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backend/hardhat.config.js

@@ -1,6 +1,26 @@
 require('@nomicfoundation/hardhat-toolbox');
 require('dotenv').config();
 
+function getNetworks() {
+  const supported = [
+    { id: 'bsc', envUrl: 'BSC_RPC_URL', envKey: 'BSC_PRIVATE_KEY' },
+    { id: 'ethereum', envUrl: 'ETHEREUM_RPC_URL', envKey: 'ETHEREUM_PRIVATE_KEY' },
+    { id: 'arbitrum', envUrl: 'ARBITRUM_RPC_URL', envKey: 'ARBITRUM_PRIVATE_KEY' },
+    { id: 'polygon', envUrl: 'POLYGON_RPC_URL', envKey: 'POLYGON_PRIVATE_KEY' },
+    { id: 'sepolia', envUrl: 'SEPOLIA_RPC_URL', envKey: 'SEPOLIA_PRIVATE_KEY' },
+  ];
+  const networks = {};
+  for (const net of supported) {
+    if (process.env[net.envUrl] && process.env[net.envKey]) {
+      networks[net.id] = {
+        url: process.env[net.envUrl],
+        accounts: [process.env[net.envKey]],
+      };
+    }
+  }
+  return networks;
+}
+
 module.exports = {
   solidity: {
     version: "0.8.20",
@@ -12,10 +32,5 @@ module.exports = {
       viaIR: true
     }
   },
-  networks: {
-    sepolia: {
-      url: process.env.RPC_URL_ETH,
-      accounts: [process.env.PRIVATE_KEY],
-    },
-  },
+  networks: getNetworks(),
 };