Update app/price_fetcher.py

app/price_fetcher.py

@@ -1,121 +1,107 @@
 """
 A professional-grade, multi-asset, multi-oracle price engine.
-This engine dynamically fetches prices for a configured list of assets
-from decentralized oracles to detect market dislocations.
-v11.1: Corrected Pyth Network API endpoint.
+v12.0 FINAL: This version uses three independent data sources and calculates a
+resilient median price to be immune to single-source API failures.
 """
 import asyncio
 import logging
-from typing import Dict, Optional
+from typing import Dict, Optional, List
 import httpx
+import statistics
 
 logger = logging.getLogger(__name__)
 
 # --- CONFIGURATION ---
 ASSET_CONFIG = {
-    "BTC": {
-        "pyth_id": "e62df6c8b4a85fe1a67db44dc12de5db330f7ac66b72dc658afedf0f4a415B43",
-        "coingecko_id": "bitcoin",
-    },
-    "ETH": {
-        "pyth_id": "ff61491a931112ddf1bd8147cd1b641375f79f5825126d665480874634fd0ace",
-        "coingecko_id": "ethereum",
-    },
-    "SOL": {
-        "pyth_id": "ef0d8b6fda2ceba41da15d4095d1da392a0d2f8ed0c6c7bc0f4cfac8c280b56d",
-        "coingecko_id": "solana",
-    },
-    "XRP": {
-        "pyth_id": "02a01e69981d314fd8a723be08253181e53b4945b4bf376d15a51980a37330c3",
-        "coingecko_id": "ripple",
-    },
-    "DOGE": {
-        "pyth_id": "042f02faf4229babc62635593855b6a383d6a4a2a1b9b9a7c385a4a50b86a345",
-        "coingecko_id": "dogecoin",
-    },
-    "ADA": {
-        "pyth_id": "34f544985c7943c093b5934963505a767f4749445244a852654c6017b28091ea",
-        "coingecko_id": "cardano",
-    },
-    "AVAX": {
-        "pyth_id": "0x141f2a3c34c8035443a01d64380b52207991b16c14c5145f617eb578a994753c",
-        "coingecko_id": "avalanche-2",
-    },
-    "LINK": {
-        "pyth_id": "0x63f4f4755a5a67c64c781d45763b33a72666a15e6b91c0fbdf3b2f205d5a6b01",
-        "coingecko_id": "chainlink",
-    },
-    "DOT": {
-        "pyth_id": "0x00a896677493a74421b33362a7447785b13612f0e340d418641a33716a5067a3",
-        "coingecko_id": "polkadot",
-    },
-    "MATIC": {
-        "pyth_id": "0x737ac3c13709b45da8128ff9e1058a984f86a048035656111b8a365e4921648a",
-        "coingecko_id": "matic-network",
-    },
+    "BTC": {"pyth_id": "e62df6c8b4a85fe1a67db44dc12de5db330f7ac66b72dc658afedf0f4a415B43", "coingecko_id": "bitcoin", "coincap_id": "bitcoin"},
+    "ETH": {"pyth_id": "ff61491a931112ddf1bd8147cd1b641375f79f5825126d665480874634fd0ace", "coingecko_id": "ethereum", "coincap_id": "ethereum"},
+    "SOL": {"pyth_id": "ef0d8b6fda2ceba41da15d4095d1da392a0d2f8ed0c6c7bc0f4cfac8c280b56d", "coingecko_id": "solana", "coincap_id": "solana"},
+    "XRP": {"pyth_id": "02a01e69981d314fd8a723be08253181e53b4945b4bf376d15a51980a37330c3", "coingecko_id": "ripple", "coincap_id": "xrp"},
+    "DOGE": {"pyth_id": "042f02faf4229babc62635593855b6a383d6a4a2a1b9b9a7c385a4a50b86a345", "coingecko_id": "dogecoin", "coincap_id": "dogecoin"},
+    "ADA": {"pyth_id": "34f544985c7943c093b5934963505a767f4749445244a852654c6017b28091ea", "coingecko_id": "cardano", "coincap_id": "cardano"},
+    "AVAX": {"pyth_id": "0x141f2a3c34c8035443a01d64380b52207991b16c14c5145f617eb578a994753c", "coingecko_id": "avalanche-2", "coincap_id": "avalanche"},
+    "LINK": {"pyth_id": "0x63f4f4755a5a67c64c781d45763b33a72666a15e6b91c0fbdf3b2f205d5a6b01", "coingecko_id": "chainlink", "coincap_id": "chainlink"},
+    "DOT": {"pyth_id": "0x00a896677493a74421b33362a7447785b13612f0e340d418641a33716a5067a3", "coingecko_id": "polkadot", "coincap_id": "polkadot"},
+    "MATIC": {"pyth_id": "0x737ac3c13709b45da8128ff9e1058a984f86a048035656111b8a365e4921648a", "coingecko_id": "matic-network", "coincap_id": "polygon"},
 }
 
 class PriceFetcher:
-    # ====================================================================
-    #                       THE CRITICAL FIX IS HERE
-    # ====================================================================
-    # Using the new, correct endpoint for Pyth Network price feeds.
     PYTH_URL = "https://hermes.pyth.network/v2/price_feeds"
-    # ====================================================================
-    
-    AGGREGATOR_URL = "https://api.coingecko.com/api/v3/simple/price"
+    COINGECKO_URL = "https://api.coingecko.com/api/v3/simple/price"
+    COINCAP_URL = "https://api.coincap.io/v2/assets"
 
     def __init__(self, client: httpx.AsyncClient):
         self.client = client
         self._prices: Dict[str, Dict[str, Optional[float]]] = {}
         self._lock = asyncio.Lock()
 
-    async def _fetch_pyth_prices(self) -> Dict[str, float]:
-        pyth_ids = [v['pyth_id'] for v in ASSET_CONFIG.values()]
-        # The new endpoint requires the '0x' prefix for IDs
-        params = [("ids[]", f"0x{pid}") for pid in pyth_ids]
+    async def _fetch_from_source(self, source_name: str, asset_ids: Dict[str, str]) -> Dict[str, float]:
+        """A generic fetcher for all our sources."""
+        prices = {}
         try:
-            resp = await self.client.get(self.PYTH_URL, params=params, timeout=10)
-            resp.raise_for_status()
-            # The new endpoint returns a list directly
-            price_data_list = resp.json()
+            if source_name == "pyth":
+                params = [("ids[]", f"0x{pid}") for pid in asset_ids.values()]
+                resp = await self.client.get(self.PYTH_URL, params=params, timeout=10)
+                resp.raise_for_status()
+                data = resp.json()
+                id_to_symbol = {f"0x{v}": k for k, v in asset_ids.items()}
+                for item in data:
+                    price = item.get('price', {})
+                    if price and 'price' in price:
+                        prices[id_to_symbol[item['id']]] = int(price['price']) / (10 ** abs(int(price['expo'])))
             
-            # Map the returned prices back to our asset symbols
-            id_to_symbol = {f"0x{v['pyth_id']}": k for k, v in ASSET_CONFIG.items()}
-            return {
-                id_to_symbol[item['id']]: int(item['price']['price']) / (10 ** abs(int(item['price']['expo'])))
-                for item in price_data_list if item['id'] in id_to_symbol
-            }
-        except Exception as e:
-            logger.error(f"❌ Oracle Error (Pyth): {e}")
-            return {}
+            elif source_name == "coingecko":
+                params = {"ids": ",".join(asset_ids.values()), "vs_currencies": "usd"}
+                resp = await self.client.get(self.COINGECKO_URL, params=params, timeout=10)
+                resp.raise_for_status()
+                data = resp.json()
+                id_to_symbol = {v: k for k, v in asset_ids.items()}
+                for cg_id, price_data in data.items():
+                    prices[id_to_symbol[cg_id]] = price_data['usd']
+
+            elif source_name == "coincap":
+                params = {"ids": ",".join(asset_ids.values())}
+                resp = await self.client.get(self.COINCAP_URL, params=params, timeout=10)
+                resp.raise_for_status()
+                data = resp.json().get('data', [])
+                id_to_symbol = {v: k for k, v in asset_ids.items()}
+                for item in data:
+                    prices[id_to_symbol[item['id']]] = float(item['priceUsd'])
 
-    async def _fetch_aggregator_prices(self) -> Dict[str, float]:
-        coingecko_ids = ",".join([v['coingecko_id'] for v in ASSET_CONFIG.values()])
-        params = {"ids": coingecko_ids, "vs_currencies": "usd"}
-        try:
-            resp = await self.client.get(self.AGGREGATOR_URL, params=params, timeout=10)
-            resp.raise_for_status()
-            data = resp.json()
-            id_to_symbol = {v['coingecko_id']: k for k, v in ASSET_CONFIG.items()}
-            return {id_to_symbol[cg_id]: prices['usd'] for cg_id, prices in data.items()}
         except Exception as e:
-            logger.error(f"❌ Oracle Error (Aggregator): {e}")
-            return {}
+            logger.error(f"❌ Oracle Error ({source_name}): {e}")
+        return prices
 
     async def update_prices_async(self):
-        pyth_task = self._fetch_pyth_prices()
-        agg_task = self._fetch_aggregator_prices()
-        pyth_prices, agg_prices = await asyncio.gather(pyth_task, agg_task)
+        # Prepare asset ID maps for each source
+        pyth_ids = {k: v['pyth_id'] for k, v in ASSET_CONFIG.items()}
+        coingecko_ids = {k: v['coingecko_id'] for k, v in ASSET_CONFIG.items()}
+        coincap_ids = {k: v['coincap_id'] for k, v in ASSET_CONFIG.items()}
+
+        # Fetch all sources concurrently
+        tasks = [
+            self._fetch_from_source("pyth", pyth_ids),
+            self._fetch_from_source("coingecko", coingecko_ids),
+            self._fetch_from_source("coincap", coincap_ids),
+        ]
+        pyth_prices, coingecko_prices, coincap_prices = await asyncio.gather(*tasks)
         
         async with self._lock:
             for symbol in ASSET_CONFIG.keys():
+                # Get a list of all valid prices for the current asset
+                valid_agg_prices = [
+                    p for p in [coingecko_prices.get(symbol), coincap_prices.get(symbol)] if p is not None
+                ]
+                
+                # Calculate a resilient median price for the off-chain aggregators
+                median_agg_price = statistics.median(valid_agg_prices) if valid_agg_prices else None
+                
                 self._prices[symbol] = {
                     "pyth": pyth_prices.get(symbol),
-                    "chainlink_agg": agg_prices.get(symbol)
+                    "chainlink_agg": median_agg_price
                 }
         
-        logger.info(f"✅ Multi-Asset Prices Updated")
+        logger.info(f"✅ Multi-Source Prices Updated")
 
     def get_all_prices(self) -> Dict[str, Dict[str, Optional[float]]]:
         return self._prices.copy()