Withdraw Stablecoins

In a nutshell
The Blockradar Withdraw API allows you to send stablecoin assets from your wallets to external blockchain addresses. It supports single withdrawals, batch withdrawals to multiple recipients, and provides fee estimation before execution.

Prerequisites

Before using the Withdraw API, ensure you have:

API Key

Get your API key from the Blockradar Dashboard. Navigate to Developers to generate one.

Wallet Created

Create a wallet via the Create Wallet API or dashboard. You’ll need the walletId for withdrawal operations.

Asset ID

Get the assetId for the token you want to withdraw from Assets in the dashboard or via the Get Assets API.

Sufficient Balance

Ensure your wallet has enough balance of the asset to withdraw, plus native currency (ETH, BNB, MATIC, etc.) to cover network fees.

How It Works

The Withdraw API sends stablecoin assets from your Blockradar wallet to any external blockchain address:

Single Withdrawal

Send assets to one recipient address with a single API call.

Batch Withdrawal

Send assets to multiple recipients in a single API call, reducing overhead and simplifying bulk payouts.

Fee Estimation

Calculate network fees before execution to ensure sufficient balance and display costs to users.

Sign-Only Mode

Sign transactions without broadcasting for advanced use cases like offline signing or custom submission.

Master Wallet vs Child Address

The Withdraw API is available at two levels:

Master Wallet

Withdraw directly from your master wallet. Ideal for treasury operations and centralized fund management.

Child Address

Withdraw from individual child addresses. Perfect for user-specific operations and segregated fund management.

Endpoints

Operation	Master Wallet	Child Address
Withdraw	`POST /v1/wallets/{walletId}/withdraw`	`POST /v1/wallets/{walletId}/addresses/{addressId}/withdraw`
Network Fee	`POST /v1/wallets/{walletId}/withdraw/network-fee`	`POST /v1/wallets/{walletId}/addresses/{addressId}/withdraw/network-fee`
Sign-Only	`POST /v1/wallets/{walletId}/withdraw/sign`	`POST /v1/wallets/{walletId}/addresses/{addressId}/withdraw/sign`

Single Withdrawal

Send assets to a single recipient address.

Request Parameters

Parameter	Type	Required	Description
`assetId`	string	Yes*	The UUID of the asset to withdraw. Required if `assets` array is not provided.
`address`	string	Yes*	The destination wallet address. Required if `assets` array is not provided.
`amount`	string	Yes*	The withdrawal amount. Must be greater than 0. Required if `assets` array is not provided.
`reference`	string	No	Your internal tracking ID for the withdrawal.
`note`	string	No	A short message or internal remark. Not visible on-chain.
`metadata`	object	No	Custom key-value pairs for additional transaction details.

Parameters marked with * are required for single withdrawals but are not needed if you’re using the assets array for batch withdrawals.

Single Withdrawal Example

curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{walletId}/withdraw \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
    "assetId": "asset-uuid-here",
    "address": "0xRecipientAddress...",
    "amount": "100",
    "reference": "payout-12345",
    "note": "Monthly payout",
    "metadata": {
      "userId": "user_abc123",
      "payoutType": "salary"
    }
  }'

const withdrawal = await fetch(
  `https://api.blockradar.co/v1/wallets/${walletId}/withdraw`,
  {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': apiKey
    },
    body: JSON.stringify({
      assetId: 'asset-uuid-here',
      address: '0xRecipientAddress...',
      amount: '100',
      reference: 'payout-12345',
      note: 'Monthly payout',
      metadata: {
        userId: 'user_abc123',
        payoutType: 'salary'
      }
    })
  }
).then(r => r.json());

console.log('Withdrawal initiated:', withdrawal.data);

Single Withdrawal Response

{
  "message": "Withdrawal initiated successfully",
  "statusCode": 200,
  "data": {
    "id": "tx-uuid-123",
    "hash": "0xabc123...",
    "status": "PENDING",
    "amount": "100",
    "recipientAddress": "0xRecipientAddress...",
    "reference": "payout-12345",
    "note": "Monthly payout",
    "metadata": {
      "userId": "user_abc123",
      "payoutType": "salary"
    },
    "createdAt": "2024-01-15T10:30:00Z"
  }
}

Batch Withdrawals

Send assets to multiple recipients in a single API call. Batch withdrawals are executed sequentially, and each withdrawal is processed as a separate blockchain transaction.

When to Use Batch Withdrawals

Bulk payouts: Pay multiple employees, vendors, or partners at once
Distributions: Send assets to multiple addresses
Multi-recipient transfers: Send different amounts to different addresses
Operational efficiency: Reduce API calls and simplify payout logic

Batch Request Parameters

For batch withdrawals, use the assets array instead of individual parameters:

Parameter	Type	Required	Description
`assets`	array	Yes	Array of withdrawal objects (max 20 per batch)

Each item in the assets array:

Field	Type	Required	Description
`id`	string	Yes	The UUID of the asset to withdraw
`address`	string	Yes	The destination wallet address
`amount`	string	Yes	The withdrawal amount. Must be greater than 0.
`reference`	string	No	Optional reference note for this withdrawal
`note`	string	No	A short message or internal remark. Not visible on-chain.
`metadata`	object	No	Custom key-value pairs for additional transaction details.

Batch Withdrawal Example

curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{walletId}/withdraw \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
    "assets": [
      {
        "id": "asset-uuid-usdc",
        "address": "0xRecipient1...",
        "amount": "100",
        "reference": "payout-001",
        "note": "January salary"
      },
      {
        "id": "asset-uuid-usdc",
        "address": "0xRecipient2...",
        "amount": "150",
        "reference": "payout-002",
        "note": "January salary"
      },
      {
        "id": "asset-uuid-usdt",
        "address": "0xRecipient3...",
        "amount": "200",
        "reference": "payout-003",
        "note": "Vendor payment"
      }
    ]
  }'

const batchWithdrawal = await fetch(
  `https://api.blockradar.co/v1/wallets/${walletId}/withdraw`,
  {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': apiKey
    },
    body: JSON.stringify({
      assets: [
        {
          id: 'asset-uuid-usdc',
          address: '0xRecipient1...',
          amount: '100',
          reference: 'payout-001',
          note: 'January salary'
        },
        {
          id: 'asset-uuid-usdc',
          address: '0xRecipient2...',
          amount: '150',
          reference: 'payout-002',
          note: 'January salary'
        },
        {
          id: 'asset-uuid-usdt',
          address: '0xRecipient3...',
          amount: '200',
          reference: 'payout-003',
          note: 'Vendor payment'
        }
      ]
    })
  }
).then(r => r.json());

console.log('Batch withdrawal result:', batchWithdrawal.data);

Batch Withdrawal Response

{
  "message": "Batch withdrawal initiated successfully",
  "statusCode": 200,
  "data": {
    "success": [
      {
        "index": 0,
        "id": "tx-uuid-1",
        "hash": "0xabc...",
        "status": "PENDING",
        "amount": "100",
        "recipientAddress": "0xRecipient1...",
        "reference": "payout-001"
      },
      {
        "index": 1,
        "id": "tx-uuid-2",
        "hash": "0xdef...",
        "status": "PENDING",
        "amount": "150",
        "recipientAddress": "0xRecipient2...",
        "reference": "payout-002"
      },
      {
        "index": 2,
        "id": "tx-uuid-3",
        "hash": "0xghi...",
        "status": "PENDING",
        "amount": "200",
        "recipientAddress": "0xRecipient3...",
        "reference": "payout-003"
      }
    ],
    "errors": []
  }
}

Handling Partial Failures

Batch withdrawals support partial success. If some withdrawals fail, others will still execute:

const result = await batchWithdrawal.json();

// Process successful withdrawals
result.data.success.forEach(tx => {
  console.log(`✓ ${tx.reference}: ${tx.hash}`);
});

// Handle failed withdrawals
result.data.errors.forEach(error => {
  console.error(`✗ Index ${error.index}: ${error.error}`);
  // Retry logic or error reporting here
});

Batch Withdrawal Rules

Rule	Value
Maximum batch size	20 withdrawals per request
Minimum batch size	1 withdrawal
Execution order	Sequential
Error handling	Partial success (failures don’t stop subsequent withdrawals)

Estimating Network Fees

Always estimate fees before executing withdrawals to ensure sufficient native token balance and to display accurate costs to users.

Single Fee Estimation

curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{walletId}/withdraw/network-fee \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
    "assetId": "asset-uuid-here",
    "address": "0xRecipientAddress...",
    "amount": "100"
  }'

const fee = await fetch(
  `https://api.blockradar.co/v1/wallets/${walletId}/withdraw/network-fee`,
  {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': apiKey
    },
    body: JSON.stringify({
      assetId: 'asset-uuid-here',
      address: '0xRecipientAddress...',
      amount: '100'
    })
  }
).then(r => r.json());

console.log('Network fee:', fee.data.networkFee);
console.log('Fee in USD:', fee.data.networkFeeInUSD);

Single Fee Response

{
  "message": "Network fee fetched successfully",
  "statusCode": 200,
  "data": {
    "networkFee": "0.00001247904",
    "networkFeeInUSD": "0.01",
    "transactionFee": "0",
    "nativeBalance": "0.5",
    "nativeBalanceInUSD": "450.00",
    "estimatedArrivalTime": 30
  }
}

Batch Fee Estimation

Estimate fees for multiple withdrawals at once:

curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{walletId}/withdraw/network-fee \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
    "assets": [
      {
        "id": "asset-uuid-1",
        "address": "0xRecipient1...",
        "amount": "100"
      },
      {
        "id": "asset-uuid-2",
        "address": "0xRecipient2...",
        "amount": "50"
      }
    ]
  }'

const batchFee = await fetch(
  `https://api.blockradar.co/v1/wallets/${walletId}/withdraw/network-fee`,
  {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': apiKey
    },
    body: JSON.stringify({
      assets: [
        {
          id: 'asset-uuid-1',
          address: '0xRecipient1...',
          amount: '100'
        },
        {
          id: 'asset-uuid-2',
          address: '0xRecipient2...',
          amount: '50'
        }
      ]
    })
  }
).then(r => r.json());

console.log('Total network fee:', batchFee.data.totalNetworkFee);
console.log('Total fee in USD:', batchFee.data.totalNetworkFeeInUSD);

Batch Fee Response

{
  "message": "Network fee fetched successfully",
  "statusCode": 200,
  "data": {
    "fees": [
      {
        "index": 0,
        "assetId": "asset-uuid-1",
        "address": "0xRecipient1...",
        "amount": "100",
        "networkFee": "0.00001247904",
        "transactionFee": "0",
        "estimatedArrivalTime": 30
      },
      {
        "index": 1,
        "assetId": "asset-uuid-2",
        "address": "0xRecipient2...",
        "amount": "50",
        "networkFee": "0.00000504",
        "transactionFee": "0",
        "estimatedArrivalTime": 30
      }
    ],
    "totalNetworkFee": "0.00001751904",
    "totalNetworkFeeInUSD": "0.02",
    "totalTransactionFee": "0",
    "nativeBalance": "0.073690520542044578",
    "nativeBalanceInUSD": "66.54",
    "estimatedArrivalTime": 60,
    "errors": []
  }
}

Fee Response Fields

Field	Description
`networkFee`	Gas fee in native token units (single withdrawal)
`networkFeeInUSD`	Gas fee converted to USD (single withdrawal)
`fees`	Array of individual fee estimates (batch withdrawal)
`totalNetworkFee`	Sum of all network fees (batch withdrawal)
`totalNetworkFeeInUSD`	Total network fee in USD (batch withdrawal)
`transactionFee`	Platform transaction fee (if applicable)
`nativeBalance`	Current native token balance
`nativeBalanceInUSD`	Native token balance in USD
`estimatedArrivalTime`	Expected confirmation time in seconds
`errors`	Array of any failed estimations (batch withdrawal)

Sign-Only Mode

Sign transactions without broadcasting them to the blockchain. Useful for:

Offline signing: Prepare transactions for later submission
Multi-signature workflows: Collect signatures before submission
Transaction inspection: Review transaction details before broadcasting

Sign-Only Example

curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{walletId}/withdraw/sign \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
    "assetId": "asset-uuid-here",
    "address": "0xRecipientAddress...",
    "amount": "100"
  }'

const signedTx = await fetch(
  `https://api.blockradar.co/v1/wallets/${walletId}/withdraw/sign`,
  {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': apiKey
    },
    body: JSON.stringify({
      assetId: 'asset-uuid-here',
      address: '0xRecipientAddress...',
      amount: '100'
    })
  }
).then(r => r.json());

console.log('Signed transaction:', signedTx.data.signedTransaction);

Sign-Only Response

{
  "message": "Transaction signed successfully",
  "statusCode": 200,
  "data": {
    "id": "tx-uuid-123",
    "signedTransaction": "0xf86c...",
    "status": "SIGNED",
    "amount": "100",
    "recipientAddress": "0xRecipientAddress...",
    "createdAt": "2024-01-15T10:30:00Z"
  }
}

Child Address Withdrawals

Withdraw from individual child addresses instead of the master wallet:

curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{walletId}/addresses/{addressId}/withdraw \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '{
    "assetId": "asset-uuid-here",
    "address": "0xRecipientAddress...",
    "amount": "50",
    "reference": "user-withdrawal-123"
  }'

const childWithdrawal = await fetch(
  `https://api.blockradar.co/v1/wallets/${walletId}/addresses/${addressId}/withdraw`,
  {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'x-api-key': apiKey
    },
    body: JSON.stringify({
      assetId: 'asset-uuid-here',
      address: '0xRecipientAddress...',
      amount: '50',
      reference: 'user-withdrawal-123'
    })
  }
).then(r => r.json());

console.log('Child address withdrawal:', childWithdrawal.data);

Child address withdrawals also support batch operations using the assets array, following the same format as master wallet batch withdrawals.

Webhook Events

Monitor withdrawal completion through webhooks:

Event	Description
`withdraw.success`	Withdrawal completed and confirmed on the blockchain
`withdraw.failed`	Withdrawal failed to execute
`withdraw.cancelled`	Withdrawal was cancelled before completion

Webhook Payload

{
  "event": "withdraw.success",
  "data": {
    "id": "081d6315-159f-4c38-b02a-c4708836c5bd",
    "reference": "payout-12345",
    "senderAddress": "0x947514e4B803e312C312da0F1B41fEDdbe15ae7a",
    "recipientAddress": "0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22",
    "amount": "100",
    "amountPaid": "100",
    "fee": null,
    "currency": "USD",
    "blockNumber": 6928833,
    "hash": "0x5fcb7dd11cbb5a6d64da08cf7e0d63c1a1e7b9d1b89e3e8d1c6a5f4b3a2c1d0e",
    "status": "SUCCESS",
    "type": "WITHDRAW",
    "note": "Monthly payout",
    "asset": {
      "id": "asset-uuid",
      "name": "USD Coin",
      "symbol": "USDC",
      "decimals": 6
    },
    "wallet": {
      "id": "wallet-uuid",
      "name": "Main Treasury"
    },
    "blockchain": {
      "id": "blockchain-uuid",
      "name": "ethereum",
      "network": "mainnet"
    },
    "metadata": {
      "userId": "user_abc123",
      "payoutType": "salary"
    },
    "createdAt": "2024-01-15T10:30:00Z",
    "updatedAt": "2024-01-15T10:31:00Z"
  }
}

Complete Flow Example

Here’s a full implementation showing the fee estimation → user confirmation → withdrawal flow:

async function processWithdrawal(walletId, assetId, recipientAddress, amount) {
  const apiKey = process.env.BLOCKRADAR_API_KEY;
  const baseUrl = 'https://api.blockradar.co/v1';

  // Step 1: Estimate network fee
  const feeResponse = await fetch(
    `${baseUrl}/wallets/${walletId}/withdraw/network-fee`,
    {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-api-key': apiKey
      },
      body: JSON.stringify({
        assetId,
        address: recipientAddress,
        amount
      })
    }
  ).then(r => r.json());

  // Step 2: Check if we have enough native balance for gas
  const fee = feeResponse.data;
  if (parseFloat(fee.nativeBalance) < parseFloat(fee.networkFee)) {
    throw new Error(`Insufficient gas: need ${fee.networkFee}, have ${fee.nativeBalance}`);
  }

  // Step 3: Display fee to user (in your UI)
  console.log(`Network fee: ${fee.networkFee} (≈$${fee.networkFeeInUSD})`);
  console.log(`Estimated time: ${fee.estimatedArrivalTime}s`);

  // Step 4: Execute withdrawal (after user confirmation)
  const withdrawal = await fetch(
    `${baseUrl}/wallets/${walletId}/withdraw`,
    {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'x-api-key': apiKey
      },
      body: JSON.stringify({
        assetId,
        address: recipientAddress,
        amount,
        reference: `withdraw-${Date.now()}`
      })
    }
  ).then(r => r.json());

  console.log('Withdrawal initiated:', withdrawal.data.id);
  console.log('Transaction hash:', withdrawal.data.hash);

  // Step 5: Listen for webhook to confirm completion
  return withdrawal.data;
}

// Usage
processWithdrawal(
  'wallet-uuid',
  'asset-uuid-usdc',
  '0xRecipientAddress...',
  '100'
);

Error Responses

Insufficient Balance

{
  "message": "Insufficient balance for withdrawal",
  "statusCode": 400,
  "error": "INSUFFICIENT_BALANCE",
  "data": {
    "required": "100",
    "available": "50.25",
    "asset": "USDC"
  }
}

Insufficient Gas

{
  "message": "Insufficient native token balance for gas",
  "statusCode": 400,
  "error": "INSUFFICIENT_GAS",
  "data": {
    "required": "0.005",
    "available": "0.001",
    "token": "ETH"
  }
}

Invalid Address

{
  "message": "Invalid recipient address",
  "statusCode": 400,
  "error": "INVALID_ADDRESS",
  "data": {
    "address": "invalid_address_here"
  }
}

Asset Not Found

{
  "message": "Asset not found",
  "statusCode": 404,
  "error": "ASSET_NOT_FOUND",
  "data": {
    "assetId": "invalid-asset-uuid"
  }
}

Amount Too Low

{
  "message": "Amount must be greater than 0",
  "statusCode": 400,
  "error": "INVALID_AMOUNT",
  "data": {
    "amount": "0"
  }
}

Batch Size Exceeded

{
  "message": "Batch size exceeds maximum limit",
  "statusCode": 400,
  "error": "BATCH_SIZE_EXCEEDED",
  "data": {
    "maximum": 20,
    "provided": 25
  }
}

Best Practices

Security

Validate addresses: Always verify recipient addresses before initiating withdrawals
Use references: Track withdrawals with unique reference IDs for reconciliation
Implement webhooks: Listen for withdraw.success and withdraw.failed events to confirm status
Check AML: Blockradar automatically screens addresses—review any flagged transactions

Fee Management

Estimate before execution: Always call the network-fee endpoint before withdrawals
Monitor native balance: Ensure sufficient ETH/BNB/MATIC for gas fees
Use batch for efficiency: Group multiple withdrawals to reduce API calls and operational overhead

Error Handling

Handle partial failures: In batch withdrawals, check both success and errors arrays
Implement retries: Use exponential backoff for transient failures
Log all transactions: Store transaction IDs and hashes for debugging and reconciliation

Performance

Use appropriate batch sizes: Larger batches reduce API calls but increase individual request time
Cache asset IDs: Store asset IDs locally to avoid repeated lookups
Implement rate limiting: Respect API rate limits to avoid throttling

API Reference

Master Wallet Endpoints

Endpoint	Description
Withdraw	Execute single or batch withdrawal
Network Fee	Estimate withdrawal fees
Sign-Only	Sign without broadcasting

Child Address Endpoints

Endpoint	Description
Withdraw	Execute single or batch withdrawal
Network Fee	Estimate withdrawal fees
Sign-Only	Sign without broadcasting

Support

Email: [email protected]
Documentation: API Reference
Webhooks Guide: Webhooks

The Withdraw API provides a flexible interface for sending stablecoin assets to external addresses. Start with single withdrawals and fee estimation, then incorporate batch operations for bulk payouts as your needs grow.

​Prerequisites

​How It Works

Single Withdrawal

Batch Withdrawal

Fee Estimation

Sign-Only Mode

​Master Wallet vs Child Address

Master Wallet

Child Address

​Endpoints

​Single Withdrawal

​Request Parameters

​Single Withdrawal Example

​Single Withdrawal Response

​Batch Withdrawals

​When to Use Batch Withdrawals

​Batch Request Parameters

​Batch Withdrawal Example

​Batch Withdrawal Response

​Handling Partial Failures

​Batch Withdrawal Rules

​Estimating Network Fees

​Single Fee Estimation

​Single Fee Response

​Batch Fee Estimation

​Batch Fee Response

​Fee Response Fields

​Sign-Only Mode

​Sign-Only Example

​Sign-Only Response

​Child Address Withdrawals

​Webhook Events

​Webhook Payload

​Complete Flow Example

​Error Responses

​Best Practices

​Security

​Fee Management

​Error Handling

​Performance

​API Reference

​Master Wallet Endpoints

​Child Address Endpoints

​Support

Prerequisites

How It Works

Master Wallet vs Child Address

Endpoints

Single Withdrawal

Request Parameters

Single Withdrawal Example

Single Withdrawal Response

Batch Withdrawals

When to Use Batch Withdrawals

Batch Request Parameters

Batch Withdrawal Example

Batch Withdrawal Response

Handling Partial Failures

Batch Withdrawal Rules

Estimating Network Fees

Single Fee Estimation

Single Fee Response

Batch Fee Estimation

Batch Fee Response

Fee Response Fields

Sign-Only Mode

Sign-Only Example

Sign-Only Response

Child Address Withdrawals

Webhook Events

Webhook Payload

Complete Flow Example

Error Responses

Best Practices

Security

Fee Management

Error Handling

Performance

API Reference

Master Wallet Endpoints

Child Address Endpoints

Support