Step 3: Execute

With your signed payload ready, submit it to the /v1/execute endpoint. Biconomy’s MEE network handles all the blockchain complexity.

Execute Request

The request body is simple: the entire quote response with your signed payloads:

const result = await fetch('https://api.biconomy.io/v1/execute', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    ...quote,                        // Spread the entire quote
    payloadToSign: signedPayloads    // Replace with signed version
  })
}).then(r => r.json());

Complete Example

// 1. Get quote
const quote = await fetch('https://api.biconomy.io/v1/quote', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    mode: 'smart-account',
    ownerAddress: account.address,
    composeFlows: [{
      type: '/instructions/intent-simple',
      data: {
        srcChainId: 8453,
        dstChainId: 10,
        srcToken: USDC_BASE,
        dstToken: USDT_OPTIMISM,
        amount: '100000000',
        slippage: 0.01
      }
    }]
  })
}).then(r => r.json());

// 2. Sign
const payload = quote.payloadToSign[0];
const signature = await walletClient.signTypedData({
  ...payload.signablePayload,
  account
});

// 3. Execute
const result = await fetch('https://api.biconomy.io/v1/execute', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    ...quote,
    payloadToSign: [{ ...payload, signature }]
  })
}).then(r => r.json());

// 4. Check result
if (result.success) {
  console.log('Supertransaction hash:', result.supertxHash);
  console.log('Track at:', `https://meescan.biconomy.io/details/${result.supertxHash}`);
} else {
  console.error('Execution failed:', result.error);
}

Response

{
  "success": true,
  "supertxHash": "0x9a72f87a93c55d8f88e3f8c2a7b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2",
  "error": null
}

Field	Description
`success`	Whether execution was accepted
`supertxHash`	Unique identifier for tracking
`error`	Error message if failed

success: true means the transaction was accepted for execution, not that it’s complete. Use the supertxHash to track actual completion.

Tracking Execution

MEE Explorer

View real-time status at:

https://meescan.biconomy.io/details/{supertxHash}

Polling Status

async function waitForCompletion(supertxHash, apiKey, timeout = 120000) {
  const startTime = Date.now();
  
  while (Date.now() - startTime < timeout) {
    const status = await fetch(
      `https://network.biconomy.io/v1/explorer/${supertxHash}`,
      { headers: { 'Authorization': `Bearer ${apiKey}` } }
    ).then(r => r.json());
    
    if (status.status === 'SUCCESS') {
      return { success: true, data: status };
    }
    
    if (status.status === 'FAILED') {
      return { success: false, error: status.error };
    }
    
    // Still pending, wait and retry
    await new Promise(r => setTimeout(r, 3000));
  }
  
  throw new Error('Timeout waiting for execution');
}

// Usage
const completion = await waitForCompletion(result.supertxHash, API_KEY);
if (completion.success) {
  console.log('Transaction complete!');
}

Using AbstractJS SDK

If you’re using the SDK, there’s a built-in method:

import { createMeeClient } from '@biconomy/abstractjs';

const meeClient = createMeeClient({...});

const receipt = await meeClient.waitForSupertransactionReceipt({
  hash: result.supertxHash,
  timeout: 120000
});

console.log('Status:', receipt.status);

Error Handling

const result = await fetch('/v1/execute', {
  method: 'POST',
  body: JSON.stringify({ ...quote, payloadToSign: signedPayloads })
}).then(async r => {
  if (!r.ok) {
    const error = await r.json();
    throw new Error(error.message || 'Execution failed');
  }
  return r.json();
});

if (!result.success) {
  // Handle specific errors
  if (result.error?.includes('insufficient balance')) {
    console.log('User needs more tokens');
  } else if (result.error?.includes('signature')) {
    console.log('Signature invalid or expired');
  } else {
    console.log('Execution failed:', result.error);
  }
}

Common Issues

Invalid signature

Make sure you’re signing the exact payload from the quote
Check you’re using the correct signing method for the quoteType
Quotes expire—get a fresh one if too much time has passed

Insufficient balance

Verify user has enough tokens for the operation
Remember fees are deducted from balance too
For EOA mode, check fundingTokens matches actual balance

Quote expired

Quotes are valid for ~30 seconds
Get a new quote if user takes too long to sign
Consider showing a countdown in your UI

Execution failed after success: true

success: true only means the tx was accepted
Check MEE Explorer for actual execution status
On-chain conditions may have changed (slippage, liquidity)

Full Flow Summary

// Complete implementation
async function executeSupertransaction(composeFlows, account, walletClient) {
  // 1. Quote
  const quote = await fetch('https://api.biconomy.io/v1/quote', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json', 'X-API-Key': API_KEY },
    body: JSON.stringify({
      mode: 'smart-account',
      ownerAddress: account.address,
      composeFlows
    })
  }).then(r => r.json());
  
  // 2. Sign
  const payload = quote.payloadToSign[0];
  const signature = await walletClient.signTypedData({
    ...payload.signablePayload,
    account
  });
  
  // 3. Execute
  const result = await fetch('https://api.biconomy.io/v1/execute', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      ...quote,
      payloadToSign: [{ ...payload, signature }]
    })
  }).then(r => r.json());
  
  if (!result.success) {
    throw new Error(result.error);
  }
  
  // 4. Wait for completion
  const completion = await waitForCompletion(result.supertxHash, API_KEY);
  
  return {
    hash: result.supertxHash,
    status: completion.success ? 'complete' : 'failed'
  };
}

Next Steps

Gasless Swaps

Build gasless trading experiences

Cross-Chain Swaps

Multi-chain swap tutorials

Full API Reference

Complete endpoint documentation

DeFi Examples

Lending, staking, and more

Welcome

ERC-8211 Smart Batching

Supertransaction API

AbstractJS SDK

Execute Request

Complete Example

Response

Tracking Execution

MEE Explorer

Polling Status

Using AbstractJS SDK

Error Handling

Common Issues

Full Flow Summary

Next Steps

Gasless Swaps

Cross-Chain Swaps

Full API Reference

DeFi Examples

​Execute Request

​Complete Example

​Response

​Tracking Execution

​MEE Explorer

​Polling Status

​Using AbstractJS SDK

​Error Handling

​Common Issues

​Full Flow Summary

​Next Steps

Gasless Swaps

Cross-Chain Swaps

Full API Reference

DeFi Examples

Execute Request

Complete Example

Response

Tracking Execution

MEE Explorer

Polling Status

Using AbstractJS SDK

Error Handling

Common Issues

Full Flow Summary

Next Steps