Add 3-RPC polling pools for Ethereum and Arbitrum

backend/app.py

@@ -50,8 +50,13 @@ SQUARE_API_VERSION = "2026-01-22"
 SQUARE_WEBHOOK_LOG = str(BASE_DIR / "logs" / "square_webhook_events.log")
 ORACLE_BASE_URL = os.getenv("ORACLE_BASE_URL", "https://monitor.outsidethebox.top")
 CRYPTO_EVM_PAYMENT_ADDRESS = os.getenv("OTB_BILLING_CRYPTO_EVM_ADDRESS", "0x44f6c44C42e6ae0392E7289F032384C0d37F56D5")
-RPC_ETHEREUM_URL = os.getenv("OTB_BILLING_RPC_ETHEREUM", "https://cloudflare-eth.com")
-RPC_ARBITRUM_URL = os.getenv("OTB_BILLING_RPC_ARBITRUM", "https://arb1.arbitrum.io/rpc")
+RPC_ETHEREUM_URL = os.getenv("OTB_BILLING_RPC_ETHEREUM", "https://ethereum-rpc.publicnode.com")
+RPC_ETHEREUM_URL_2 = os.getenv("OTB_BILLING_RPC_ETHEREUM_2", "https://rpc.ankr.com/eth")
+RPC_ETHEREUM_URL_3 = os.getenv("OTB_BILLING_RPC_ETHEREUM_3", "https://eth.drpc.org")
+
+RPC_ARBITRUM_URL = os.getenv("OTB_BILLING_RPC_ARBITRUM", "https://arbitrum-one-rpc.publicnode.com")
+RPC_ARBITRUM_URL_2 = os.getenv("OTB_BILLING_RPC_ARBITRUM_2", "https://rpc.ankr.com/arbitrum")
+RPC_ARBITRUM_URL_3 = os.getenv("OTB_BILLING_RPC_ARBITRUM_3", "https://arb1.arbitrum.io/rpc")
 
 
 
@@ -258,15 +263,19 @@ def get_invoice_crypto_options(invoice):
     options.sort(key=lambda x: (0 if x.get("recommended") else 1, x.get("symbol")))
     return options
 
-def get_rpc_url_for_chain(chain_name):
+def get_rpc_urls_for_chain(chain_name):
     chain = str(chain_name or "").lower()
     if chain == "ethereum":
-        return RPC_ETHEREUM_URL
+        return [u for u in [RPC_ETHEREUM_URL, RPC_ETHEREUM_URL_2, RPC_ETHEREUM_URL_3] if u]
     if chain == "arbitrum":
-        return RPC_ARBITRUM_URL
-    return None
+        return [u for u in [RPC_ARBITRUM_URL, RPC_ARBITRUM_URL_2, RPC_ARBITRUM_URL_3] if u]
+    return []
+
+def rpc_call_any(rpc_urls, method, params):
+    last_error = None
 
-def rpc_call(rpc_url, method, params):
+    for rpc_url in rpc_urls:
+        try:
             payload = json.dumps({
                 "jsonrpc": "2.0",
                 "id": 1,
@@ -291,7 +300,16 @@ def rpc_call(rpc_url, method, params):
             if isinstance(data, dict) and data.get("error"):
                 raise RuntimeError(str(data["error"]))
 
-    return (data or {}).get("result")
+            return {
+                "rpc_url": rpc_url,
+                "result": (data or {}).get("result"),
+            }
+        except Exception as err:
+            last_error = err
+
+    if last_error:
+        raise last_error
+    raise RuntimeError("No RPC URLs configured")
 
 def _to_base_units(amount_text, decimals):
     amount_dec = Decimal(str(amount_text))
@@ -317,13 +335,20 @@ def parse_erc20_transfer_input(input_data):
     }
 
 def verify_wallet_transaction(option, tx_hash):
-    rpc_url = get_rpc_url_for_chain(option.get("chain"))
-    if not rpc_url:
+    rpc_urls = get_rpc_urls_for_chain(option.get("chain"))
+    if not rpc_urls:
         raise RuntimeError("No RPC configured for chain")
 
-    tx = rpc_call(rpc_url, "eth_getTransactionByHash", [tx_hash])
+    seen_result = None
+    last_not_found = False
+
+    for rpc_url in rpc_urls:
+        try:
+            rpc_resp = rpc_call_any([rpc_url], "eth_getTransactionByHash", [tx_hash])
+            tx = rpc_resp.get("result")
             if not tx:
-        raise RuntimeError("Transaction hash not found on RPC")
+                last_not_found = True
+                continue
 
             wallet_to = str(option.get("wallet_address") or "").lower()
             expected_units = _to_base_units(option.get("display_amount"), option.get("decimals") or 18)
@@ -348,10 +373,20 @@ def verify_wallet_transaction(option, tx_hash):
                 if int(parsed["amount"]) != expected_units:
                     raise RuntimeError("Token transfer amount does not match frozen quote amount")
 
-    return {
+            seen_result = {
                 "rpc_url": rpc_url,
                 "tx": tx,
             }
+            break
+        except Exception:
+            continue
+
+    if not seen_result:
+        if last_not_found:
+            raise RuntimeError("Transaction hash not found on any configured RPC")
+        raise RuntimeError("Unable to verify transaction on configured RPC pool")
+
+    return seen_result
 
 def square_amount_to_cents(value):
     return int((to_decimal(value) * 100).quantize(Decimal("1")))