Add reasoning/thinking configuration handling for Claude and OpenAI translators

- Implemented `thinkingConfig` handling to allow reasoning effort configuration in request generation.
- Added support for reasoning content deltas (`thinking_delta`) in response processing.
- Enhanced reasoning-related token budget mappings for various reasoning levels.
- Improved response handling logic to ensure proper reasoning content inclusion.

internal/translator/claude/gemini/claude_gemini_request.go

@@ -89,6 +89,17 @@ func ConvertGeminiRequestToClaude(modelName string, inputRawJSON []byte, stream
 				out, _ = sjson.Set(out, "stop_sequences", stopSequences)
 			}
 		}
+		// Include thoughts configuration for reasoning process visibility
+		if thinkingConfig := genConfig.Get("thinkingConfig"); thinkingConfig.Exists() && thinkingConfig.IsObject() {
+			if includeThoughts := thinkingConfig.Get("include_thoughts"); includeThoughts.Exists() {
+				if includeThoughts.Type == gjson.True {
+					out, _ = sjson.Set(out, "thinking.type", "enabled")
+					if thinkingBudget := thinkingConfig.Get("thinkingBudget"); thinkingBudget.Exists() {
+						out, _ = sjson.Set(out, "thinking.budget_tokens", thinkingBudget.Int())
+					}
+				}
+			}
+		}
 	}
 
 	// System instruction conversion to Claude Code format

internal/translator/claude/gemini/claude_gemini_response.go

@@ -128,7 +128,7 @@ func ConvertClaudeResponseToGemini(_ context.Context, modelName string, original
 				}
 			case "thinking_delta":
 				// Thinking/reasoning content delta for models with reasoning capabilities
-				if text := delta.Get("text"); text.Exists() && text.String() != "" {
+				if text := delta.Get("thinking"); text.Exists() && text.String() != "" {
 					thinkingPart := `{"thought":true,"text":""}`
 					thinkingPart, _ = sjson.Set(thinkingPart, "text", text.String())
 					template, _ = sjson.SetRaw(template, "candidates.0.content.parts.-1", thinkingPart)
@@ -411,7 +411,7 @@ func ConvertClaudeResponseToGeminiNonStream(_ context.Context, modelName string,
 					}
 				case "thinking_delta":
 					// Process reasoning/thinking content
-					if text := delta.Get("text"); text.Exists() && text.String() != "" {
+					if text := delta.Get("thinking"); text.Exists() && text.String() != "" {
 						partJSON := `{"thought":true,"text":""}`
 						partJSON, _ = sjson.Set(partJSON, "text", text.String())
 						part := gjson.Parse(partJSON).Value().(map[string]interface{})

internal/translator/claude/openai/chat-completions/claude_openai_request.go

@@ -41,6 +41,21 @@ func ConvertOpenAIRequestToClaude(modelName string, inputRawJSON []byte, stream
 
 	root := gjson.ParseBytes(rawJSON)
 
+	if v := root.Get("reasoning_effort"); v.Exists() {
+		out, _ = sjson.Set(out, "thinking.type", "enabled")
+
+		switch v.String() {
+		case "none":
+			out, _ = sjson.Set(out, "thinking.type", "disabled")
+		case "low":
+			out, _ = sjson.Set(out, "thinking.budget_tokens", 1024)
+		case "medium":
+			out, _ = sjson.Set(out, "thinking.budget_tokens", 8192)
+		case "high":
+			out, _ = sjson.Set(out, "thinking.budget_tokens", 24576)
+		}
+	}
+
 	// Helper for generating tool call IDs in the form: toolu_<alphanum>
 	// This ensures unique identifiers for tool calls in the Claude Code format
 	genToolCallID := func() string {

internal/translator/claude/openai/chat-completions/claude_openai_response.go

@@ -128,10 +128,11 @@ func ConvertClaudeResponseToOpenAI(_ context.Context, modelName string, original
 				return []string{}
 			}
 		}
-		return []string{template}
+		return []string{}
 
 	case "content_block_delta":
 		// Handle content delta (text, tool use arguments, or reasoning content)
+		hasContent := false
 		if delta := root.Get("delta"); delta.Exists() {
 			deltaType := delta.Get("type").String()
 
@@ -140,8 +141,14 @@ func ConvertClaudeResponseToOpenAI(_ context.Context, modelName string, original
 				// Text content delta - send incremental text updates
 				if text := delta.Get("text"); text.Exists() {
 					template, _ = sjson.Set(template, "choices.0.delta.content", text.String())
+					hasContent = true
+				}
+			case "thinking_delta":
+				// Accumulate reasoning/thinking content
+				if thinking := delta.Get("thinking"); thinking.Exists() {
+					template, _ = sjson.Set(template, "choices.0.delta.reasoning_content", thinking.String())
+					hasContent = true
 				}
-
 			case "input_json_delta":
 				// Tool use input delta - accumulate arguments for tool calls
 				if partialJSON := delta.Get("partial_json"); partialJSON.Exists() {
@@ -156,7 +163,11 @@ func ConvertClaudeResponseToOpenAI(_ context.Context, modelName string, original
 				return []string{}
 			}
 		}
-		return []string{template}
+		if hasContent {
+			return []string{template}
+		} else {
+			return []string{}
+		}
 
 	case "content_block_stop":
 		// End of content block - output complete tool call if it's a tool_use block

internal/translator/claude/openai/responses/claude_openai-responses_request.go

@@ -28,6 +28,23 @@ func ConvertOpenAIResponsesRequestToClaude(modelName string, inputRawJSON []byte
 
 	root := gjson.ParseBytes(rawJSON)
 
+	if v := root.Get("reasoning.effort"); v.Exists() {
+		out, _ = sjson.Set(out, "thinking.type", "enabled")
+
+		switch v.String() {
+		case "none":
+			out, _ = sjson.Set(out, "thinking.type", "disabled")
+		case "minimal":
+			out, _ = sjson.Set(out, "thinking.budget_tokens", 1024)
+		case "low":
+			out, _ = sjson.Set(out, "thinking.budget_tokens", 4096)
+		case "medium":
+			out, _ = sjson.Set(out, "thinking.budget_tokens", 8192)
+		case "high":
+			out, _ = sjson.Set(out, "thinking.budget_tokens", 24576)
+		}
+	}
+
 	// Helper for generating tool call IDs when missing
 	genToolCallID := func() string {
 		const letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"