fix: correct token counting

Author: lich0821

internal/proxy/streaming.go

@@ -18,8 +18,11 @@ import (
 
 // handleStreamingResponse processes streaming SSE responses
 func (p *Proxy) handleStreamingResponse(w http.ResponseWriter, resp *http.Response, endpoint config.Endpoint, trans transformer.Transformer, transformerName string, thinkingEnabled bool) (int, int, error) {
-	// Copy response headers
+	// Copy response headers except Content-Length (streaming response length is unknown)
 	for key, values := range resp.Header {
+		if key == "Content-Length" {
+			continue
+		}
 		for _, value := range values {
 			w.Header().Add(key, value)
 		}
@@ -88,7 +91,7 @@ func (p *Proxy) handleStreamingResponse(w http.ResponseWriter, resp *http.Respon
 			} else {
 				logger.DebugLog("[%s] SSE Event #%d (Transformed): %s", endpoint.Name, eventCount, string(transformedEvent))
 
-				p.extractTokensFromEvent(eventData, &inputTokens, &outputTokens)
+				p.extractTokensFromEvent(transformedEvent, &inputTokens, &outputTokens)
 				p.extractTextFromEvent(transformedEvent, &outputText)
 
 				if _, writeErr := w.Write(transformedEvent); writeErr != nil {
@@ -127,11 +130,11 @@ func (p *Proxy) extractTokensFromEvent(eventData []byte, inputTokens, outputToke
 	scanner := bufio.NewScanner(bytes.NewReader(eventData))
 	for scanner.Scan() {
 		line := scanner.Text()
-		if !strings.HasPrefix(line, "data: ") {
+		if !strings.HasPrefix(line, "data:") {
 			continue
 		}
 
-		jsonData := strings.TrimPrefix(line, "data: ")
+		jsonData := strings.TrimPrefix(line, "data:")
 		var event map[string]interface{}
 		if err := json.Unmarshal([]byte(jsonData), &event); err != nil {
 			continue
@@ -161,11 +164,11 @@ func (p *Proxy) extractTextFromEvent(transformedEvent []byte, outputText *string
 	scanner := bufio.NewScanner(bytes.NewReader(transformedEvent))
 	for scanner.Scan() {
 		line := scanner.Text()
-		if !strings.HasPrefix(line, "data: ") {
+		if !strings.HasPrefix(line, "data:") {
 			continue
 		}
 
-		jsonData := strings.TrimPrefix(line, "data: ")
+		jsonData := strings.TrimPrefix(line, "data:")
 		var event map[string]interface{}
 		if err := json.Unmarshal([]byte(jsonData), &event); err != nil {
 			continue