Initial commit: Gold Trading Simulator with AI-powered analysis

backend/app/services/crypto/binance_rest.py

@@ -0,0 +1,37 @@
+from __future__ import annotations
+
+import httpx
+from typing import List, Literal, Dict, Any
+
+BINANCE_REST = "https://api.binance.com/api/v3/klines"
+
+Interval = Literal["1m", "3m", "5m", "15m", "30m", "1h", "2h", "4h", "6h", "8h", "12h", "1d"]
+
+
+async def fetch_klines(symbol: str, interval: Interval, limit: int = 500) -> List[Dict[str, Any]]:
+    """
+    Fetch OHLCV klines from Binance REST. Returns list of dicts with fields:
+    time, open, high, low, close, volume
+    """
+    params = {"symbol": symbol.upper().replace("/", ""), "interval": interval, "limit": min(max(limit, 1), 1000)}
+    async with httpx.AsyncClient(timeout=15.0) as client:
+        r = await client.get(BINANCE_REST, params=params)
+        r.raise_for_status()
+        data = r.json()
+    out: List[Dict[str, Any]] = []
+    for row in data:
+        # Binance format
+        # [ openTime, open, high, low, close, volume, closeTime, ... ]
+        out.append(
+            {
+                "time": int(row[0] // 1000),
+                "open": float(row[1]),
+                "high": float(row[2]),
+                "low": float(row[3]),
+                "close": float(row[4]),
+                "volume": float(row[5]),
+            }
+        )
+    # Ensure ascending by time
+    out.sort(key=lambda x: x["time"])
+    return out