Initial commit: Gold Trading Simulator with AI-powered analysis

backend/app/providers/crypto/binance_ws.py

@@ -0,0 +1,50 @@
+from __future__ import annotations
+
+import asyncio
+import json
+import websockets
+from typing import AsyncIterator
+from datetime import datetime
+
+from ..typing import Kline
+import os
+
+
+class BinanceWSProvider:
+    def __init__(self, base_url: str | None = None):
+        self.base_url = base_url or os.getenv("BINANCE_WS_URL", "wss://stream.binance.com:9443/ws")
+
+    async def stream_klines(self, symbol: str, timeframe: str) -> AsyncIterator[Kline]:
+        # Binance expects lowercase, no slash: BTCUSDT -> btcusdt
+        stream = f"{symbol.lower()}@kline_{timeframe}"
+        url = self.base_url.rstrip("/").replace("/ws", "/stream") + f"?streams={stream}"
+        async for msg in self._ws_loop(url):
+            try:
+                data = json.loads(msg)
+                k = data.get("data", {}).get("k", {})
+                if not k:
+                    continue
+                yield Kline(
+                    symbol=symbol,
+                    timeframe=timeframe,
+                    open_time=datetime.fromtimestamp(k["t"] / 1000.0),
+                    close_time=datetime.fromtimestamp(k["T"] / 1000.0),
+                    open=float(k["o"]),
+                    high=float(k["h"]),
+                    low=float(k["l"]),
+                    close=float(k["c"]),
+                    volume=float(k.get("v", 0.0)),
+                    is_closed=bool(k.get("x", False)),
+                    source="binance",
+                )
+            except Exception:
+                continue
+
+    async def _ws_loop(self, url: str):
+        while True:
+            try:
+                async with websockets.connect(url, ping_interval=20, ping_timeout=20) as ws:
+                    async for message in ws:
+                        yield message
+            except Exception:
+                await asyncio.sleep(2)