RPC Overrides (#1057)

Author: carletex

packages/nextjs/scaffold.config.ts

@@ -4,6 +4,7 @@ export type ScaffoldConfig = {
   targetNetworks: readonly chains.Chain[];
   pollingInterval: number;
   alchemyApiKey: string;
+  rpcOverrides?: Record<number, string>;
   walletConnectProjectId: string;
   onlyLocalBurnerWallet: boolean;
 };
@@ -24,6 +25,13 @@ const scaffoldConfig = {
   // .env.local for local testing, and in the Vercel/system env config for live apps.
   alchemyApiKey: process.env.NEXT_PUBLIC_ALCHEMY_API_KEY || DEFAULT_ALCHEMY_API_KEY,
 
+  // If you want to use a different RPC for a specific network, you can add it here.
+  // The key is the chain ID, and the value is the HTTP RPC URL
+  rpcOverrides: {
+    // Example:
+    // [chains.mainnet.id]: "https://mainnet.buidlguidl.com",
+  },
+
   // This is ours WalletConnect's default project ID.
   // You can get your own at https://cloud.walletconnect.com
   // It's recommended to store it in an env variable:

packages/nextjs/services/web3/wagmiConfig.tsx

@@ -2,7 +2,7 @@ import { wagmiConnectors } from "./wagmiConnectors";
 import { Chain, createClient, fallback, http } from "viem";
 import { hardhat, mainnet } from "viem/chains";
 import { createConfig } from "wagmi";
-import scaffoldConfig, { DEFAULT_ALCHEMY_API_KEY } from "~~/scaffold.config";
+import scaffoldConfig, { DEFAULT_ALCHEMY_API_KEY, ScaffoldConfig } from "~~/scaffold.config";
 import { getAlchemyHttpUrl } from "~~/utils/scaffold-eth";
 
 const { targetNetworks } = scaffoldConfig;
@@ -19,11 +19,16 @@ export const wagmiConfig = createConfig({
   client({ chain }) {
     let rpcFallbacks = [http()];
 
-    const alchemyHttpUrl = getAlchemyHttpUrl(chain.id);
-    if (alchemyHttpUrl) {
-      const isUsingDefaultKey = scaffoldConfig.alchemyApiKey === DEFAULT_ALCHEMY_API_KEY;
-      // If using default Scaffold-ETH 2 API key, we prioritize the default RPC
-      rpcFallbacks = isUsingDefaultKey ? [http(), http(alchemyHttpUrl)] : [http(alchemyHttpUrl), http()];
+    const rpcOverrideUrl = (scaffoldConfig.rpcOverrides as ScaffoldConfig["rpcOverrides"])?.[chain.id];
+    if (rpcOverrideUrl) {
+      rpcFallbacks = [http(rpcOverrideUrl), http()];
+    } else {
+      const alchemyHttpUrl = getAlchemyHttpUrl(chain.id);
+      if (alchemyHttpUrl) {
+        const isUsingDefaultKey = scaffoldConfig.alchemyApiKey === DEFAULT_ALCHEMY_API_KEY;
+        // If using default Scaffold-ETH 2 API key, we prioritize the default RPC
+        rpcFallbacks = isUsingDefaultKey ? [http(), http(alchemyHttpUrl)] : [http(alchemyHttpUrl), http()];
+      }
     }
 
     return createClient({