diff --git a/handler.go b/handler.go
index e87b04a..f211f54 100644
--- a/handler.go
+++ b/handler.go
@@ -140,6 +140,7 @@ func handleChatCompletions(w http.ResponseWriter, r *http.Request) {
 
 		for scanner.Scan() {
 			line := scanner.Text()
+			log.Printf("[stream] raw: %q", line)
 			if !strings.HasPrefix(line, "data: ") {
 				continue
 			}
@@ -152,8 +153,10 @@ func handleChatCompletions(w http.ResponseWriter, r *http.Request) {
 				Type string `json:"type"`
 			}
 			if err := json.Unmarshal([]byte(dataStr), &event); err != nil {
+				log.Printf("[stream] JSON err: %v", err)
 				continue
 			}
+			log.Printf("[stream] type=%s", event.Type)
 
 			openAIData := processAnthropicEvent(dataStr, chunkID, req.Model, created)
 			if openAIData != "" {
@@ -176,6 +179,7 @@ func handleChatCompletions(w http.ResponseWriter, r *http.Request) {
 
 		for scanner.Scan() {
 			line := scanner.Text()
+			log.Printf("[accumulate] raw: %q", line)
 			if !strings.HasPrefix(line, "data: ") {
 				continue
 			}
@@ -188,8 +192,10 @@ func handleChatCompletions(w http.ResponseWriter, r *http.Request) {
 				Type string `json:"type"`
 			}
 			if err := json.Unmarshal([]byte(dataStr), &event); err != nil {
+				log.Printf("[accumulate] JSON err: %v", err)
 				continue
 			}
+			log.Printf("[accumulate] type=%s data=%.200s", event.Type, dataStr)
 
 			switch event.Type {
 			case "message_start":