chore: use a proxy for alchemy

.env.example

@@ -1,6 +1,6 @@
 VITE_BASE_URL=
 
-VITE_ALCHEMY_API_KEY=
+VITE_ALCHEMY_RPC_PROXY_URL=
 
 VITE_PRIVY_APP_ID=
 VITE_PRIVY_APP_CLIENT_ID=

README.md

@@ -76,7 +76,7 @@ You'll need to provide a Wallet Connect project id to enable onboarding and wall
 Set environment variables via `.env`.
 
 - `VITE_BASE_URL` (required): The base URL of the deployment (e.g., `https://www.example.com`).
-- `VITE_ALCHEMY_API_KEY` (optional): Add an Alchemy API key for EVM interactions; the app will fall back to public RPCs if not provided.
+- `VITE_ALCHEMY_RPC_PROXY_URL` (optional): Base URL of your Alchemy proxy for EVM RPC requests; the proxy injects the secret Alchemy API key so it is not exposed in the web app (e.g., `https://proxy.example.com`).
 - `VITE_PK_ENCRYPTION_KEY` (optional): AES encryption key used for signature obfuscation; necessary for enabling the "Remember Me" feature.
 - `VITE_V3_TOKEN_ADDRESS` (optional): Address of the V3 $DYDX token.
 - `VITE_TOKEN_MIGRATION_URI` (optional): The URL of the token migration website.

src/lib/wagmi.ts

@@ -110,33 +110,34 @@ export enum ChainId {
 }
 
 export const getAlchemyRPCUrlForChainId = (chainId: ChainId) => {
-  const alchemyKey = import.meta.env.VITE_ALCHEMY_API_KEY;
-  if (!alchemyKey) return undefined;
+  const alchemyRpcProxyUrl = import.meta.env.VITE_ALCHEMY_RPC_PROXY_URL;
+  if (!alchemyRpcProxyUrl) return undefined;
+
   switch (chainId) {
     case ChainId.ETH_MAINNET:
-      return `https://eth-mainnet.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/eth-mainnet/v2`;
     case ChainId.ETH_SEPOLIA:
-      return `https://eth-sepolia.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/eth-sepolia/v2`;
     case ChainId.POLYGON_MAINNET:
-      return `https://polygon-mainnet.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/polygon-mainnet/v2`;
     case ChainId.POLYGON_MUMBAI:
-      return `https://polygon-amoy.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/polygon-amoy/v2`;
     case ChainId.OPT_MAINNET:
-      return `https://opt-mainnet.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/opt-mainnet/v2`;
     case ChainId.OPT_SEPOLIA:
-      return `https://opt-sepolia.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/opt-sepolia/v2`;
     case ChainId.ARB_MAINNET:
-      return `https://arb-mainnet.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/arb-mainnet/v2`;
     case ChainId.ARB_SEPOLIA:
-      return `https://arb-sepolia.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/arb-sepolia/v2`;
     case ChainId.BASE_MAINNET:
-      return `https://base-mainnet.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/base-mainnet/v2`;
     case ChainId.BASE_SEPOLIA:
-      return `https://base-sepolia.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/base-sepolia/v2`;
     case ChainId.AVALANCHE_MAINNET:
-      return `https://avax-mainnet.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/avax-mainnet/v2`;
     case ChainId.AVALANCHE_FUJI:
-      return `https://avax-fuji.g.alchemy.com/v2/${alchemyKey}`;
+      return `${alchemyRpcProxyUrl}/avax-fuji/v2`;
     default:
       return undefined;
   }