Fixed: #1741

fix(translator): handle tool name mappings and improve tool call handling in OpenAI and Claude integrations

internal/translator/gemini/claude/gemini_claude_request.go

@@ -85,6 +85,11 @@ func ConvertClaudeRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 
 					case "tool_use":
 						functionName := contentResult.Get("name").String()
+						if toolUseID := contentResult.Get("id").String(); toolUseID != "" {
+							if derived := toolNameFromClaudeToolUseID(toolUseID); derived != "" {
+								functionName = derived
+							}
+						}
 						functionArgs := contentResult.Get("input").String()
 						argsResult := gjson.Parse(functionArgs)
 						if argsResult.IsObject() && gjson.Valid(functionArgs) {
@@ -100,10 +105,9 @@ func ConvertClaudeRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 						if toolCallID == "" {
 							return true
 						}
-						funcName := toolCallID
+						funcName := toolNameFromClaudeToolUseID(toolCallID)
-						toolCallIDs := strings.Split(toolCallID, "-")
+						if funcName == "" {
-						if len(toolCallIDs) > 1 {
+							funcName = toolCallID
-							funcName = strings.Join(toolCallIDs[0:len(toolCallIDs)-1], "-")
 						}
 						responseData := contentResult.Get("content").Raw
 						part := `{"functionResponse":{"name":"","response":{"result":""}}}`
@@ -230,3 +234,11 @@ func ConvertClaudeRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 
 	return result
 }
+
+func toolNameFromClaudeToolUseID(toolUseID string) string {
+	parts := strings.Split(toolUseID, "-")
+	if len(parts) <= 1 {
+		return ""
+	}
+	return strings.Join(parts[0:len(parts)-1], "-")
+}

internal/translator/gemini/claude/gemini_claude_response.go

@@ -12,8 +12,8 @@ import (
 	"fmt"
 	"strings"
 	"sync/atomic"
-	"time"
 
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
 )
@@ -25,6 +25,8 @@ type Params struct {
 	ResponseType     int
 	ResponseIndex    int
 	HasContent       bool // Tracks whether any content (text, thinking, or tool use) has been output
+	ToolNameMap      map[string]string
+	SawToolCall      bool
 }
 
 // toolUseIDCounter provides a process-wide unique counter for tool use identifiers.
@@ -53,6 +55,8 @@ func ConvertGeminiResponseToClaude(_ context.Context, _ string, originalRequestR
 			HasFirstResponse: false,
 			ResponseType:     0,
 			ResponseIndex:    0,
+			ToolNameMap:      util.ToolNameMapFromClaudeRequest(originalRequestRawJSON),
+			SawToolCall:      false,
 		}
 	}
 
@@ -66,8 +70,6 @@ func ConvertGeminiResponseToClaude(_ context.Context, _ string, originalRequestR
 		return []string{}
 	}
 
-	// Track whether tools are being used in this response chunk
-	usedTool := false
 	output := ""
 
 	// Initialize the streaming session with a message_start event
@@ -175,12 +177,13 @@ func ConvertGeminiResponseToClaude(_ context.Context, _ string, originalRequestR
 			} else if functionCallResult.Exists() {
 				// Handle function/tool calls from the AI model
 				// This processes tool usage requests and formats them for Claude API compatibility
-				usedTool = true
+				(*param).(*Params).SawToolCall = true
-				fcName := functionCallResult.Get("name").String()
+				upstreamToolName := functionCallResult.Get("name").String()
+				clientToolName := util.MapToolName((*param).(*Params).ToolNameMap, upstreamToolName)
 
 				// FIX: Handle streaming split/delta where name might be empty in subsequent chunks.
 				// If we are already in tool use mode and name is empty, treat as continuation (delta).
-				if (*param).(*Params).ResponseType == 3 && fcName == "" {
+				if (*param).(*Params).ResponseType == 3 && upstreamToolName == "" {
 					if fcArgsResult := functionCallResult.Get("args"); fcArgsResult.Exists() {
 						output = output + "event: content_block_delta\n"
 						data, _ := sjson.Set(fmt.Sprintf(`{"type":"content_block_delta","index":%d,"delta":{"type":"input_json_delta","partial_json":""}}`, (*param).(*Params).ResponseIndex), "delta.partial_json", fcArgsResult.Raw)
@@ -221,8 +224,8 @@ func ConvertGeminiResponseToClaude(_ context.Context, _ string, originalRequestR
 
 				// Create the tool use block with unique ID and function details
 				data := fmt.Sprintf(`{"type":"content_block_start","index":%d,"content_block":{"type":"tool_use","id":"","name":"","input":{}}}`, (*param).(*Params).ResponseIndex)
-				data, _ = sjson.Set(data, "content_block.id", fmt.Sprintf("%s-%d-%d", fcName, time.Now().UnixNano(), atomic.AddUint64(&toolUseIDCounter, 1)))
+				data, _ = sjson.Set(data, "content_block.id", fmt.Sprintf("%s-%d", upstreamToolName, atomic.AddUint64(&toolUseIDCounter, 1)))
-				data, _ = sjson.Set(data, "content_block.name", fcName)
+				data, _ = sjson.Set(data, "content_block.name", clientToolName)
 				output = output + fmt.Sprintf("data: %s\n\n\n", data)
 
 				if fcArgsResult := functionCallResult.Get("args"); fcArgsResult.Exists() {
@@ -249,7 +252,7 @@ func ConvertGeminiResponseToClaude(_ context.Context, _ string, originalRequestR
 				output = output + `data: `
 
 				template := `{"type":"message_delta","delta":{"stop_reason":"end_turn","stop_sequence":null},"usage":{"input_tokens":0,"output_tokens":0}}`
-				if usedTool {
+				if (*param).(*Params).SawToolCall {
 					template = `{"type":"message_delta","delta":{"stop_reason":"tool_use","stop_sequence":null},"usage":{"input_tokens":0,"output_tokens":0}}`
 				} else if finish := gjson.GetBytes(rawJSON, "candidates.0.finishReason"); finish.Exists() && finish.String() == "MAX_TOKENS" {
 					template = `{"type":"message_delta","delta":{"stop_reason":"max_tokens","stop_sequence":null},"usage":{"input_tokens":0,"output_tokens":0}}`
@@ -278,10 +281,10 @@ func ConvertGeminiResponseToClaude(_ context.Context, _ string, originalRequestR
 // Returns:
 //   - string: A Claude-compatible JSON response.
 func ConvertGeminiResponseToClaudeNonStream(_ context.Context, _ string, originalRequestRawJSON, requestRawJSON, rawJSON []byte, _ *any) string {
-	_ = originalRequestRawJSON
 	_ = requestRawJSON
 
 	root := gjson.ParseBytes(rawJSON)
+	toolNameMap := util.ToolNameMapFromClaudeRequest(originalRequestRawJSON)
 
 	out := `{"id":"","type":"message","role":"assistant","model":"","content":[],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":0,"output_tokens":0}}`
 	out, _ = sjson.Set(out, "id", root.Get("responseId").String())
@@ -336,11 +339,12 @@ func ConvertGeminiResponseToClaudeNonStream(_ context.Context, _ string, origina
 				flushText()
 				hasToolCall = true
 
-				name := functionCall.Get("name").String()
+				upstreamToolName := functionCall.Get("name").String()
+				clientToolName := util.MapToolName(toolNameMap, upstreamToolName)
 				toolIDCounter++
 				toolBlock := `{"type":"tool_use","id":"","name":"","input":{}}`
-				toolBlock, _ = sjson.Set(toolBlock, "id", fmt.Sprintf("tool_%d", toolIDCounter))
+				toolBlock, _ = sjson.Set(toolBlock, "id", fmt.Sprintf("%s-%d", upstreamToolName, toolIDCounter))
-				toolBlock, _ = sjson.Set(toolBlock, "name", name)
+				toolBlock, _ = sjson.Set(toolBlock, "name", clientToolName)
 				inputRaw := "{}"
 				if args := functionCall.Get("args"); args.Exists() && gjson.Valid(args.Raw) && args.IsObject() {
 					inputRaw = args.Raw

internal/translator/openai/claude/openai_claude_response.go

@@ -22,9 +22,11 @@ var (
 
 // ConvertOpenAIResponseToAnthropicParams holds parameters for response conversion
 type ConvertOpenAIResponseToAnthropicParams struct {
-	MessageID string
+	MessageID   string
-	Model     string
+	Model       string
-	CreatedAt int64
+	CreatedAt   int64
+	ToolNameMap map[string]string
+	SawToolCall bool
 	// Content accumulator for streaming
 	ContentAccumulator strings.Builder
 	// Tool calls accumulator for streaming
@@ -78,6 +80,8 @@ func ConvertOpenAIResponseToClaude(_ context.Context, _ string, originalRequestR
 			MessageID:                   "",
 			Model:                       "",
 			CreatedAt:                   0,
+			ToolNameMap:                 nil,
+			SawToolCall:                 false,
 			ContentAccumulator:          strings.Builder{},
 			ToolCallsAccumulator:        nil,
 			TextContentBlockStarted:     false,
@@ -97,6 +101,10 @@ func ConvertOpenAIResponseToClaude(_ context.Context, _ string, originalRequestR
 	}
 	rawJSON = bytes.TrimSpace(rawJSON[5:])
 
+	if (*param).(*ConvertOpenAIResponseToAnthropicParams).ToolNameMap == nil {
+		(*param).(*ConvertOpenAIResponseToAnthropicParams).ToolNameMap = util.ToolNameMapFromClaudeRequest(originalRequestRawJSON)
+	}
+
 	// Check if this is the [DONE] marker
 	rawStr := strings.TrimSpace(string(rawJSON))
 	if rawStr == "[DONE]" {
@@ -111,6 +119,16 @@ func ConvertOpenAIResponseToClaude(_ context.Context, _ string, originalRequestR
 	}
 }
 
+func effectiveOpenAIFinishReason(param *ConvertOpenAIResponseToAnthropicParams) string {
+	if param == nil {
+		return ""
+	}
+	if param.SawToolCall {
+		return "tool_calls"
+	}
+	return param.FinishReason
+}
+
 // convertOpenAIStreamingChunkToAnthropic converts OpenAI streaming chunk to Anthropic streaming events
 func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAIResponseToAnthropicParams) []string {
 	root := gjson.ParseBytes(rawJSON)
@@ -197,6 +215,7 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 			}
 
 			toolCalls.ForEach(func(_, toolCall gjson.Result) bool {
+				param.SawToolCall = true
 				index := int(toolCall.Get("index").Int())
 				blockIndex := param.toolContentBlockIndex(index)
 
@@ -215,7 +234,7 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 				// Handle function name
 				if function := toolCall.Get("function"); function.Exists() {
 					if name := function.Get("name"); name.Exists() {
-						accumulator.Name = name.String()
+						accumulator.Name = util.MapToolName(param.ToolNameMap, name.String())
 
 						stopThinkingContentBlock(param, &results)
 
@@ -246,7 +265,11 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 	// Handle finish_reason (but don't send message_delta/message_stop yet)
 	if finishReason := root.Get("choices.0.finish_reason"); finishReason.Exists() && finishReason.String() != "" {
 		reason := finishReason.String()
-		param.FinishReason = reason
+		if param.SawToolCall {
+			param.FinishReason = "tool_calls"
+		} else {
+			param.FinishReason = reason
+		}
 
 		// Send content_block_stop for thinking content if needed
 		if param.ThinkingContentBlockStarted {
@@ -294,7 +317,7 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 			inputTokens, outputTokens, cachedTokens = extractOpenAIUsage(usage)
 			// Send message_delta with usage
 			messageDeltaJSON := `{"type":"message_delta","delta":{"stop_reason":"","stop_sequence":null},"usage":{"input_tokens":0,"output_tokens":0}}`
-			messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "delta.stop_reason", mapOpenAIFinishReasonToAnthropic(param.FinishReason))
+			messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "delta.stop_reason", mapOpenAIFinishReasonToAnthropic(effectiveOpenAIFinishReason(param)))
 			messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "usage.input_tokens", inputTokens)
 			messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "usage.output_tokens", outputTokens)
 			if cachedTokens > 0 {
@@ -348,7 +371,7 @@ func convertOpenAIDoneToAnthropic(param *ConvertOpenAIResponseToAnthropicParams)
 	// If we haven't sent message_delta yet (no usage info was received), send it now
 	if param.FinishReason != "" && !param.MessageDeltaSent {
 		messageDeltaJSON := `{"type":"message_delta","delta":{"stop_reason":"","stop_sequence":null},"usage":{"input_tokens":0,"output_tokens":0}}`
-		messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "delta.stop_reason", mapOpenAIFinishReasonToAnthropic(param.FinishReason))
+		messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "delta.stop_reason", mapOpenAIFinishReasonToAnthropic(effectiveOpenAIFinishReason(param)))
 		results = append(results, "event: message_delta\ndata: "+messageDeltaJSON+"\n\n")
 		param.MessageDeltaSent = true
 	}
@@ -531,10 +554,10 @@ func stopTextContentBlock(param *ConvertOpenAIResponseToAnthropicParams, results
 // Returns:
 //   - string: An Anthropic-compatible JSON response.
 func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, originalRequestRawJSON, requestRawJSON, rawJSON []byte, _ *any) string {
-	_ = originalRequestRawJSON
 	_ = requestRawJSON
 
 	root := gjson.ParseBytes(rawJSON)
+	toolNameMap := util.ToolNameMapFromClaudeRequest(originalRequestRawJSON)
 	out := `{"id":"","type":"message","role":"assistant","model":"","content":[],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":0,"output_tokens":0}}`
 	out, _ = sjson.Set(out, "id", root.Get("id").String())
 	out, _ = sjson.Set(out, "model", root.Get("model").String())
@@ -590,7 +613,7 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 									hasToolCall = true
 									toolUse := `{"type":"tool_use","id":"","name":"","input":{}}`
 									toolUse, _ = sjson.Set(toolUse, "id", tc.Get("id").String())
-									toolUse, _ = sjson.Set(toolUse, "name", tc.Get("function.name").String())
+									toolUse, _ = sjson.Set(toolUse, "name", util.MapToolName(toolNameMap, tc.Get("function.name").String()))
 
 									argsStr := util.FixJSON(tc.Get("function.arguments").String())
 									if argsStr != "" && gjson.Valid(argsStr) {
@@ -647,7 +670,7 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 					hasToolCall = true
 					toolUseBlock := `{"type":"tool_use","id":"","name":"","input":{}}`
 					toolUseBlock, _ = sjson.Set(toolUseBlock, "id", toolCall.Get("id").String())
-					toolUseBlock, _ = sjson.Set(toolUseBlock, "name", toolCall.Get("function.name").String())
+					toolUseBlock, _ = sjson.Set(toolUseBlock, "name", util.MapToolName(toolNameMap, toolCall.Get("function.name").String()))
 
 					argsStr := util.FixJSON(toolCall.Get("function.arguments").String())
 					if argsStr != "" && gjson.Valid(argsStr) {

internal/util/translator.go

@@ -6,6 +6,7 @@ package util
 import (
 	"bytes"
 	"fmt"
+	"strings"
 
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
@@ -219,3 +220,54 @@ func FixJSON(input string) string {
 
 	return out.String()
 }
+
+func CanonicalToolName(name string) string {
+	canonical := strings.TrimSpace(name)
+	canonical = strings.TrimLeft(canonical, "_")
+	return strings.ToLower(canonical)
+}
+
+// ToolNameMapFromClaudeRequest returns a canonical-name -> original-name map extracted from a Claude request.
+// It is used to restore exact tool name casing for clients that require strict tool name matching (e.g. Claude Code).
+func ToolNameMapFromClaudeRequest(rawJSON []byte) map[string]string {
+	if len(rawJSON) == 0 || !gjson.ValidBytes(rawJSON) {
+		return nil
+	}
+
+	tools := gjson.GetBytes(rawJSON, "tools")
+	if !tools.Exists() || !tools.IsArray() {
+		return nil
+	}
+
+	toolResults := tools.Array()
+	out := make(map[string]string, len(toolResults))
+	tools.ForEach(func(_, tool gjson.Result) bool {
+		name := strings.TrimSpace(tool.Get("name").String())
+		if name == "" {
+			return true
+		}
+		key := CanonicalToolName(name)
+		if key == "" {
+			return true
+		}
+		if _, exists := out[key]; !exists {
+			out[key] = name
+		}
+		return true
+	})
+
+	if len(out) == 0 {
+		return nil
+	}
+	return out
+}
+
+func MapToolName(toolNameMap map[string]string, name string) string {
+	if name == "" || toolNameMap == nil {
+		return name
+	}
+	if mapped, ok := toolNameMap[CanonicalToolName(name)]; ok && mapped != "" {
+		return mapped
+	}
+	return name
+}