fix(sdk): use transaction-specified chain in smart account

Author: gregfromstl

.changeset/fair-planes-doubt.md

@@ -0,0 +1,5 @@
+---
+"thirdweb": patch
+---
+
+SDK: Fix chain switching in smart account transactions

packages/thirdweb/src/wallets/smart/index.ts

@@ -240,15 +240,30 @@ async function createSmartAccount(
       } else {
         paymasterOverride = options.overrides?.paymaster;
       }
+
+      const accountContractForTransaction = (() => {
+        // If this transaction is for a different chain than the initial one, get the account contract for that chain
+        if (transaction.chainId !== accountContract.chain.id) {
+          return getContract({
+            address: account.address,
+            chain: getCachedChain(transaction.chainId),
+            client: options.client,
+          });
+        }
+        // Default to the existing account contract
+        return accountContract;
+      })();
+
       const executeTx = prepareExecute({
-        accountContract,
+        accountContract: accountContractForTransaction,
         transaction,
         executeOverride: options.overrides?.execute,
       });
       return _sendUserOp({
         executeTx,
         options: {
           ...options,
+          chain: getCachedChain(transaction.chainId),
           overrides: {
             ...options.overrides,
             paymaster: paymasterOverride,

packages/thirdweb/src/wallets/smart/smart-wallet-integration.test.ts

@@ -26,6 +26,7 @@ import type { Account, Wallet } from "../interfaces/wallet.js";
 import { generateAccount } from "../utils/generateAccount.js";
 import { predictSmartAccountAddress } from "./lib/calls.js";
 import { smartWallet } from "./smart-wallet.js";
+import { TEST_WALLET_A } from "~test/addresses.js";
 
 let wallet: Wallet;
 let smartAccount: Account;
@@ -309,6 +310,19 @@ describe.runIf(process.env.TW_SECRET_KEY).sequential(
       expect(wallet.getChain()?.id).toEqual(baseSepolia.id);
     });
 
+    it("can send a transaction on another chain", async () => {
+      const tx = await sendAndConfirmTransaction({
+        transaction: prepareTransaction({
+          to: TEST_WALLET_A,
+          client: TEST_CLIENT,
+          chain: baseSepolia,
+          value: 0n,
+        }),
+        account: wallet.getAccount()!,
+      });
+      expect(tx.transactionHash).toHaveLength(66);
+    });
+
     it("can execute 2 tx in parallel", async () => {
       const newSmartWallet = smartWallet({
         chain,