Update app.py

app.py

@@ -3,6 +3,7 @@ from fastapi.responses import StreamingResponse
 from piper import PiperVoice
 import io
 import os
+import wave
 from pydantic import BaseModel
 
 app = FastAPI()
@@ -84,7 +85,15 @@ async def tts_post(request: TTSRequest):
         # 3. Load and Synthesize
         voice = get_voice(model_name)
         wav_buffer = io.BytesIO()
-        voice.synthesize(request.text, wav_buffer)
+        with wave.open(wav_buffer, "wb") as wav_file:
+            # Piper yields raw PCM; you must set these params manually
+            wav_file.setnchannels(1)  # Mono
+            wav_file.setsampwidth(2)  # 16-bit
+            wav_file.setframerate(voice.config.sample_rate)
+            
+            # Synthesize returns an iterator of audio chunks
+            for audio_bytes in voice.synthesize(request.text):
+                wav_file.writeframes(audio_bytes)        
         wav_buffer.seek(0)
         
         return Response(content=wav_buffer.getvalue(), media_type="audio/wav")