Add per-answer thinking disclosure

app/MindWork AI Studio/Provider/OpenAI/AssistantToolCallMessage.cs

@@ -12,5 +12,11 @@ public sealed record AssistantToolCallMessage : IMessageBase
     [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
     public string? ReasoningContent { get; init; }
 
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public string? Reasoning { get; init; }
+
+    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public IList<JsonElement>? ReasoningDetails { get; init; }
+
     public IList<ChatCompletionToolCall> ToolCalls { get; init; } = [];
 }

app/MindWork AI Studio/Provider/OpenAI/ChatCompletionDelta.cs

@@ -13,4 +13,13 @@ public sealed record ChatCompletionDelta
 
     [JsonIgnore]
     public string Content => ChatCompletionContent.GetText(this.RawContent) ?? string.Empty;
+
+    public string? ReasoningContent { get; init; }
+
+    public string? Reasoning { get; init; }
+
+    public IList<JsonElement>? ReasoningDetails { get; init; }
+
+    [JsonIgnore]
+    public string Thinking => ThinkingContent.Get(this.ReasoningContent, this.Reasoning, this.ReasoningDetails);
 }

app/MindWork AI Studio/Provider/OpenAI/ChatCompletionDeltaStreamLine.cs

@@ -19,7 +19,7 @@ public record ChatCompletionDeltaStreamLine(string Id, string Object, uint Creat
     public bool ContainsContent() => this.Choices.Count > 0;
 
     /// <inheritdoc />
-    public ContentStreamChunk GetContent() => new(this.Choices[0].Delta.Content, []);
+    public ContentStreamChunk GetContent() => new(this.Choices[0].Delta.Content, this.Choices[0].Delta.Thinking, []);
 
     #region Implementation of IAnnotationStreamLine
 
@@ -42,4 +42,4 @@ public record ChatCompletionDeltaStreamLine(string Id, string Object, uint Creat
     public IList<ISource> GetSources() => [];
 
     #endregion
-}
+}

app/MindWork AI Studio/Provider/OpenAI/ChatCompletionResponseMessage.cs

@@ -15,5 +15,11 @@ public sealed record ChatCompletionResponseMessage
 
     public string? ReasoningContent { get; init; }
 
+    public string? Reasoning { get; init; }
+
+    public IList<JsonElement>? ReasoningDetails { get; init; }
+
     public IList<ChatCompletionToolCall?>? ToolCalls { get; init; }
+
+    public string GetThinkingOutput() => ThinkingContent.Get(this.ReasoningContent, this.Reasoning, this.ReasoningDetails);
 }

app/MindWork AI Studio/Provider/OpenAI/ChatCompletionToolCallingAdapter.cs

@@ -72,6 +72,7 @@ public sealed class ChatCompletionToolCallingAdapter<TRequest>(
 
         return new ToolCallingRound(
             responseChoice.Message.Content ?? string.Empty,
+            responseChoice.Message.GetThinkingOutput(),
             preparedCalls
                 .Select(x => new ToolCallingRequestedCall(x.ToolCall.Id!, x.ToolCall.Function!.Name!, x.ToolCall.Function!.Arguments!, x.IsValid))
                 .ToList(),
@@ -83,6 +84,8 @@ public sealed class ChatCompletionToolCallingAdapter<TRequest>(
     {
         Content = this.lastResponseMessage?.RawContent,
         ReasoningContent = this.lastResponseMessage?.ReasoningContent,
+        Reasoning = this.lastResponseMessage?.Reasoning,
+        ReasoningDetails = this.lastResponseMessage?.ReasoningDetails,
         ToolCalls = this.lastToolCalls,
     });
 
@@ -168,4 +171,4 @@ public sealed class ChatCompletionToolCallingAdapter<TRequest>(
     }
 
     private readonly record struct PreparedChatCompletionToolCall(ChatCompletionToolCall ToolCall, bool IsValid);
-}
+}

app/MindWork AI Studio/Provider/OpenAI/ResponsesDeltaStreamLine.cs

@@ -15,7 +15,11 @@ public record ResponsesDeltaStreamLine(
     public bool ContainsContent() => this.Delta is not null;
 
     /// <inheritdoc />
-    public ContentStreamChunk GetContent() => new(this.Delta ?? string.Empty, this.GetSources());
+    public ContentStreamChunk GetContent() => this.Type switch
+    {
+        "response.reasoning_summary_text.delta" or "response.reasoning_text.delta" => new(string.Empty, this.Delta ?? string.Empty, this.GetSources()),
+        _ => new(this.Delta ?? string.Empty, string.Empty, this.GetSources()),
+    };
 
     //
     // Please note that there are multiple options where LLM providers might stream sources:
@@ -36,4 +40,4 @@ public record ResponsesDeltaStreamLine(
     public IList<ISource> GetSources() => [];
 
     #endregion
-}
+}

app/MindWork AI Studio/Provider/OpenAI/ResponsesResponse.cs

@@ -42,6 +42,11 @@ public sealed record ResponsesResponse
             }));
     }
 
+    public string GetThinkingOutput() => string.Concat(this.Output
+        .Where(x => ReadString(x, "type").Equals("reasoning", StringComparison.Ordinal))
+        .SelectMany(x => ReadArrayItems(x, "summary").Concat(ReadArrayItems(x, "content")))
+        .Select(x => ReadString(x, "text")));
+
     public IReadOnlyList<Source> GetSources() => this.Output
         .Where(x => ReadString(x, "type").Equals("message", StringComparison.Ordinal))
         .SelectMany(ReadContentItems)

app/MindWork AI Studio/Provider/OpenAI/ResponsesToolCallingAdapter.cs

@@ -57,6 +57,7 @@ public sealed class ResponsesToolCallingAdapter(Model chatModel, IList<object> b
         this.lastResponse = response;
         return new ToolCallingRound(
             response.GetTextOutput(),
+            response.GetThinkingOutput(),
             response.GetFunctionCalls()
                 .Select(call => new ToolCallingRequestedCall(
                     call.CallId ?? string.Empty,
@@ -102,4 +103,4 @@ public sealed class ResponsesToolCallingAdapter(Model chatModel, IList<object> b
             .Concat(runnableTools.Select(x => (object)ProviderToolAdapters.ToResponsesTool(x.Definition)))
             .ToList();
     }
-}
+}

app/MindWork AI Studio/Provider/OpenAI/ThinkingContent.cs

@@ -0,0 +1,46 @@
+using System.Text.Json;
+
+namespace AIStudio.Provider.OpenAI;
+
+/// <summary>
+/// Reads human-readable thinking from OpenAI-compatible response fields.
+/// </summary>
+internal static class ThinkingContent
+{
+    public static string Get(string? reasoningContent, string? reasoning, IEnumerable<JsonElement>? reasoningDetails)
+    {
+        if (!string.IsNullOrWhiteSpace(reasoningContent))
+            return reasoningContent;
+
+        if (!string.IsNullOrWhiteSpace(reasoning))
+            return reasoning;
+
+        if (reasoningDetails is null)
+            return string.Empty;
+
+        return string.Concat(reasoningDetails.Select(GetVisibleDetailText));
+    }
+
+    private static string GetVisibleDetailText(JsonElement detail)
+    {
+        if (detail.ValueKind is not JsonValueKind.Object ||
+            !detail.TryGetProperty("type", out var typeProperty) ||
+            typeProperty.ValueKind is not JsonValueKind.String)
+            return string.Empty;
+
+        return typeProperty.GetString() switch
+        {
+            "reasoning.text" => ReadString(detail, "text"),
+            "reasoning.summary" => ReadString(detail, "summary"),
+            _ => string.Empty,
+        };
+    }
+
+    private static string ReadString(JsonElement item, string propertyName)
+    {
+        if (!item.TryGetProperty(propertyName, out var property) || property.ValueKind is not JsonValueKind.String)
+            return string.Empty;
+
+        return property.GetString() ?? string.Empty;
+    }
+}