fix: claude stream tool call index save to state

core/relay/adaptor/anthropic/main.go

@@ -242,6 +242,8 @@ func StreamHandler(
 		writed bool
 	)
 
+	streamState := NewStreamState()
+
 	for scanner.Scan() {
 		data := scanner.Bytes()
 		if !render.IsValidSSEData(data) {
@@ -253,7 +255,7 @@ func StreamHandler(
 			break
 		}
 
-		response, err := StreamResponse2OpenAI(m, data)
+		response, err := streamState.StreamResponse2OpenAI(m, data)
 		if err != nil {
 			if writed {
 				log.Errorf("response error: %+v", err)

core/relay/adaptor/anthropic/openai.go

@@ -303,8 +303,42 @@ func batchPatchImage2Base64(ctx context.Context, imageTasks []*relaymodel.Claude
 	return nil
 }
 
-// https://docs.anthropic.com/claude/reference/messages-streaming
-func StreamResponse2OpenAI(
+// StreamState maintains state during streaming response conversion
+type StreamState struct {
+	// claudeIndexToToolCallIndex maps Claude's content block index to OpenAI tool call index
+	// Claude's index includes all content blocks (text, thinking, tool_use), but OpenAI only counts tool calls
+	claudeIndexToToolCallIndex map[int]int
+	// nextToolCallIndex tracks the next tool call index to assign (0-based)
+	nextToolCallIndex int
+}
+
+func NewStreamState() *StreamState {
+	return &StreamState{
+		claudeIndexToToolCallIndex: make(map[int]int),
+		nextToolCallIndex:          0,
+	}
+}
+
+// getToolCallIndex returns the OpenAI tool call index for a given Claude content block index
+// If this is the first time seeing this Claude index for a tool call, assigns a new tool call index
+func (s *StreamState) getToolCallIndex(claudeIndex int, isNewToolCall bool) int {
+	if idx, exists := s.claudeIndexToToolCallIndex[claudeIndex]; exists {
+		return idx
+	}
+
+	if isNewToolCall {
+		toolCallIndex := s.nextToolCallIndex
+		s.claudeIndexToToolCallIndex[claudeIndex] = toolCallIndex
+		s.nextToolCallIndex++
+		return toolCallIndex
+	}
+
+	// This shouldn't happen in normal flow, but return a safe default
+	return 0
+}
+
+// StreamResponse2OpenAI converts Claude streaming response to OpenAI format
+func (s *StreamState) StreamResponse2OpenAI(
 	meta *meta.Meta,
 	respData []byte,
 ) (*relaymodel.ChatCompletionsStreamResponse, adaptor.Error) {
@@ -340,8 +374,9 @@ func StreamResponse2OpenAI(
 		if claudeResponse.ContentBlock != nil {
 			content = claudeResponse.ContentBlock.Text
 			if claudeResponse.ContentBlock.Type == toolUseType {
+				toolCallIndex := s.getToolCallIndex(claudeResponse.Index, true)
 				tools = append(tools, relaymodel.ToolCall{
-					Index: claudeResponse.Index,
+					Index: toolCallIndex,
 					ID:    claudeResponse.ContentBlock.ID,
 					Type:  "function",
 					Function: relaymodel.Function{
@@ -354,8 +389,9 @@ func StreamResponse2OpenAI(
 		if claudeResponse.Delta != nil {
 			switch claudeResponse.Delta.Type {
 			case "input_json_delta":
+				toolCallIndex := s.getToolCallIndex(claudeResponse.Index, false)
 				tools = append(tools, relaymodel.ToolCall{
-					Index: claudeResponse.Index,
+					Index: toolCallIndex,
 					Type:  "function",
 					Function: relaymodel.Function{
 						Arguments: claudeResponse.Delta.PartialJSON,
@@ -514,6 +550,8 @@ func OpenAIStreamHandler(
 		writed bool
 	)
 
+	streamState := NewStreamState()
+
 	for scanner.Scan() {
 		data := scanner.Bytes()
 		if !render.IsValidSSEData(data) {
@@ -525,7 +563,7 @@ func OpenAIStreamHandler(
 			break
 		}
 
-		response, err := StreamResponse2OpenAI(m, data)
+		response, err := streamState.StreamResponse2OpenAI(m, data)
 		if err != nil {
 			if writed {
 				log.Errorf("response error: %+v", err)

core/relay/adaptor/aws/claude/claude.go

@@ -79,14 +79,16 @@ func StreamHandler(meta *meta.Meta, c *gin.Context) (model.Usage, adaptor.Error)
 		writed bool
 	)
 
+	streamState := anthropic.NewStreamState()
+
 	log := common.GetLogger(c)
 
 	for event := range stream.Events() {
 		switch v := event.(type) {
 		case *types.ResponseStreamMemberChunk:
 			data := v.Value.Bytes
 
-			response, err := anthropic.StreamResponse2OpenAI(meta, v.Value.Bytes)
+			response, err := streamState.StreamResponse2OpenAI(meta, v.Value.Bytes)
 			if err != nil {
 				if writed {
 					log.Errorf("response error: %+v", err)

core/relay/adaptor/aws/claude/openai.go

@@ -90,12 +90,14 @@ func OpenaiStreamHandler(meta *meta.Meta, c *gin.Context) (model.Usage, adaptor.
 		writed bool
 	)
 
+	streamState := anthropic.NewStreamState()
+
 	log := common.GetLogger(c)
 
 	for event := range stream.Events() {
 		switch v := event.(type) {
 		case *types.ResponseStreamMemberChunk:
-			response, err := anthropic.StreamResponse2OpenAI(meta, v.Value.Bytes)
+			response, err := streamState.StreamResponse2OpenAI(meta, v.Value.Bytes)
 			if err != nil {
 				if writed {
 					log.Errorf("response error: %+v", err)