Update app/main.py

app/main.py

@@ -1,8 +1,9 @@
 """
-Sentinel Arbitrage Engine - v20.0 FINAL (Raw Stream)
+Sentinel Arbitrage Engine - v20.1 FINAL (Syntax Fix)
 
 This version uses a file-based log and a raw, unstoppable streaming
-endpoint to guarantee signal delivery. This is the final architecture.
+endpoint to guarantee signal delivery. This version corrects the async
+generator syntax.
 """
 import asyncio
 import os
@@ -11,10 +12,12 @@ import time
 from contextlib import asynccontextmanager
 from datetime import datetime, timezone
 import httpx
-from fastapi import FastAPI
-from fastapi.staticfiles import StaticFiles
+from fastapi import FastAPI, Request
 from fastapi.responses import StreamingResponse
+from fastapi.staticfiles import StaticFiles
 
+# --- RELATIVE IMPORTS ---
+# This assumes your project is structured with an 'app' package.
 from .price_fetcher import PriceFetcher
 from .arbitrage_analyzer import ArbitrageAnalyzer
 
@@ -23,7 +26,8 @@ SIGNALS_FILE = "signals.log"
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
-    if os.path.exists(SIGNALS_FILE): os.remove(SIGNALS_FILE)
+    if os.path.exists(SIGNALS_FILE):
+        os.remove(SIGNALS_FILE)
     
     async with httpx.AsyncClient() as client:
         price_fetcher = PriceFetcher(client)
@@ -32,7 +36,7 @@ async def lifespan(app: FastAPI):
         app.state.engine_task = asyncio.create_task(
             run_arbitrage_detector(price_fetcher, arbitrage_analyzer)
         )
-        print("🚀 Sentinel Engine v20.0 (Raw Stream) is ONLINE.")
+        print("🚀 Sentinel Engine v20.1 (Syntax Fix) is ONLINE.")
         yield
         app.state.engine_task.cancel()
         print("✅ Engine shut down.")
@@ -57,7 +61,6 @@ async def run_arbitrage_detector(price_fetcher, analyzer):
                             briefing = await analyzer.get_alpha_briefing(asset, opportunity)
                             if briefing:
                                 signal = {**opportunity, **briefing, "timestamp": datetime.now(timezone.utc).isoformat()}
-                                # --- THE FIX: Append as a single line to a log file ---
                                 with open(SIGNALS_FILE, "a") as f:
                                     f.write(json.dumps(signal) + "\n")
                                 print(f"✅ Signal LOGGED for {asset}")
@@ -68,14 +71,15 @@ async def run_arbitrage_detector(price_fetcher, analyzer):
 # --- FastAPI App Setup ---
 app = FastAPI(lifespan=lifespan)
 
+# --- API Endpoints ---
 @app.get("/api/signals/stream")
 async def signal_stream():
     """This endpoint streams the content of the signals.log file line by line."""
     async def event_generator():
-        # Use an async-compatible way to tail the file
         try:
             with open(SIGNALS_FILE, 'r') as f:
-                f.seek(0, 2) # Go to the end of the file
+                # Go to the end of the file
+                f.seek(0, 2) 
                 while True:
                     line = f.readline()
                     if not line:
@@ -88,9 +92,15 @@ async def signal_stream():
             # Keep the connection open and wait for the file to be created
             while not os.path.exists(SIGNALS_FILE):
                 await asyncio.sleep(1)
-            # Re-run the generator now that the file exists
-            yield from event_generator()
+            # ====================================================================
+            #                       THE CRITICAL FIX IS HERE
+            # ====================================================================
+            # Use 'async for' to correctly delegate to the async generator
+            async for line in event_generator():
+                yield line
+            # ====================================================================
 
     return StreamingResponse(event_generator(), media_type="text/plain")
 
-app.mount("/", StaticFiles(directory="static", html=True), name="static")
+# Mount static files to serve index.html at the root
+app.mount("/", StaticFiles(directory="static", html=True), name="static")