fix(antigravity): resolve empty functionResponse.name for toolu_* tool_use_id format

The Claude-to-Gemini translator derived function names by splitting
tool_use_id on "-", which produced empty strings for IDs with exactly
2 segments (e.g. toolu_tool-<uuid>). Replace the string-splitting
heuristic with a lookup map built from tool_use blocks during the
main processing loop, with fallback to the raw ID on miss.

internal/translator/antigravity/claude/antigravity_claude_request.go

@@ -12,6 +12,7 @@ import (
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/thinking"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/translator/gemini/common"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
+	log "github.com/sirupsen/logrus"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 )
@@ -68,6 +69,10 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 	contentsJSON := "[]"
 	hasContents := false
 
+	// tool_use_id → tool_name lookup, populated incrementally during the main loop.
+	// Claude's tool_result references tool_use by ID; Gemini requires functionResponse.name.
+	toolNameByID := make(map[string]string)
+
 	messagesResult := gjson.GetBytes(rawJSON, "messages")
 	if messagesResult.IsArray() {
 		messageResults := messagesResult.Array()
@@ -170,6 +175,10 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 						argsResult := contentResult.Get("input")
 						functionID := contentResult.Get("id").String()
 
+						if functionID != "" && functionName != "" {
+							toolNameByID[functionID] = functionName
+						}
+
 						// Handle both object and string input formats
 						var argsRaw string
 						if argsResult.IsObject() {
@@ -206,10 +215,19 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 					} else if contentTypeResult.Type == gjson.String && contentTypeResult.String() == "tool_result" {
 						toolCallID := contentResult.Get("tool_use_id").String()
 						if toolCallID != "" {
-							funcName := toolCallID
+							funcName, ok := toolNameByID[toolCallID]
-							toolCallIDs := strings.Split(toolCallID, "-")
+							if !ok {
-							if len(toolCallIDs) > 1 {
+								// Fallback: derive a semantic name from the ID by stripping
-								funcName = strings.Join(toolCallIDs[0:len(toolCallIDs)-2], "-")
+								// the last two dash-separated segments (e.g. "get_weather-call-123" → "get_weather").
+								// Only use the raw ID as a last resort when the heuristic produces an empty string.
+								parts := strings.Split(toolCallID, "-")
+								if len(parts) > 2 {
+									funcName = strings.Join(parts[:len(parts)-2], "-")
+								}
+								if funcName == "" {
+									funcName = toolCallID
+								}
+								log.Warnf("antigravity claude request: tool_result references unknown tool_use_id=%s, derived function name=%s", toolCallID, funcName)
 							}
 							functionResponseResult := contentResult.Get("content")
 

internal/translator/antigravity/claude/antigravity_claude_request_test.go

@@ -365,6 +365,17 @@ func TestConvertClaudeRequestToAntigravity_ToolResult(t *testing.T) {
 	inputJSON := []byte(`{
 		"model": "claude-3-5-sonnet-20240620",
 		"messages": [
+			{
+				"role": "assistant",
+				"content": [
+					{
+						"type": "tool_use",
+						"id": "get_weather-call-123",
+						"name": "get_weather",
+						"input": {"location": "Paris"}
+					}
+				]
+			},
 			{
 				"role": "user",
 				"content": [
@@ -382,13 +393,177 @@ func TestConvertClaudeRequestToAntigravity_ToolResult(t *testing.T) {
 	outputStr := string(output)
 
 	// Check function response conversion
-	funcResp := gjson.Get(outputStr, "request.contents.0.parts.0.functionResponse")
+	funcResp := gjson.Get(outputStr, "request.contents.1.parts.0.functionResponse")
 	if !funcResp.Exists() {
 		t.Error("functionResponse should exist")
 	}
 	if funcResp.Get("id").String() != "get_weather-call-123" {
 		t.Errorf("Expected function id, got '%s'", funcResp.Get("id").String())
 	}
+	if funcResp.Get("name").String() != "get_weather" {
+		t.Errorf("Expected function name 'get_weather', got '%s'", funcResp.Get("name").String())
+	}
+}
+
+func TestConvertClaudeRequestToAntigravity_ToolResultName_TouluFormat(t *testing.T) {
+	inputJSON := []byte(`{
+		"model": "claude-haiku-4-5-20251001",
+		"messages": [
+			{
+				"role": "assistant",
+				"content": [
+					{
+						"type": "tool_use",
+						"id": "toolu_tool-48fca351f12844eabf49dad8b63886d2",
+						"name": "Glob",
+						"input": {"pattern": "**/*.py"}
+					},
+					{
+						"type": "tool_use",
+						"id": "toolu_tool-cf2d061f75f845c49aacc18ee75ee708",
+						"name": "Bash",
+						"input": {"command": "ls"}
+					}
+				]
+			},
+			{
+				"role": "user",
+				"content": [
+					{
+						"type": "tool_result",
+						"tool_use_id": "toolu_tool-48fca351f12844eabf49dad8b63886d2",
+						"content": "file1.py\nfile2.py"
+					},
+					{
+						"type": "tool_result",
+						"tool_use_id": "toolu_tool-cf2d061f75f845c49aacc18ee75ee708",
+						"content": "total 10"
+					}
+				]
+			}
+		]
+	}`)
+
+	output := ConvertClaudeRequestToAntigravity("claude-haiku-4-5-20251001", inputJSON, false)
+	outputStr := string(output)
+
+	funcResp0 := gjson.Get(outputStr, "request.contents.1.parts.0.functionResponse")
+	if !funcResp0.Exists() {
+		t.Fatal("first functionResponse should exist")
+	}
+	if got := funcResp0.Get("name").String(); got != "Glob" {
+		t.Errorf("Expected name 'Glob' for toolu_ format, got '%s'", got)
+	}
+
+	funcResp1 := gjson.Get(outputStr, "request.contents.1.parts.1.functionResponse")
+	if !funcResp1.Exists() {
+		t.Fatal("second functionResponse should exist")
+	}
+	if got := funcResp1.Get("name").String(); got != "Bash" {
+		t.Errorf("Expected name 'Bash' for toolu_ format, got '%s'", got)
+	}
+}
+
+func TestConvertClaudeRequestToAntigravity_ToolResultName_CustomFormat(t *testing.T) {
+	inputJSON := []byte(`{
+		"model": "claude-haiku-4-5-20251001",
+		"messages": [
+			{
+				"role": "assistant",
+				"content": [
+					{
+						"type": "tool_use",
+						"id": "Read-1773420180464065165-1327",
+						"name": "Read",
+						"input": {"file_path": "/tmp/test.py"}
+					}
+				]
+			},
+			{
+				"role": "user",
+				"content": [
+					{
+						"type": "tool_result",
+						"tool_use_id": "Read-1773420180464065165-1327",
+						"content": "file content here"
+					}
+				]
+			}
+		]
+	}`)
+
+	output := ConvertClaudeRequestToAntigravity("claude-haiku-4-5-20251001", inputJSON, false)
+	outputStr := string(output)
+
+	funcResp := gjson.Get(outputStr, "request.contents.1.parts.0.functionResponse")
+	if !funcResp.Exists() {
+		t.Fatal("functionResponse should exist")
+	}
+	if got := funcResp.Get("name").String(); got != "Read" {
+		t.Errorf("Expected name 'Read', got '%s'", got)
+	}
+}
+
+func TestConvertClaudeRequestToAntigravity_ToolResultName_NoMatchingToolUse_Heuristic(t *testing.T) {
+	inputJSON := []byte(`{
+		"model": "claude-sonnet-4-5",
+		"messages": [
+			{
+				"role": "user",
+				"content": [
+					{
+						"type": "tool_result",
+						"tool_use_id": "get_weather-call-123",
+						"content": "22C sunny"
+					}
+				]
+			}
+		]
+	}`)
+
+	output := ConvertClaudeRequestToAntigravity("claude-sonnet-4-5", inputJSON, false)
+	outputStr := string(output)
+
+	funcResp := gjson.Get(outputStr, "request.contents.0.parts.0.functionResponse")
+	if !funcResp.Exists() {
+		t.Fatal("functionResponse should exist")
+	}
+	if got := funcResp.Get("name").String(); got != "get_weather" {
+		t.Errorf("Expected heuristic-derived name 'get_weather', got '%s'", got)
+	}
+}
+
+func TestConvertClaudeRequestToAntigravity_ToolResultName_NoMatchingToolUse_RawID(t *testing.T) {
+	inputJSON := []byte(`{
+		"model": "claude-sonnet-4-5",
+		"messages": [
+			{
+				"role": "user",
+				"content": [
+					{
+						"type": "tool_result",
+						"tool_use_id": "toolu_tool-48fca351f12844eabf49dad8b63886d2",
+						"content": "result data"
+					}
+				]
+			}
+		]
+	}`)
+
+	output := ConvertClaudeRequestToAntigravity("claude-sonnet-4-5", inputJSON, false)
+	outputStr := string(output)
+
+	funcResp := gjson.Get(outputStr, "request.contents.0.parts.0.functionResponse")
+	if !funcResp.Exists() {
+		t.Fatal("functionResponse should exist")
+	}
+	got := funcResp.Get("name").String()
+	if got == "" {
+		t.Error("functionResponse.name must not be empty")
+	}
+	if got != "toolu_tool-48fca351f12844eabf49dad8b63886d2" {
+		t.Errorf("Expected raw ID as last-resort name, got '%s'", got)
+	}
 }
 
 func TestConvertClaudeRequestToAntigravity_ThinkingConfig(t *testing.T) {