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POST
/
v1
/
wallets
/
{walletId}
/
addresses
/
{addressId}
/
contracts
/
write
Child Address Write
curl --request POST \
  --url https://api.blockradar.co/v1/wallets/{walletId}/addresses/{addressId}/contracts/write \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "calls": [
    {
      "abi": [
        {
          "constant": false,
          "inputs": [
            {
              "name": "_to",
              "type": "address"
            },
            {
              "name": "_value",
              "type": "uint256"
            }
          ],
          "name": "transfer",
          "outputs": [],
          "payable": false,
          "stateMutability": "nonpayable",
          "type": "function"
        }
      ],
      "address": "0x337610d27c682E347C9cD60BD4b3b107C9d34dDd",
      "method": "transfer",
      "parameters": [
        "0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22",
        "10000"
      ]
    },
    {
      "abi": [
        {
          "constant": false,
          "inputs": [
            {
              "name": "_to",
              "type": "address"
            },
            {
              "name": "_value",
              "type": "uint256"
            }
          ],
          "name": "transfer",
          "outputs": [],
          "payable": false,
          "stateMutability": "nonpayable",
          "type": "function"
        }
      ],
      "address": "0x337610d27c682E347C9cD60BD4b3b107C9d34dDd",
      "method": "transfer",
      "parameters": [
        "0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22",
        "10000"
      ]
    }
  ]
}
'
{
  "data": {
    "amlScreening": null,
    "amountPaid": null,
    "assetSwept": null,
    "assetSweptAmount": null,
    "assetSweptAt": null,
    "assetSweptGasFee": null,
    "assetSweptHash": null,
    "assetSweptRecipientAddress": null,
    "assetSweptResponse": null,
    "assetSweptSenderAddress": null,
    "blockHash": null,
    "blockNumber": null,
    "blockchain": {
      "createdAt": "2024-05-14T17:53:33.106Z",
      "derivationPath": "m/44'/60'/0'/0",
      "id": "b80d3d5e-16f1-4d99-be5e-6dfcd27f89aa",
      "isActive": true,
      "isEvmCompatible": true,
      "isL2": false,
      "logoUrl": "https://res.cloudinary.com/blockradar/image/upload/v1716800080/crypto-assets/bnb-bnb-logo_e4qdyk.png",
      "name": "BNB smart chain",
      "slug": "bnb-smart-chain",
      "symbol": "bnb",
      "tokenStandard": "BEP20",
      "updatedAt": "2024-11-26T19:04:13.941Z"
    },
    "chainId": null,
    "confirmations": null,
    "confirmed": false,
    "createdAt": "2025-01-15T21:17:24.013Z",
    "currency": null,
    "fee": null,
    "feeMetadata": null,
    "gasFee": null,
    "gasPrice": null,
    "gasUsed": null,
    "hash": null,
    "id": "42e94af1-1b8c-47fd-9250-276a3c8a3a71",
    "metadata": null,
    "network": "testnet",
    "note": null,
    "reason": "{\"method\":\"transfer\",\"parameters\":[\"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\"100000\"],\"abi\":{\"constant\":false,\"inputs\":[{\"name\":\"_to\",\"type\":\"address\"},{\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"transfer\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"}}",
    "recipientAddress": "0x337610d27c682E347C9cD60BD4b3b107C9d34dDd",
    "response": null,
    "senderAddress": "0x947514e4B803e312C312da0F1B41fEDdbe15ae7a",
    "status": "PENDING",
    "tokenAddress": "0x337610d27c682E347C9cD60BD4b3b107C9d34dDd",
    "type": "CUSTOM_SMART_CONTRACT",
    "updatedAt": "2025-01-15T21:17:24.013Z",
    "wallet": {
      "address": "0x947514e4B803e312C312da0F1B41fEDdbe15ae7a",
      "business": {
        "id": "4b96c271-35eb-45e8-b558-6a53f95df601",
        "name": "Test One Inc"
      },
      "createdAt": "2024-08-22T15:29:11.387Z",
      "derivationPath": "m/44'/60'/0'/0/0",
      "description": "This is BNB smart chain testnet master wallet",
      "id": "4465468a-3c36-4536-918a-91d689e18a74",
      "isActive": true,
      "name": "BNB smart chain Master Wallet",
      "network": "testnet",
      "status": "ACTIVE",
      "updatedAt": "2024-10-30T13:11:56.221Z"
    }
  },
  "message": "Contract write initiated successfully",
  "statusCode": 200
}

Documentation Index

Fetch the complete documentation index at: https://docs.blockradar.co/llms.txt

Use this file to discover all available pages before exploring further.

​
Batch Operations

This endpoint supports batch operations, allowing you to execute multiple contract write operations from a specific child address in a single API call.

​
Batch Request Format

To execute multiple writes, use the calls array: 
{
  "calls": [
    {
      "address": "0xTokenContract...",
      "method": "approve",
      "parameters": ["0xSpender...", "1000000000000000000"],
      "abi": [...],
      "reference": "approve-tx",
      "metadata": { "step": "approval" }
    },
    {
      "address": "0xProtocolContract...",
      "method": "deposit",
      "parameters": ["1000000000000000000"],
      "abi": [...],
      "reference": "deposit-tx",
      "metadata": { "step": "deposit" }
    }
  ],
  "code": "123456"
}

​
Batch Response Format

Batch responses include success and errors arrays: 
{
  "message": "Batch contract write initiated successfully",
  "statusCode": 200,
  "data": {
    "success": [
      { "id": "tx-uuid-1", "hash": "0x...", "status": "pending", "reference": "approve-tx" },
      { "id": "tx-uuid-2", "hash": "0x...", "status": "pending", "reference": "deposit-tx" }
    ],
    "errors": []
  }
}

​
Batch Call Item Schema

ParameterTypeRequiredDescription
addressstringYesSmart contract address
methodstringYesMethod name to call
parametersarrayNoMethod parameters (defaults to [])
abiarrayYesContract ABI
referencestringNoCustom reference for tracking
metadataobjectNoCustom metadata

​
Error Handling

Batch operations use a partial success pattern:
  • Operations are executed sequentially
  • A failure in one operation does not stop subsequent operations
  • Check both success and errors arrays to determine overall result

​
Validation Rules

RuleValue
Max batch size20 operations
Min batch size1 operation
2FA requiredYes

​
Use Cases

  • Approve + Deposit: Approve token spending then deposit in one call
  • Multi-step transactions: Chain multiple contract calls for DeFi operations
  • Protocol interactions: Execute complex protocol interactions atomically

Authorizations

​
x-api-key
string
header
required

Path Parameters

​
walletId
string
required
Example:

"YOUR_WALLET_ID"

​
addressId
string
required
Example:

"ADDRESS_ID"

Body

application/json
​
calls
object[]
Example:
[
  {
    "abi": [
      {
        "constant": false,
        "inputs": [
          { "name": "_to", "type": "address" },
          { "name": "_value", "type": "uint256" }
        ],
        "name": "transfer",
        "outputs": [],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "function"
      }
    ],
    "address": "0x337610d27c682E347C9cD60BD4b3b107C9d34dDd",
    "method": "transfer",
    "parameters": [
      "0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22",
      "10000"
    ]
  },
  {
    "abi": [
      {
        "constant": false,
        "inputs": [
          { "name": "_to", "type": "address" },
          { "name": "_value", "type": "uint256" }
        ],
        "name": "transfer",
        "outputs": [],
        "payable": false,
        "stateMutability": "nonpayable",
        "type": "function"
      }
    ],
    "address": "0x337610d27c682E347C9cD60BD4b3b107C9d34dDd",
    "method": "transfer",
    "parameters": [
      "0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22",
      "10000"
    ]
  }
]

Response

200 - application/json

Ethereum / Tron / Ethereum (Batch) / Tron (Batch)

​
data
object
​
message
string
Example:

"Contract write initiated successfully"

​
statusCode
number
Example:

200