138,11 +138,15 @@ public sealed class AIProfileViewModel
     // Anthropic
     public string ClaudeModel { get; set; }
 
+    public ClaudeEffortLevel ClaudeEffortLevel { get; set; }
+
     public bool ClaudeIsConfigured { get; set; }
 
     // Copilot
     public string CopilotModel { get; set; }
 
+    public CopilotReasoningEffort CopilotReasoningEffort { get; set; }
+
     public bool CopilotIsAllowAll { get; set; }
 
     public bool CopilotIsConfigured { get; set; }
@@ -337,12 +341,14 @@ public static AIProfileViewModel FromProfile(AIProfile profile)
         if (profile.TryGet<CopilotSessionMetadata>(out var copilotMeta))
         {
             vm.CopilotModel = copilotMeta.CopilotModel;
+            vm.CopilotReasoningEffort = copilotMeta.ReasoningEffort;
             vm.CopilotIsAllowAll = copilotMeta.IsAllowAll;
         }
 
         if (profile.TryGet<ClaudeSessionMetadata>(out var anthropicMeta))
         {
             vm.ClaudeModel = anthropicMeta.ClaudeModel;
+            vm.ClaudeEffortLevel = anthropicMeta.EffortLevel;
         }
 
         return vm;
@@ -549,6 +555,7 @@ public void ApplyTo(AIProfile profile)
             profile.Alter<ClaudeSessionMetadata>(metadata =>
             {
                 metadata.ClaudeModel = ClaudeModel;
+                metadata.EffortLevel = ClaudeEffortLevel;
             });
         }
         else
@@ -563,6 +570,7 @@ public void ApplyTo(AIProfile profile)
             profile.Alter<CopilotSessionMetadata>(metadata =>
             {
                 metadata.CopilotModel = CopilotModel;
+                metadata.ReasoningEffort = CopilotReasoningEffort;
                 metadata.IsAllowAll = CopilotIsAllowAll;
             });
         }

src/Startup/CrestApps.Core.Mvc.Web/Areas/AI/ViewModels/AITemplateViewModel.cs

@@ -120,6 +120,8 @@ public sealed class AITemplateViewModel
     // Anthropic.
     public string ClaudeModel { get; set; }
 
+    public ClaudeEffortLevel ClaudeEffortLevel { get; set; }
+
     public bool ClaudeIsConfigured { get; set; }
 
     // Settings.
@@ -129,6 +131,8 @@ public sealed class AITemplateViewModel
     // Copilot.
     public string CopilotModel { get; set; }
 
+    public CopilotReasoningEffort CopilotReasoningEffort { get; set; }
+
     public bool CopilotIsAllowAll { get; set; }
 
     public bool CopilotIsConfigured { get; set; }
@@ -312,12 +316,14 @@ public static AITemplateViewModel FromTemplate(AIProfileTemplate template)
             if (template.TryGet<CopilotSessionMetadata>(out var copilotMetadata))
             {
                 model.CopilotModel = copilotMetadata.CopilotModel;
+                model.CopilotReasoningEffort = copilotMetadata.ReasoningEffort;
                 model.CopilotIsAllowAll = copilotMetadata.IsAllowAll;
             }
 
             if (template.TryGet<ClaudeSessionMetadata>(out var anthropicMetadata))
             {
                 model.ClaudeModel = anthropicMetadata.ClaudeModel;
+                model.ClaudeEffortLevel = anthropicMetadata.EffortLevel;
             }
         }
 
@@ -522,6 +528,7 @@ public void ApplyTo(AIProfileTemplate template)
                 template.Put(new ClaudeSessionMetadata
                 {
                     ClaudeModel = ClaudeModel,
+                    EffortLevel = ClaudeEffortLevel,
                 });
             }
             else
@@ -535,6 +542,7 @@ public void ApplyTo(AIProfileTemplate template)
                 template.Put(new CopilotSessionMetadata
                 {
                     CopilotModel = CopilotModel,
+                    ReasoningEffort = CopilotReasoningEffort,
                     IsAllowAll = CopilotIsAllowAll,
                 });
             }