Fixed: #1398

fix(translator): use model group caching for client signature validation

internal/translator/antigravity/claude/antigravity_claude_request.go

@@ -115,7 +115,7 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 							if signatureResult.Exists() && signatureResult.String() != "" {
 								arrayClientSignatures := strings.SplitN(signatureResult.String(), "#", 2)
 								if len(arrayClientSignatures) == 2 {
-									if modelName == arrayClientSignatures[0] {
+									if cache.GetModelGroup(modelName) == arrayClientSignatures[0] {
 										clientSignature = arrayClientSignatures[1]
 									}
 								}

internal/translator/codex/openai/responses/codex_openai-responses_request.go

@@ -11,6 +11,12 @@ import (
 func ConvertOpenAIResponsesRequestToCodex(modelName string, inputRawJSON []byte, _ bool) []byte {
 	rawJSON := bytes.Clone(inputRawJSON)
 
+	inputResult := gjson.GetBytes(rawJSON, "input")
+	if inputResult.Type == gjson.String {
+		input, _ := sjson.Set(`[{"type":"message","role":"user","content":[{"type":"input_text","text":""}]}]`, "0.content.0.text", inputResult.String())
+		rawJSON, _ = sjson.SetRawBytes(rawJSON, "input", []byte(input))
+	}
+
 	rawJSON, _ = sjson.SetBytes(rawJSON, "stream", true)
 	rawJSON, _ = sjson.SetBytes(rawJSON, "store", false)
 	rawJSON, _ = sjson.SetBytes(rawJSON, "parallel_tool_calls", true)

internal/translator/openai/openai/responses/openai_openai-responses_request.go

@@ -68,6 +68,9 @@ func ConvertOpenAIResponsesRequestToOpenAIChatCompletions(modelName string, inpu
 			case "message", "":
 				// Handle regular message conversion
 				role := item.Get("role").String()
+				if role == "developer" {
+					role = "user"
+				}
 				message := `{"role":"","content":""}`
 				message, _ = sjson.Set(message, "role", role)
 
@@ -167,7 +170,8 @@ func ConvertOpenAIResponsesRequestToOpenAIChatCompletions(modelName string, inpu
 			// Only function tools need structural conversion because Chat Completions nests details under "function".
 			toolType := tool.Get("type").String()
 			if toolType != "" && toolType != "function" && tool.IsObject() {
-				chatCompletionsTools = append(chatCompletionsTools, tool.Value())
+				// Almost all providers lack built-in tools, so we just ignore them.
+				// chatCompletionsTools = append(chatCompletionsTools, tool.Value())
 				return true
 			}