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_ETHEREUM_URL = os.getenv("OTB_BILLING_RPC_ETHEREUM", "https://ethereum-rpc.publicnode.com")
-RPC_ARBITRUM_URL = os.getenv("OTB_BILLING_RPC_ARBITRUM", "https://arb1.arbitrum.io/rpc")
+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")
 
 
 
@@ -258,40 +263,53 @@ 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 [u for u in [RPC_ARBITRUM_URL, RPC_ARBITRUM_URL_2, RPC_ARBITRUM_URL_3] if u]
-    return None
+    return []
 
-def rpc_call(rpc_url, method, params):
+def rpc_call_any(rpc_urls, method, params):
-    payload = json.dumps({
+    last_error = None
-        "jsonrpc": "2.0",
-        "id": 1,
-        "method": method,
-        "params": params,
-    }).encode("utf-8")
 
-    req = urllib.request.Request(
+    for rpc_url in rpc_urls:
-        rpc_url,
+        try:
-        data=payload,
+            payload = json.dumps({
-        headers={
+                "jsonrpc": "2.0",
-            "Content-Type": "application/json",
+                "id": 1,
-            "Accept": "application/json",
+                "method": method,
-            "User-Agent": "otb-billing-rpc/0.1",
+                "params": params,
-        },
+            }).encode("utf-8")
-        method="POST"
+
-    )
+            req = urllib.request.Request(
+                rpc_url,
+                data=payload,
+                headers={
+                    "Content-Type": "application/json",
+                    "Accept": "application/json",
+                    "User-Agent": "otb-billing-rpc/0.1",
+                },
+                method="POST"
+            )
 
-    with urllib.request.urlopen(req, timeout=20) as resp:
+            with urllib.request.urlopen(req, timeout=20) as resp:
-        data = json.loads(resp.read().decode("utf-8"))
+                data = json.loads(resp.read().decode("utf-8"))
 
-    if isinstance(data, dict) and data.get("error"):
+            if isinstance(data, dict) and data.get("error"):
-        raise RuntimeError(str(data["error"]))
+                raise RuntimeError(str(data["error"]))
+
+            return {
+                "rpc_url": rpc_url,
+                "result": (data or {}).get("result"),
+            }
+        except Exception as err:
+            last_error = err
 
-    return (data or {}).get("result")
+    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))
@@ -317,41 +335,58 @@ def parse_erc20_transfer_input(input_data):
     }
 
 def verify_wallet_transaction(option, tx_hash):
-    rpc_url = get_rpc_url_for_chain(option.get("chain"))
+    rpc_urls = get_rpc_urls_for_chain(option.get("chain"))
-    if not rpc_url:
+    if not rpc_urls:
         raise RuntimeError("No RPC configured for chain")
 
-    tx = rpc_call(rpc_url, "eth_getTransactionByHash", [tx_hash])
+    seen_result = None
-    if not tx:
+    last_not_found = False
-        raise RuntimeError("Transaction hash not found on RPC")
 
-    wallet_to = str(option.get("wallet_address") or "").lower()
+    for rpc_url in rpc_urls:
-    expected_units = _to_base_units(option.get("display_amount"), option.get("decimals") or 18)
+        try:
+            rpc_resp = rpc_call_any([rpc_url], "eth_getTransactionByHash", [tx_hash])
+            tx = rpc_resp.get("result")
+            if not tx:
+                last_not_found = True
+                continue
 
-    if option.get("asset_type") == "native":
+            wallet_to = str(option.get("wallet_address") or "").lower()
-        tx_to = str(tx.get("to") or "").lower()
+            expected_units = _to_base_units(option.get("display_amount"), option.get("decimals") or 18)
-        tx_value = int(tx.get("value") or "0x0", 16)
-        if tx_to != wallet_to:
-            raise RuntimeError("Transaction destination does not match payment wallet")
-        if tx_value != expected_units:
-            raise RuntimeError("Transaction value does not match frozen quote amount")
-    else:
-        tx_to = str(tx.get("to") or "").lower()
-        contract = str(option.get("token_contract") or "").lower()
-        if tx_to != contract:
-            raise RuntimeError("Token contract does not match expected asset contract")
-        parsed = parse_erc20_transfer_input(tx.get("input") or "")
-        if not parsed:
-            raise RuntimeError("Transaction input is not a supported ERC20 transfer")
-        if str(parsed["to"]).lower() != wallet_to:
-            raise RuntimeError("Token transfer recipient does not match payment wallet")
-        if int(parsed["amount"]) != expected_units:
-            raise RuntimeError("Token transfer amount does not match frozen quote amount")
 
-    return {
+            if option.get("asset_type") == "native":
-        "rpc_url": rpc_url,
+                tx_to = str(tx.get("to") or "").lower()
-        "tx": tx,
+                tx_value = int(tx.get("value") or "0x0", 16)
-    }
+                if tx_to != wallet_to:
+                    raise RuntimeError("Transaction destination does not match payment wallet")
+                if tx_value != expected_units:
+                    raise RuntimeError("Transaction value does not match frozen quote amount")
+            else:
+                tx_to = str(tx.get("to") or "").lower()
+                contract = str(option.get("token_contract") or "").lower()
+                if tx_to != contract:
+                    raise RuntimeError("Token contract does not match expected asset contract")
+                parsed = parse_erc20_transfer_input(tx.get("input") or "")
+                if not parsed:
+                    raise RuntimeError("Transaction input is not a supported ERC20 transfer")
+                if str(parsed["to"]).lower() != wallet_to:
+                    raise RuntimeError("Token transfer recipient does not match payment wallet")
+                if int(parsed["amount"]) != expected_units:
+                    raise RuntimeError("Token transfer amount does not match frozen quote amount")
+
+            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")))