Quickstart

This guide walks you through creating a wallet, signing a message, and sending your first transaction using the MoonKey REST API.

Prerequisites

Before you begin, make sure you have:

Completed the REST API setup guide
Your MoonKey API key (test or live)
A test user ID (or follow step 0 to create one)

All examples in this guide use test API keys. Replace sk_test_your_api_key_here with your actual API key.

Create a User (Optional)

If you want your wallet to be owned by a specific user, first create a user account:

curl -X POST "https://api.moonkey.fun/v1/auth/users/create" \
  -H "Authorization: Bearer sk_test_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "user@example.com"
  }'

const apiKey = process.env.MOONKEY_SECRET_KEY;

const response = await fetch('https://api.moonkey.fun/v1/auth/users/create', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${apiKey}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    email: 'user@example.com'
  })
});

const user = await response.json();
console.log('User created:', user.id);

import requests
import os

api_key = os.environ.get('MOONKEY_SECRET_KEY')

url = "https://api.moonkey.fun/v1/auth/users/create"
headers = {
    "Authorization": f"Bearer {api_key}",
    "Content-Type": "application/json"
}
payload = {
    "email": "user@example.com"
}

response = requests.post(url, json=payload, headers=headers)
user = response.json()
print(f"User created: {user['id']}")

The response will include the user ID:

{
  "id": "user_2Cu2uVhYy0OVgRcO913OsqIVaPI",
  "app_id": "app_24ydphdixx2ydhF0E5WUFUKWNqi",
  "email": "user@example.com",
  "created_at": 1659638371,
  "updated_at": 1659638371
}

Save the id field from the response. You’ll need it in the next step to create a wallet for this user.

1. Create a Wallet

Let’s create an Ethereum wallet for your user:

curl -X POST "https://api.moonkey.fun/v1/wallets/create" \
  -H "Authorization: Bearer sk_test_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "wallet_type": "ethereum",
    "user_id": "user_2Cu2uVhYy0OVgRcO913OsqIVaPI"
  }'

const apiKey = process.env.MOONKEY_SECRET_KEY;
const userId = 'user_2Cu2uVhYy0OVgRcO913OsqIVaPI';

const response = await fetch('https://api.moonkey.fun/v1/wallets/create', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${apiKey}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    wallet_type: 'ethereum',
    user_id: userId
  })
});

const wallet = await response.json();
console.log('Wallet created:', wallet.public_address);

import requests
import os

api_key = os.environ.get('MOONKEY_SECRET_KEY')
user_id = 'user_2Cu2uVhYy0OVgRcO913OsqIVaPI'

url = "https://api.moonkey.fun/v1/wallets/create"
headers = {
    "Authorization": f"Bearer {api_key}",
    "Content-Type": "application/json"
}
payload = {
    "wallet_type": "ethereum",
    "user_id": user_id
}

response = requests.post(url, json=payload, headers=headers)
wallet = response.json()
print(f"Wallet created: {wallet['public_address']}")

The response will include the wallet ID and public address:

{
  "id": "wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK",
  "app_id": "app_24ydphdixx2ydhF0E5WUFUKWNqi",
  "user_id": "user_2Cu2uVhYy0OVgRcO913OsqIVaPI",
  "public_address": "0xf1347fd847f19c250b4c9678ecaa27b0f6ce8804",
  "wallet_type": "ethereum",
  "verified": true,
  "is_default": true,
  "is_read_only": false,
  "is_imported": false,
  "created_at": 1659638371,
  "updated_at": 1659638371
}

If a wallet of the same type already exists for the user, MoonKey will return the existing wallet instead of creating a new one.

Save the wallet id and public_address. You’ll need these for the next steps.

2. Sign a Message

Now let’s sign a message with your newly created wallet:

curl -X POST "https://api.moonkey.fun/v1/wallets/wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK/sign_message" \
  -H "Authorization: Bearer sk_test_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "message": "Hello from MoonKey!"
  }'

const apiKey = process.env.MOONKEY_SECRET_KEY;
const walletId = 'wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK';

const response = await fetch(
  `https://api.moonkey.fun/v1/wallets/${walletId}/sign_message`,
  {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${apiKey}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      message: 'Hello from MoonKey!'
    })
  }
);

const result = await response.json();
console.log('Message signed:', result.signature);

import requests
import os

api_key = os.environ.get('MOONKEY_SECRET_KEY')
wallet_id = 'wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK'

url = f"https://api.moonkey.fun/v1/wallets/{wallet_id}/sign_message"
headers = {
    "Authorization": f"Bearer {api_key}",
    "Content-Type": "application/json"
}
payload = {
    "message": "Hello from MoonKey!"
}

response = requests.post(url, json=payload, headers=headers)
result = response.json()
print(f"Message signed: {result['signature']}")

The response will contain the signed message:

{
  "wallet_id": "wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK",
  "wallet": {
    "id": "wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK",
    "app_id": "app_25ldv51seNohTaYRsxdfoxMlAa2",
    "user_id": "user_26l6ha8syVN8oqmaHaFShTxZ5RC",
    "public_address": "0xb6acedc0cdcab7a4bb6c236976bb7df63bbcd567",
    "wallet_type": "ethereum",
    "verified": true,
    "is_default": true,
    "is_read_only": false,
    "is_imported": false,
    "created_at": 1647985945,
    "updated_at": 1647985945
  },
  "signature": "0xc8723cfad978035ad3b960beade5237477aa91a9b01ba238d859e2a6e0fbded322e4732d3252afc4f7bec0018cc7bdddfe90547cc4fa985a400744315316198e01"
}

3. Send a Transaction

Finally, let’s send a transaction on Ethereum’s testnet, Sepolia:

curl -X POST "https://api.moonkey.fun/v1/wallets/wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK/sign_transaction" \
  -H "Authorization: Bearer sk_test_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "eth_transaction": {
      "to": "0xE9534C9fAF3cDBc636c25E1981A80EfaE03f187a",
      "value": "0x38d7ea4c68000",
      "nonce": "0x8",
      "maxPriorityFeePerGas": "0x77359400",
      "maxFeePerGas": "0xdf8475800",
      "gas": "0x5208",
      "chainId": "0xaa36a7"
    }
  }'

const apiKey = process.env.MOONKEY_SECRET_KEY;
const walletId = 'wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK';

const response = await fetch(
  `https://api.moonkey.fun/v1/wallets/${walletId}/sign_transaction`,
  {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${apiKey}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      eth_transaction: {
        to: '0xE9534C9fAF3cDBc636c25E1981A80EfaE03f187a',
        value: '0x38d7ea4c68000', // 0.001 ETH in wei (hex)
        nonce: '0x8',
        maxPriorityFeePerGas: '0x77359400',
        maxFeePerGas: '0xdf8475800',
        gas: '0x5208',
        chainId: '0xaa36a7' // Sepolia testnet
      }
    })
  }
);

const result = await response.json();
console.log('Transaction signed:', result.signed_transaction);

import requests
import os

api_key = os.environ.get('MOONKEY_SECRET_KEY')
wallet_id = 'wallet_2Cu2uYcbwY9kcAFe2zd0P0SHftK'

url = f"https://api.moonkey.fun/v1/wallets/{wallet_id}/sign_transaction"
headers = {
    "Authorization": f"Bearer {api_key}",
    "Content-Type": "application/json"
}
payload = {
    "eth_transaction": {
        "to": "0xE9534C9fAF3cDBc636c25E1981A80EfaE03f187a",
        "value": "0x38d7ea4c68000",  # 0.001 ETH in wei (hex)
        "nonce": "0x8",
        "maxPriorityFeePerGas": "0x77359400",
        "maxFeePerGas": "0xdf8475800",
        "gas": "0x5208",
        "chainId": "0xaa36a7"  # Sepolia testnet
    }
}

response = requests.post(url, json=payload, headers=headers)
result = response.json()
print(f"Transaction signed: {result['signed_transaction']}")

You’ll need to fund your wallet with Sepolia ETH for this step. Use a Sepolia faucet to send test ETH to your wallet’s public_address.

The response will contain the signature and signed transaction:

{
  "wallet_id": "wallet_26l6hdwAXQr0y573AhQTXNDkyqK",
  "wallet": {
    "id": "wallet_26l6hdwAXQr0y573AhQTXNDkyqK",
    "app_id": "app_25ldv51seNohTaYRsxdfoxMlAa2",
    "user_id": "user_26l6ha8syVN8oqmaHaFShTxZ5RC",
    "public_address": "0xb6acedc0cdcab7a4bb6c236976bb7df63bbcd567",
    "wallet_type": "ethereum",
    "verified": true,
    "is_default": true,
    "is_read_only": false,
    "is_imported": false,
    "created_at": 1647985945,
    "updated_at": 1647985945
  },
  "signature": "0x744b61c44cdb250b89438709a9438a0b9e30c9c46e29776c93fb5e150e56021a",
  "signed_transaction": "0xb87502f87205088477359400850df847580082520894e9534c9faf3cdbc636c25e1981a80efae03f187a87038d7ea4c6800080c001a0cd31b38c3e3a48230bee2d5c687a0b2a5efcb298c58cfc3b43449eefd17857cfa03f95b8bcad72f7bdca59025e797781f4ba3fde826f62b9d6997aaf19a7d7591b"
}

Broadcasting the Transaction

The signed_transaction is ready to be broadcast to the Ethereum network. You can use it with the eth_sendRawTransaction RPC method:

const signedTx = result.signed_transaction;

// Using a public RPC endpoint
const rpcResponse = await fetch('https://rpc.sepolia.org', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'eth_sendRawTransaction',
    params: [signedTx],
    id: 1
  })
});

const txResult = await rpcResponse.json();
console.log('Transaction hash:', txResult.result);

import requests

signed_tx = result['signed_transaction']

# Using a public RPC endpoint
rpc_url = "https://rpc.sepolia.org"
rpc_payload = {
    "jsonrpc": "2.0",
    "method": "eth_sendRawTransaction",
    "params": [signed_tx],
    "id": 1
}

rpc_response = requests.post(rpc_url, json=rpc_payload)
tx_result = rpc_response.json()
print(f"Transaction hash: {tx_result['result']}")

View your transaction on Sepolia Etherscan by searching for the transaction hash.

Understanding Transaction Parameters

When sending a transaction, you need to provide several parameters:

Parameter	Description	Example
`to`	Recipient address	`0xE9534C9fAF3cDBc636c25E1981A80EfaE03f187a`
`value`	Amount in wei (hex)	`0x38d7ea4c68000` (0.001 ETH)
`nonce`	Transaction count for the address	`0x8`
`maxPriorityFeePerGas`	Priority fee (hex)	`0x77359400`
`maxFeePerGas`	Max total fee (hex)	`0xdf8475800`
`gas`	Gas limit (hex)	`0x5208` (21000 for simple transfer)
`chainId`	Network chain ID (hex)	`0xaa36a7` (Sepolia)

Use tools like eth-converter.com to convert between decimal and hex values for ETH amounts and gas prices.

Creating Solana Wallets

MoonKey also supports Solana wallets. To create a Solana wallet, simply change the wallet_type:

curl -X POST "https://api.moonkey.fun/v1/wallets/create" \
  -H "Authorization: Bearer sk_test_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "wallet_type": "solana",
    "user_id": "user_2Cu2uVhYy0OVgRcO913OsqIVaPI"
  }'

const response = await fetch('https://api.moonkey.fun/v1/wallets/create', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${apiKey}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    wallet_type: 'solana',
    user_id: userId
  })
});

const wallet = await response.json();
console.log('Solana wallet created:', wallet.public_address);

Best Practices

Security

Never expose API keys - Keep your secret API keys secure on your backend
Use test keys for development - Test thoroughly before switching to live keys
Validate user actions - Always verify that requests come from authenticated users

Transaction Safety

Verify addresses - Always double-check recipient addresses before sending transactions
Test on testnet first - Use Sepolia for Ethereum or Devnet for Solana before going to mainnet
Monitor transaction status - Track transactions and handle failures gracefully
Use appropriate gas limits - Ensure transactions have enough gas to complete

Error Handling

Always implement proper error handling for API requests:

try {
  const response = await fetch('https://api.moonkey.fun/v1/wallets/create', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${apiKey}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      wallet_type: 'ethereum',
      user_id: userId
    })
  });

  if (!response.ok) {
    const error = await response.json();
    throw new Error(error.message || 'Failed to create wallet');
  }

  const wallet = await response.json();
  return wallet;
} catch (error) {
  console.error('Wallet creation failed:', error.message);
  // Handle error appropriately for your application
}

Troubleshooting

Common Issues

401 Unauthorized

Verify your API key is correct
Ensure you’re using the Bearer token format
Check that your API key hasn’t been revoked

404 Not Found

Verify the wallet ID is correct
Ensure the wallet belongs to your app
Check that the user ID exists

Transaction Fails

Verify the wallet has sufficient balance
Check that gas limits and fees are appropriate
Ensure the recipient address is valid
Verify you’re on the correct network (testnet vs mainnet)

Rate Limiting

Implement exponential backoff for retries
Cache wallet data when possible
Batch operations where appropriate

Support

Need help?

Check the API Reference for detailed endpoint documentation
Review authentication setup for configuration help
Contact support for technical assistance

Main

Frontend SDKs

REST API

Concepts and Resources

Prerequisites

Create a User (Optional)

1. Create a Wallet

2. Sign a Message

3. Send a Transaction

Broadcasting the Transaction

Understanding Transaction Parameters

Creating Solana Wallets

Best Practices

Security

Transaction Safety

Error Handling

Troubleshooting

Common Issues

Support

​Prerequisites

​Create a User (Optional)

​1. Create a Wallet

​2. Sign a Message

​3. Send a Transaction

​Broadcasting the Transaction

​Understanding Transaction Parameters

​Creating Solana Wallets

​Best Practices

​Security

​Transaction Safety

​Error Handling

​Troubleshooting

​Common Issues

​Support

Prerequisites

Create a User (Optional)

1. Create a Wallet

2. Sign a Message

3. Send a Transaction

Broadcasting the Transaction

Understanding Transaction Parameters

Creating Solana Wallets

Best Practices

Security

Transaction Safety

Error Handling

Troubleshooting

Common Issues

Support