market movers v4 complement fallback

backend/routers/expanded_market_api.py

@@ -219,6 +219,25 @@ async def fetch_market_movers(limit: int) -> tuple[List[dict], str]:
             logger.warning("CoinPaprika movers failed, trying Binance...")
             rows = await _fetch_markets_from_binance(limit)
             source = "binance"
+        if not rows:
+            logger.warning("Binance movers failed, trying v4 complement Space...")
+            try:
+                from backend.services.v4_complement_client import get_market_gainers
+                v4 = await get_market_gainers(limit)
+                if v4.get("success"):
+                    v4data = v4.get("data") or {}
+                    for g in v4data.get("gainers") or []:
+                        rows.append(_normalize_market_row({
+                            "symbol": g.get("symbol"),
+                            "name": g.get("name"),
+                            "priceUsd": g.get("price"),
+                            "changePercent24Hr": g.get("change_24h"),
+                            "volumeUsd24Hr": g.get("volume_24h"),
+                        }, "v4_complement"))
+                    if rows:
+                        source = "v4_complement"
+            except Exception as v4_err:
+                logger.warning("v4 complement movers failed: %s", v4_err)
 
     if not rows:
         raise HTTPException(status_code=503, detail="All market mover providers unavailable")