Master Wallet Write Sign-Only
curl --request POST \
--url https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign \
--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"
]
}
]
}
'import requests
url = "https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign"
payload = { "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"]
}
] }
headers = {
"x-api-key": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {'x-api-key': '<api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({
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']
}
]
})
};
fetch('https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'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'
]
]
]
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"x-api-key: <api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign"
payload := strings.NewReader("{\n \"calls\": [\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n },\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n }\n ]\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("x-api-key", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign")
.header("x-api-key", "<api-key>")
.header("Content-Type", "application/json")
.body("{\n \"calls\": [\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n },\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n }\n ]\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"calls\": [\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n },\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n }\n ]\n}"
response = http.request(request)
puts response.read_body{
"data": {
"amlScreening": {},
"amount": null,
"amountPaid": null,
"amountUSD": "0.00",
"asset": null,
"assetSwept": null,
"assetSweptAmount": null,
"assetSweptAt": null,
"assetSweptGasFee": null,
"assetSweptHash": null,
"assetSweptRecipientAddress": null,
"assetSweptSenderAddress": null,
"blockHash": null,
"blockNumber": null,
"blockchain": {
"createdAt": "2024-05-27T14:31:14.966Z",
"derivationPath": "m/44'/60'/0'/0",
"id": "74733889-4ecd-403e-9840-94e87c043f24",
"isActive": true,
"isEvmCompatible": true,
"isL2": true,
"name": "base",
"slug": "base",
"symbol": "eth",
"tokenStandard": null,
"updatedAt": "2024-11-26T20:04:13.945Z"
},
"chainId": null,
"confirmations": null,
"confirmed": true,
"createdAt": "2025-08-11T22:21:56.077Z",
"currency": "USD",
"fee": null,
"feeHash": null,
"gasFee": null,
"gasPrice": null,
"gasUsed": null,
"hash": "0x229d811ef34a9f12454e89f12e06945dfc8122538a0af6369ec3f2a2f9aa8cbb",
"id": "fe2d8c39-a6ba-41cb-99e7-05c4dcee6c94",
"metadata": null,
"network": "testnet",
"note": null,
"rate": null,
"rateUSD": "0.00",
"reason": "{\"method\":\"transfer\",\"parameters\":[\"0x451dEFC27B45808078e875556AF06bCFdC697BA4\",\"10000\"],\"abi\":{\"constant\":false,\"inputs\":[{\"name\":\"_to\",\"type\":\"address\"},{\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"transfer\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"}}",
"recipientAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
"reference": "xvLz7CIFoD",
"senderAddress": "0x947514e4B803e312C312da0F1B41fEDdbe15ae7a",
"signedTransaction": "0xf8ab3e83124fc08301623d94036cbd53842c5426634e7929541ec2318f3dcf7e80b844a9059cbb000000000000000000000000451defc27b45808078e875556af06bcfdc697ba400000000000000000000000000000000000000000000000000000000000027108302948ca0c86783ba50374a959907d9174c2a0b5cd3a87d55336e6c9a6420fde0dd07303ea019a93dad742a9bed4c6d1f514f7fe26777e8f17fe090967a9719afddaa281d64",
"status": "SUCCESS",
"toAmount": null,
"toCurrency": null,
"tokenAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
"type": "SIGNED",
"updatedAt": "2025-08-11T22:21:56.077Z",
"wallet": {
"address": "0x947514e4B803e312C312da0F1B41fEDdbe15ae7a",
"configurations": null,
"createdAt": "2024-08-22T16:05:46.167Z",
"derivationPath": "m/44'/60'/0'/0/0",
"description": "This is Base wallet",
"id": "e17dea25-6c01-4b3a-a4ae-51f411bf69cd",
"isActive": true,
"name": "Base Wallet",
"network": "testnet",
"status": "ACTIVE",
"updatedAt": "2024-08-22T16:05:46.167Z"
}
},
"message": "Contract write signed successfully",
"statusCode": 200
}
Master Wallet Write Sign-Only
This API provides endpoints for interacting with smart contracts on the blockchain. It allows for executing contract functions without broadcasting
Request Body
The request body should be in raw format and include the following parameters:
| Parameter | Type | Required | Description |
|---|---|---|---|
| address | string | Yes | The address of the contract. |
| method | string | Yes | The method to be called on the contract. |
| parameters | array | Yes | An array of parameters to pass to the method. |
| abi | array | Yes | An array containing the ABI of the contract or method. |
POST
/
v1
/
wallets
/
{walletId}
/
contracts
/
write
/
sign
Master Wallet Write Sign-Only
curl --request POST \
--url https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign \
--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"
]
}
]
}
'import requests
url = "https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign"
payload = { "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"]
}
] }
headers = {
"x-api-key": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {'x-api-key': '<api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({
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']
}
]
})
};
fetch('https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'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'
]
]
]
]),
CURLOPT_HTTPHEADER => [
"Content-Type: application/json",
"x-api-key: <api-key>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign"
payload := strings.NewReader("{\n \"calls\": [\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n },\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n }\n ]\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("x-api-key", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign")
.header("x-api-key", "<api-key>")
.header("Content-Type", "application/json")
.body("{\n \"calls\": [\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n },\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n }\n ]\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.blockradar.co/v1/wallets/{walletId}/contracts/write/sign")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"calls\": [\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n },\n {\n \"abi\": [\n {\n \"constant\": false,\n \"inputs\": [\n {\n \"name\": \"_to\",\n \"type\": \"address\"\n },\n {\n \"name\": \"_value\",\n \"type\": \"uint256\"\n }\n ],\n \"name\": \"transfer\",\n \"outputs\": [],\n \"payable\": false,\n \"stateMutability\": \"nonpayable\",\n \"type\": \"function\"\n }\n ],\n \"address\": \"0x337610d27c682E347C9cD60BD4b3b107C9d34dDd\",\n \"method\": \"transfer\",\n \"parameters\": [\n \"0x2455eC6700092991Ce0782365A89d5Cd89c8Fa22\",\n \"10000\"\n ]\n }\n ]\n}"
response = http.request(request)
puts response.read_body{
"data": {
"amlScreening": {},
"amount": null,
"amountPaid": null,
"amountUSD": "0.00",
"asset": null,
"assetSwept": null,
"assetSweptAmount": null,
"assetSweptAt": null,
"assetSweptGasFee": null,
"assetSweptHash": null,
"assetSweptRecipientAddress": null,
"assetSweptSenderAddress": null,
"blockHash": null,
"blockNumber": null,
"blockchain": {
"createdAt": "2024-05-27T14:31:14.966Z",
"derivationPath": "m/44'/60'/0'/0",
"id": "74733889-4ecd-403e-9840-94e87c043f24",
"isActive": true,
"isEvmCompatible": true,
"isL2": true,
"name": "base",
"slug": "base",
"symbol": "eth",
"tokenStandard": null,
"updatedAt": "2024-11-26T20:04:13.945Z"
},
"chainId": null,
"confirmations": null,
"confirmed": true,
"createdAt": "2025-08-11T22:21:56.077Z",
"currency": "USD",
"fee": null,
"feeHash": null,
"gasFee": null,
"gasPrice": null,
"gasUsed": null,
"hash": "0x229d811ef34a9f12454e89f12e06945dfc8122538a0af6369ec3f2a2f9aa8cbb",
"id": "fe2d8c39-a6ba-41cb-99e7-05c4dcee6c94",
"metadata": null,
"network": "testnet",
"note": null,
"rate": null,
"rateUSD": "0.00",
"reason": "{\"method\":\"transfer\",\"parameters\":[\"0x451dEFC27B45808078e875556AF06bCFdC697BA4\",\"10000\"],\"abi\":{\"constant\":false,\"inputs\":[{\"name\":\"_to\",\"type\":\"address\"},{\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"transfer\",\"outputs\":[],\"payable\":false,\"stateMutability\":\"nonpayable\",\"type\":\"function\"}}",
"recipientAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
"reference": "xvLz7CIFoD",
"senderAddress": "0x947514e4B803e312C312da0F1B41fEDdbe15ae7a",
"signedTransaction": "0xf8ab3e83124fc08301623d94036cbd53842c5426634e7929541ec2318f3dcf7e80b844a9059cbb000000000000000000000000451defc27b45808078e875556af06bcfdc697ba400000000000000000000000000000000000000000000000000000000000027108302948ca0c86783ba50374a959907d9174c2a0b5cd3a87d55336e6c9a6420fde0dd07303ea019a93dad742a9bed4c6d1f514f7fe26777e8f17fe090967a9719afddaa281d64",
"status": "SUCCESS",
"toAmount": null,
"toCurrency": null,
"tokenAddress": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
"type": "SIGNED",
"updatedAt": "2025-08-11T22:21:56.077Z",
"wallet": {
"address": "0x947514e4B803e312C312da0F1B41fEDdbe15ae7a",
"configurations": null,
"createdAt": "2024-08-22T16:05:46.167Z",
"derivationPath": "m/44'/60'/0'/0/0",
"description": "This is Base wallet",
"id": "e17dea25-6c01-4b3a-a4ae-51f411bf69cd",
"isActive": true,
"name": "Base Wallet",
"network": "testnet",
"status": "ACTIVE",
"updatedAt": "2024-08-22T16:05:46.167Z"
}
},
"message": "Contract write signed successfully",
"statusCode": 200
}
Batch Operations
This endpoint supports batch operations, allowing you to sign multiple contract write operations without broadcasting them. This is useful for offline signing or preparing transactions for later submission.Batch Request Format
To sign multiple transactions, use thecalls array:
{
"calls": [
{
"address": "0xTokenContract...",
"method": "approve",
"parameters": ["0xSpender...", "1000000000000000000"],
"abi": [...],
"reference": "approve-tx"
},
{
"address": "0xProtocolContract...",
"method": "deposit",
"parameters": ["1000000000000000000"],
"abi": [...],
"reference": "deposit-tx"
}
],
"code": "123456"
}
Batch Response Format
Returns signed transactions without broadcasting:{
"message": "Batch contract write signed successfully",
"statusCode": 200,
"data": {
"success": [
{ "index": 0, "method": "approve", "signedTransaction": "0x..." },
{ "index": 1, "method": "deposit", "signedTransaction": "0x..." }
],
"errors": []
}
}
Validation Rules
| Rule | Value |
|---|---|
| Max batch size | 20 operations |
| Min batch size | 1 operation |
| 2FA required | Yes |
Use Cases
- Offline signing: Sign transactions for later broadcast
- Transaction preparation: Prepare multiple transactions in advance
- Multi-signature workflows: Generate signed payloads for multi-sig wallets
Authorizations
Path Parameters
Example:
"YOUR_WALLET_ID"
Body
application/json
Show child attributes
Show child attributes
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" ] } ]
⌘I