Without Batching:
TX 1: Approve USDC    → Wait → Confirm → Pay gas
TX 2: Deposit to Aave → Wait → Confirm → Pay gas
TX 3: Claim rewards   → Wait → Confirm → Pay gas
Total: 3 signatures, 3 gas payments, 3 confirmations

With Batching:
TX 1: [Approve + Deposit + Claim] → Single signature → Single gas payment
Total: 1 signature, 1 gas payment, atomic execution

import { createMeeClient, toMultichainNexusAccount } from "@biconomy/abstractjs";
import { encodeFunctionData } from "viem";

const account = await toMultichainNexusAccount({
  signer: userSigner,
  chains: [base]
});

const meeClient = await createMeeClient({ account });

// Batch multiple operations with MEE
const quote = await meeClient.getQuote({
  instructions: [
    {
      calls: [
        {
          to: usdcAddress,
          data: encodeFunctionData({
            abi: erc20Abi,
            functionName: "approve",
            args: [aavePool, amount]
          })
        },
        {
          to: aavePool,
          data: encodeFunctionData({
            abi: aaveAbi,
            functionName: "deposit",
            args: [usdcAddress, amount, userAddress, 0]
          })
        },
        {
          to: rewardsController,
          data: encodeFunctionData({
            abi: rewardsAbi,
            functionName: "claimAllRewards",
            args: [assets, userAddress]
          })
        }
      ]
    }
  ]
});

const { hash } = await meeClient.executeQuote({ quote });
console.log("All operations completed in one tx:", hash);

const transfers = recipients.map(({ address, amount }) => ({
  to: tokenAddress,
  data: encodeFunctionData({
    abi: erc20Abi,
    functionName: "transfer",
    args: [address, amount]
  })
}));

// Send to 100 recipients in ONE transaction
await smartAccount.sendTransactions(transfers);

Scenario: Approve USDC → Swap USDC for ETH

Non-atomic (separate txs):
1. Approve succeeds ✅
2. Swap fails (price changed) ❌
Result: Approval is stuck, USDC still approved to router 😰

Atomic (batched):
1. [Approve + Swap] fails ❌
Result: Nothing happened, state unchanged 😌

try {
  const { hash } = await smartAccount.sendTransactions([
    { /* operation 1 */ },
    { /* operation 2 */ },
    { /* operation 3 */ }
  ]);
  // All succeeded
} catch (error) {
  // ALL operations reverted, no partial state
  console.log("Batch failed atomically");
}

import { runtime } from "@biconomy/abstractjs";

const instructions = [
  // Step 1: Swap ETH for USDC (output unknown until execution)
  {
    type: "intent",
    intent: "swap",
    params: {
      from: "ETH",
      to: "USDC",
      amount: "1.0"
    }
  },
  // Step 2: Use EXACT output from step 1
  {
    to: aavePool,
    data: encodeDeposit(
      usdcAddress,
      runtime.outputOf(0), // Dynamic: uses actual swap output
      userAddress
    )
  }
];

// Split large batches
const BATCH_SIZE = 20;

async function batchTransfer(transfers) {
  const results = [];
  
  for (let i = 0; i < transfers.length; i += BATCH_SIZE) {
    const batch = transfers.slice(i, i + BATCH_SIZE);
    const result = await smartAccount.sendTransactions(batch);
    results.push(result);
  }
  
  return results;
}

// Estimate gas for batch
const gasEstimate = await smartAccount.estimateGas({
  transactions: [
    { to: contract1, data: data1 },
    { to: contract2, data: data2 },
    { to: contract3, data: data3 }
  ]
});

console.log("Total gas estimate:", gasEstimate);

// Compare with individual estimates
const individual1 = await publicClient.estimateGas({ to: contract1, data: data1 });
const individual2 = await publicClient.estimateGas({ to: contract2, data: data2 });
const individual3 = await publicClient.estimateGas({ to: contract3, data: data3 });

const totalIndividual = individual1 + individual2 + individual3;
const savings = totalIndividual - gasEstimate;

console.log(`Gas savings from batching: ${savings} (${(savings/totalIndividual*100).toFixed(1)}%)`);

try {
  await smartAccount.sendTransactions([op1, op2, op3]);
} catch (error) {
  // Entire batch reverted
  // Identify which operation failed from error message
  console.log("Batch failed:", error.message);
}

const { conditions } = require("@biconomy/abstractjs");

const transactions = [
  // Critical: Always execute
  { to: contract1, data: data1 },
  
  // Optional: Only if balance exists
  {
    to: contract2,
    data: data2,
    condition: conditions.hasBalance(tokenAddress, minAmount)
  },
  
  // Optional: Only if previous succeeded
  {
    to: contract3,
    data: data3,
    condition: conditions.previousSucceeded()
  }
];

async function validateBatch(transactions) {
  const simulations = await Promise.all(
    transactions.map(tx => 
      publicClient.simulateContract({
        address: tx.to,
        data: tx.data
      }).catch(e => ({ error: e }))
    )
  );
  
  const failures = simulations.filter(s => s.error);
  if (failures.length > 0) {
    console.log("Operations that would fail:", failures);
    return false;
  }
  return true;
}

const crossChainBatch = {
  instructions: [
    // Chain 1: Ethereum
    {
      chainId: 1,
      to: usdcEthereum,
      data: encodeApprove(bridge, amount)
    },
    // Bridge operation
    {
      type: "intent",
      intent: "bridge",
      params: { token: "USDC", from: 1, to: 8453, amount }
    },
    // Chain 2: Base
    {
      chainId: 8453,
      to: aaveBase,
      data: encodeDeposit(usdcBase, runtime.bridgeOutput, user)
    }
  ]
};

// One signature covers all chains
const result = await meeClient.execute(crossChainBatch);

// Claim rewards → Swap to stablecoin → Redeposit
await smartAccount.sendTransactions([
  // Claim pending rewards
  { to: farm, data: encodeClaim() },
  // Approve swap
  { to: rewardToken, data: encodeApprove(router, maxUint256) },
  // Swap rewards to USDC
  { to: router, data: encodeSwap(rewardToken, usdc, rewardAmount) },
  // Deposit USDC back into farm
  { to: farm, data: encodeDeposit(usdc, usdcAmount) }
]);

// Approve collection → List multiple NFTs
const listings = tokenIds.map(id => ({
  to: marketplace,
  data: encodeList(collection, id, price)
}));

await smartAccount.sendTransactions([
  { to: collection, data: encodeSetApprovalForAll(marketplace, true) },
  ...listings
]);

// Approve total → Transfer to all employees
const totalAmount = employees.reduce((sum, e) => sum + e.amount, 0n);

const transfers = employees.map(({ address, amount }) => ({
  to: paymentToken,
  data: encodeTransfer(address, amount)
}));

await smartAccount.sendTransactions([
  { to: paymentToken, data: encodeApprove(batchContract, totalAmount) },
  ...transfers
]);