diff --git a/internal/translator/antigravity/openai/chat-completions/antigravity_openai_request.go b/internal/translator/antigravity/openai/chat-completions/antigravity_openai_request.go
index baf76eef..7ca01b07 100644
--- a/internal/translator/antigravity/openai/chat-completions/antigravity_openai_request.go
+++ b/internal/translator/antigravity/openai/chat-completions/antigravity_openai_request.go
@@ -184,7 +184,7 @@ func ConvertOpenAIRequestToAntigravity(modelName string, inputRawJSON []byte, _
 			role := m.Get("role").String()
 			content := m.Get("content")
 
-			if role == "system" && len(arr) > 1 {
+			if (role == "system" || role == "developer") && len(arr) > 1 {
 				// system -> request.systemInstruction as a user message style
 				if content.Type == gjson.String {
 					out, _ = sjson.SetBytes(out, "request.systemInstruction.role", "user")
@@ -201,7 +201,7 @@ func ConvertOpenAIRequestToAntigravity(modelName string, inputRawJSON []byte, _
 						}
 					}
 				}
-			} else if role == "user" || (role == "system" && len(arr) == 1) {
+			} else if role == "user" || ((role == "system" || role == "developer") && len(arr) == 1) {
 				// Build single user content node to avoid splitting into multiple contents
 				node := []byte(`{"role":"user","parts":[]}`)
 				if content.Type == gjson.String {
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 c511644d..98188835 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
@@ -152,7 +152,7 @@ func ConvertOpenAIRequestToGeminiCLI(modelName string, inputRawJSON []byte, _ bo
 			role := m.Get("role").String()
 			content := m.Get("content")
 
-			if role == "system" && len(arr) > 1 {
+			if (role == "system" || role == "developer") && len(arr) > 1 {
 				// system -> request.systemInstruction as a user message style
 				if content.Type == gjson.String {
 					out, _ = sjson.SetBytes(out, "request.systemInstruction.role", "user")
@@ -169,7 +169,7 @@ func ConvertOpenAIRequestToGeminiCLI(modelName string, inputRawJSON []byte, _ bo
 						}
 					}
 				}
-			} else if role == "user" || (role == "system" && len(arr) == 1) {
+			} else if role == "user" || ((role == "system" || role == "developer") && len(arr) == 1) {
 				// Build single user content node to avoid splitting into multiple contents
 				node := []byte(`{"role":"user","parts":[]}`)
 				if content.Type == gjson.String {
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 5c96b847..57e150c1 100644
--- a/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
+++ b/internal/translator/gemini/openai/chat-completions/gemini_openai_request.go
@@ -170,7 +170,7 @@ func ConvertOpenAIRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 			role := m.Get("role").String()
 			content := m.Get("content")
 
-			if role == "system" && len(arr) > 1 {
+			if (role == "system" || role == "developer") && len(arr) > 1 {
 				// system -> system_instruction as a user message style
 				if content.Type == gjson.String {
 					out, _ = sjson.SetBytes(out, "system_instruction.role", "user")
@@ -187,7 +187,7 @@ func ConvertOpenAIRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 						}
 					}
 				}
-			} else if role == "user" || (role == "system" && len(arr) == 1) {
+			} else if role == "user" || ((role == "system" || role == "developer") && len(arr) == 1) {
 				// Build single user content node to avoid splitting into multiple contents
 				node := []byte(`{"role":"user","parts":[]}`)
 				if content.Type == gjson.String {