Add /chat/stream endpoint for Flutter compatibility

app.py

@@ -17,7 +17,9 @@ import traceback
 
 from fastapi import FastAPI, HTTPException
 from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import StreamingResponse
 from pydantic import BaseModel
+import asyncio
 import google.generativeai as genai
 
 from supabase_client import SupabaseClient
@@ -306,6 +308,47 @@ async def delete_session(session_id: str):
         raise HTTPException(500, str(e))
 
 
+@app.post("/chat/stream")
+async def chat_stream(request: ChatRequest):
+    """Stream chat response for Flutter app."""
+    logger.info(f"Stream chat - Session: {request.session_id}")
+    
+    try:
+        history = supabase.get_messages(request.session_id)
+        
+        supabase.add_message(
+            session_id=request.session_id,
+            role="user",
+            content=request.message
+        )
+        
+        response_text, context_used = generate_response(
+            request.message, history, request.field_context
+        )
+        
+        assistant_msg_id = supabase.add_message(
+            session_id=request.session_id,
+            role="assistant",
+            content=response_text,
+            context_used=context_used
+        )
+        
+        supabase.update_session_timestamp(request.session_id)
+        
+        async def stream_response():
+            yield f"data: {json.dumps({'type': 'metadata', 'session_id': request.session_id, 'message_id': assistant_msg_id})}\n\n"
+            for i in range(0, len(response_text), 15):
+                yield f"data: {json.dumps({'type': 'chunk', 'text': response_text[i:i+15]})}\n\n"
+                await asyncio.sleep(0.03)
+            yield f"data: {json.dumps({'type': 'done', 'full_text': response_text})}\n\n"
+        
+        return StreamingResponse(stream_response(), media_type="text/event-stream")
+        
+    except Exception as e:
+        logger.error(f"Stream error: {e}")
+        raise HTTPException(500, str(e))
+
+
 if __name__ == "__main__":
     import uvicorn
     logger.info("Starting AGROW Chatbot Service")