Sponsor gas with Pimlico

import { createPublicClient, http } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';
import { seiTestnet } from 'viem/chains';
import { createSmartAccountClient } from 'permissionless';
import { toSimpleSmartAccount } from 'permissionless/accounts';
import { createPimlicoClient } from 'permissionless/clients/pimlico';

const pimlicoUrl = `https://api.pimlico.io/v2/${seiTestnet.id}/rpc?apikey=${process.env.PIMLICO_API_KEY}`;

const publicClient = createPublicClient({ chain: seiTestnet, transport: http() });
const pimlicoClient = createPimlicoClient({ chain: seiTestnet, transport: http(pimlicoUrl) });

// A smart account that a single private key controls
const account = await toSimpleSmartAccount({
  client: publicClient,
  owner: privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`),
});
console.log('Smart account:', account.address);

const smartAccountClient = createSmartAccountClient({
  account,
  chain: seiTestnet,
  bundlerTransport: http(pimlicoUrl),
  paymaster: pimlicoClient,
  userOperation: {
    estimateFeesPerGas: async () => (await pimlicoClient.getUserOperationGasPrice()).fast,
  },
});

const hash = await smartAccountClient.sendTransaction({
  to: '0xd8da6bf26964af9d7eed9e03e53415d37aa96045',
  value: 0n,
  data: '0x1234',
});
console.log('Transaction hash:', hash);