diff --git a/internal/translator/gemini-cli/openai/chat-completions/gemini-cli_openai_request.go b/internal/translator/gemini-cli/openai/chat-completions/gemini-cli_openai_request.go
index 5da6c2c6..a5edbcae 100644
--- a/internal/translator/gemini-cli/openai/chat-completions/gemini-cli_openai_request.go
+++ b/internal/translator/gemini-cli/openai/chat-completions/gemini-cli_openai_request.go
@@ -33,8 +33,10 @@ func ConvertOpenAIRequestToGeminiCLI(modelName string, inputRawJSON []byte, _ bo
 	out, _ = sjson.SetBytes(out, "model", modelName)
 
 	// Reasoning effort -> thinkingBudget/include_thoughts
+	// Note: OpenAI official fields take precedence over extra_body.google.thinking_config
 	re := gjson.GetBytes(rawJSON, "reasoning_effort")
-	if re.Exists() && util.ModelSupportsThinking(modelName) {
+	hasOfficialThinking := re.Exists()
+	if hasOfficialThinking && util.ModelSupportsThinking(modelName) {
 		switch re.String() {
 		case "none":
 			out, _ = sjson.DeleteBytes(out, "request.generationConfig.thinkingConfig.include_thoughts")
@@ -52,6 +54,19 @@ func ConvertOpenAIRequestToGeminiCLI(modelName string, inputRawJSON []byte, _ bo
 		}
 	}
 
+	// Cherry Studio extension extra_body.google.thinking_config (effective only when official fields are absent)
+	if !hasOfficialThinking && util.ModelSupportsThinking(modelName) {
+		if tc := gjson.GetBytes(rawJSON, "extra_body.google.thinking_config"); tc.Exists() && tc.IsObject() {
+			if v := tc.Get("thinking_budget"); v.Exists() {
+				budget := util.NormalizeThinkingBudget(modelName, int(v.Int()))
+				out, _ = sjson.SetBytes(out, "request.generationConfig.thinkingConfig.thinkingBudget", budget)
+			}
+			if v := tc.Get("include_thoughts"); v.Exists() {
+				out, _ = sjson.SetBytes(out, "request.generationConfig.thinkingConfig.include_thoughts", v.Bool())
+			}
+		}
+	}
+
 	// Temperature/top_p/top_k
 	if tr := gjson.GetBytes(rawJSON, "temperature"); tr.Exists() && tr.Type == gjson.Number {
 		out, _ = sjson.SetBytes(out, "request.generationConfig.temperature", tr.Num)
diff --git a/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go b/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
index f89ec16a..b842569d 100644
--- a/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
+++ b/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
@@ -33,8 +33,10 @@ func ConvertOpenAIRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 	out, _ = sjson.SetBytes(out, "model", modelName)
 
 	// Reasoning effort -> thinkingBudget/include_thoughts
+	// Note: OpenAI official fields take precedence over extra_body.google.thinking_config
 	re := gjson.GetBytes(rawJSON, "reasoning_effort")
-	if re.Exists() && util.ModelSupportsThinking(modelName) {
+	hasOfficialThinking := re.Exists()
+	if hasOfficialThinking && util.ModelSupportsThinking(modelName) {
 		switch re.String() {
 		case "none":
 			out, _ = sjson.DeleteBytes(out, "generationConfig.thinkingConfig.include_thoughts")
@@ -52,6 +54,20 @@ func ConvertOpenAIRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 		}
 	}
 
+	// Cherry Studio extension extra_body.google.thinking_config (effective only when official fields are absent)
+	if !hasOfficialThinking && util.ModelSupportsThinking(modelName) {
+		if tc := gjson.GetBytes(rawJSON, "extra_body.google.thinking_config"); tc.Exists() && tc.IsObject() {
+			if v := tc.Get("thinking_budget"); v.Exists() {
+				// Normalize budget to model range
+				budget := util.NormalizeThinkingBudget(modelName, int(v.Int()))
+				out, _ = sjson.SetBytes(out, "generationConfig.thinkingConfig.thinkingBudget", budget)
+			}
+			if v := tc.Get("include_thoughts"); v.Exists() {
+				out, _ = sjson.SetBytes(out, "generationConfig.thinkingConfig.include_thoughts", v.Bool())
+			}
+		}
+	}
+
 	// Temperature/top_p/top_k
 	if tr := gjson.GetBytes(rawJSON, "temperature"); tr.Exists() && tr.Type == gjson.Number {
 		out, _ = sjson.SetBytes(out, "generationConfig.temperature", tr.Num)
diff --git a/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go b/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go
index b54c2730..7f14280d 100644
--- a/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go
+++ b/internal/translator/gemini/openai/responses/gemini_openai-responses_request.go
@@ -243,7 +243,10 @@ func ConvertOpenAIResponsesRequestToGemini(modelName string, inputRawJSON []byte
 		out, _ = sjson.Set(out, "generationConfig.stopSequences", sequences)
 	}
 
-	if reasoningEffort := root.Get("reasoning.effort"); reasoningEffort.Exists() && util.ModelSupportsThinking(modelName) {
+	// OpenAI official reasoning fields take precedence
+	hasOfficialThinking := root.Get("reasoning.effort").Exists()
+	if hasOfficialThinking && util.ModelSupportsThinking(modelName) {
+		reasoningEffort := root.Get("reasoning.effort")
 		switch reasoningEffort.String() {
 		case "none":
 			out, _ = sjson.Set(out, "generationConfig.thinkingConfig.include_thoughts", false)
@@ -262,5 +265,18 @@ func ConvertOpenAIResponsesRequestToGemini(modelName string, inputRawJSON []byte
 			out, _ = sjson.Set(out, "generationConfig.thinkingConfig.thinkingBudget", -1)
 		}
 	}
+
+	// Cherry Studio extension (applies only when official fields are missing)
+	if !hasOfficialThinking && util.ModelSupportsThinking(modelName) {
+		if tc := root.Get("extra_body.google.thinking_config"); tc.Exists() && tc.IsObject() {
+			if v := tc.Get("thinking_budget"); v.Exists() {
+				budget := util.NormalizeThinkingBudget(modelName, int(v.Int()))
+				out, _ = sjson.Set(out, "generationConfig.thinkingConfig.thinkingBudget", budget)
+			}
+			if v := tc.Get("include_thoughts"); v.Exists() {
+				out, _ = sjson.Set(out, "generationConfig.thinkingConfig.include_thoughts", v.Bool())
+			}
+		}
+	}
 	return []byte(out)
 }