fix(translators): handle string system instructions in Claude translators

Updated Antigravity, Gemini, and Gemini-CLI translators to process `systemResult` of type `string` for system instructions. Ensures properly formatted JSON with dynamic content assignment.

internal/runtime/executor/antigravity_executor.go

@@ -32,18 +32,18 @@ import (
 )
 
 const (
-	antigravityBaseURLDaily = "https://daily-cloudcode-pa.sandbox.googleapis.com"
-	// antigravityBaseURLAutopush     = "https://autopush-cloudcode-pa.sandbox.googleapis.com"
-	antigravityBaseURLProd     = "https://cloudcode-pa.googleapis.com"
-	antigravityCountTokensPath = "/v1internal:countTokens"
-	antigravityStreamPath      = "/v1internal:streamGenerateContent"
-	antigravityGeneratePath    = "/v1internal:generateContent"
-	antigravityModelsPath      = "/v1internal:fetchAvailableModels"
-	antigravityClientID        = "1071006060591-tmhssin2h21lcre235vtolojh4g403ep.apps.googleusercontent.com"
-	antigravityClientSecret    = "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"
-	defaultAntigravityAgent    = "antigravity/1.11.5 windows/amd64"
-	antigravityAuthType        = "antigravity"
-	refreshSkew                = 3000 * time.Second
+	antigravityBaseURLDaily        = "https://daily-cloudcode-pa.googleapis.com"
+	antigravitySandboxBaseURLDaily = "https://daily-cloudcode-pa.sandbox.googleapis.com"
+	antigravityBaseURLProd         = "https://cloudcode-pa.googleapis.com"
+	antigravityCountTokensPath     = "/v1internal:countTokens"
+	antigravityStreamPath          = "/v1internal:streamGenerateContent"
+	antigravityGeneratePath        = "/v1internal:generateContent"
+	antigravityModelsPath          = "/v1internal:fetchAvailableModels"
+	antigravityClientID            = "1071006060591-tmhssin2h21lcre235vtolojh4g403ep.apps.googleusercontent.com"
+	antigravityClientSecret        = "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"
+	defaultAntigravityAgent        = "antigravity/1.11.5 windows/amd64"
+	antigravityAuthType            = "antigravity"
+	refreshSkew                    = 3000 * time.Second
 )
 
 var randSource = rand.New(rand.NewSource(time.Now().UnixNano()))
@@ -1152,7 +1152,7 @@ func antigravityBaseURLFallbackOrder(auth *cliproxyauth.Auth) []string {
 	}
 	return []string{
 		antigravityBaseURLDaily,
-		// antigravityBaseURLAutopush,
+		antigravitySandboxBaseURLDaily,
 		antigravityBaseURLProd,
 	}
 }

internal/translator/antigravity/claude/antigravity_claude_request.go

@@ -86,6 +86,10 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 				hasSystemInstruction = true
 			}
 		}
+	} else if systemResult.Type == gjson.String {
+		systemInstructionJSON = `{"role":"user","parts":[{"text":""}]}`
+		systemInstructionJSON, _ = sjson.Set(systemInstructionJSON, "parts.0.text", systemResult.String())
+		hasSystemInstruction = true
 	}
 
 	// contents
@@ -121,32 +125,31 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 						// Use GetThinkingText to handle wrapped thinking objects
 						thinkingText := util.GetThinkingText(contentResult)
 						signatureResult := contentResult.Get("signature")
-					clientSignature := ""
-					if signatureResult.Exists() && signatureResult.String() != "" {
-						clientSignature = signatureResult.String()
-					}
-
-					// Always try cached signature first (more reliable than client-provided)
-					// Client may send stale or invalid signatures from different sessions
-					signature := ""
-					if sessionID != "" && thinkingText != "" {
-						if cachedSig := cache.GetCachedSignature(sessionID, thinkingText); cachedSig != "" {
-							signature = cachedSig
-							log.Debugf("Using cached signature for thinking block")
+						clientSignature := ""
+						if signatureResult.Exists() && signatureResult.String() != "" {
+							clientSignature = signatureResult.String()
 						}
-					}
 
-					// Fallback to client signature only if cache miss and client signature is valid
-					if signature == "" && cache.HasValidSignature(clientSignature) {
-						signature = clientSignature
-						log.Debugf("Using client-provided signature for thinking block")
-					}
+						// Always try cached signature first (more reliable than client-provided)
+						// Client may send stale or invalid signatures from different sessions
+						signature := ""
+						if sessionID != "" && thinkingText != "" {
+							if cachedSig := cache.GetCachedSignature(sessionID, thinkingText); cachedSig != "" {
+								signature = cachedSig
+								log.Debugf("Using cached signature for thinking block")
+							}
+						}
 
-					// Store for subsequent tool_use in the same message
-					if cache.HasValidSignature(signature) {
-						currentMessageThinkingSignature = signature
-					}
+						// Fallback to client signature only if cache miss and client signature is valid
+						if signature == "" && cache.HasValidSignature(clientSignature) {
+							signature = clientSignature
+							log.Debugf("Using client-provided signature for thinking block")
+						}
 
+						// Store for subsequent tool_use in the same message
+						if cache.HasValidSignature(signature) {
+							currentMessageThinkingSignature = signature
+						}
 
 						// Skip trailing unsigned thinking blocks on last assistant message
 						isUnsigned := !cache.HasValidSignature(signature)
@@ -321,6 +324,7 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 	// tools
 	toolsJSON := ""
 	toolDeclCount := 0
+	allowedToolKeys := []string{"name", "description", "behavior", "parameters", "parametersJsonSchema", "response", "responseJsonSchema"}
 	toolsResult := gjson.GetBytes(rawJSON, "tools")
 	if toolsResult.IsArray() {
 		toolsJSON = `[{"functionDeclarations":[]}]`
@@ -333,10 +337,12 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 				inputSchema := util.CleanJSONSchemaForAntigravity(inputSchemaResult.Raw)
 				tool, _ := sjson.Delete(toolResult.Raw, "input_schema")
 				tool, _ = sjson.SetRaw(tool, "parametersJsonSchema", inputSchema)
-				tool, _ = sjson.Delete(tool, "strict")
-				tool, _ = sjson.Delete(tool, "input_examples")
-				tool, _ = sjson.Delete(tool, "type")
-				tool, _ = sjson.Delete(tool, "cache_control")
+				for toolKey := range gjson.Parse(tool).Map() {
+					if util.InArray(allowedToolKeys, toolKey) {
+						continue
+					}
+					tool, _ = sjson.Delete(tool, toolKey)
+				}
 				toolsJSON, _ = sjson.SetRaw(toolsJSON, "0.functionDeclarations.-1", tool)
 				toolDeclCount++
 			}

internal/translator/antigravity/openai/chat-completions/antigravity_openai_request.go

@@ -192,6 +192,14 @@ func ConvertOpenAIRequestToAntigravity(modelName string, inputRawJSON []byte, _
 				} else if content.IsObject() && content.Get("type").String() == "text" {
 					out, _ = sjson.SetBytes(out, "request.systemInstruction.role", "user")
 					out, _ = sjson.SetBytes(out, "request.systemInstruction.parts.0.text", content.Get("text").String())
+				} else if content.IsArray() {
+					contents := content.Array()
+					if len(contents) > 0 {
+						out, _ = sjson.SetBytes(out, "request.systemInstruction.role", "user")
+						for j := 0; j < len(contents); j++ {
+							out, _ = sjson.SetBytes(out, fmt.Sprintf("request.systemInstruction.parts.%d.text", j), contents[j].Get("text").String())
+						}
+					}
 				}
 			} else if role == "user" || (role == "system" && len(arr) == 1) {
 				// Build single user content node to avoid splitting into multiple contents
@@ -258,7 +266,11 @@ func ConvertOpenAIRequestToAntigravity(modelName string, inputRawJSON []byte, _
 						fargs := tc.Get("function.arguments").String()
 						node, _ = sjson.SetBytes(node, "parts."+itoa(p)+".functionCall.id", fid)
 						node, _ = sjson.SetBytes(node, "parts."+itoa(p)+".functionCall.name", fname)
-						node, _ = sjson.SetRawBytes(node, "parts."+itoa(p)+".functionCall.args", []byte(fargs))
+						if gjson.Valid(fargs) {
+							node, _ = sjson.SetRawBytes(node, "parts."+itoa(p)+".functionCall.args", []byte(fargs))
+						} else {
+							node, _ = sjson.SetBytes(node, "parts."+itoa(p)+".functionCall.args.params", []byte(fargs))
+						}
 						node, _ = sjson.SetBytes(node, "parts."+itoa(p)+".thoughtSignature", geminiCLIFunctionThoughtSignature)
 						p++
 						if fid != "" {

internal/translator/gemini-cli/claude/gemini-cli_claude_request.go

@@ -62,6 +62,8 @@ func ConvertClaudeRequestToCLI(modelName string, inputRawJSON []byte, _ bool) []
 		if hasSystemParts {
 			out, _ = sjson.SetRaw(out, "request.systemInstruction", systemInstruction)
 		}
+	} else if systemResult.Type == gjson.String {
+		out, _ = sjson.Set(out, "request.systemInstruction.parts.-1.text", systemResult.String())
 	}
 
 	// contents

internal/translator/gemini-cli/openai/chat-completions/gemini-cli_openai_request.go

@@ -160,6 +160,14 @@ func ConvertOpenAIRequestToGeminiCLI(modelName string, inputRawJSON []byte, _ bo
 				} else if content.IsObject() && content.Get("type").String() == "text" {
 					out, _ = sjson.SetBytes(out, "request.systemInstruction.role", "user")
 					out, _ = sjson.SetBytes(out, "request.systemInstruction.parts.0.text", content.Get("text").String())
+				} else if content.IsArray() {
+					contents := content.Array()
+					if len(contents) > 0 {
+						out, _ = sjson.SetBytes(out, "request.systemInstruction.role", "user")
+						for j := 0; j < len(contents); j++ {
+							out, _ = sjson.SetBytes(out, fmt.Sprintf("request.systemInstruction.parts.%d.text", j), contents[j].Get("text").String())
+						}
+					}
 				}
 			} else if role == "user" || (role == "system" && len(arr) == 1) {
 				// Build single user content node to avoid splitting into multiple contents

internal/translator/gemini/claude/gemini_claude_request.go

@@ -55,6 +55,8 @@ func ConvertClaudeRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 		if hasSystemParts {
 			out, _ = sjson.SetRaw(out, "system_instruction", systemInstruction)
 		}
+	} else if systemResult.Type == gjson.String {
+		out, _ = sjson.Set(out, "request.system_instruction.parts.-1.text", systemResult.String())
 	}
 
 	// contents

internal/translator/gemini/openai/chat-completions/gemini_openai_request.go

@@ -178,6 +178,14 @@ func ConvertOpenAIRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 				} else if content.IsObject() && content.Get("type").String() == "text" {
 					out, _ = sjson.SetBytes(out, "system_instruction.role", "user")
 					out, _ = sjson.SetBytes(out, "system_instruction.parts.0.text", content.Get("text").String())
+				} else if content.IsArray() {
+					contents := content.Array()
+					if len(contents) > 0 {
+						out, _ = sjson.SetBytes(out, "request.systemInstruction.role", "user")
+						for j := 0; j < len(contents); j++ {
+							out, _ = sjson.SetBytes(out, fmt.Sprintf("request.systemInstruction.parts.%d.text", j), contents[j].Get("text").String())
+						}
+					}
 				}
 			} else if role == "user" || (role == "system" && len(arr) == 1) {
 				// Build single user content node to avoid splitting into multiple contents