PHP Code to Fetch current Coinbase Assets (Balances)

Below is a PHP implementation to fetch your current assets (balances) from the Coinbase API using authenticated requests:

PHP Code: Fetch Current Assets

<?php
// Coinbase API credentials
$apiKey = 'your_api_key';
$apiSecret = 'your_api_secret';

// API endpoint and request method
$method = 'GET';
$requestPath = '/v2/accounts';
$baseUrl = 'https://api.coinbase.com';

// Current timestamp
$timestamp = time();

// Message to sign
$message = $timestamp . $method . $requestPath;

// Generate HMAC SHA256 signature
$signature = hash_hmac('sha256', $message, $apiSecret);

// Prepare headers
$headers = [
    'CB-ACCESS-KEY: ' . $apiKey,
    'CB-ACCESS-SIGN: ' . $signature,
    'CB-ACCESS-TIMESTAMP: ' . $timestamp,
    'Content-Type: application/json',
];

// Initialize cURL
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $baseUrl . $requestPath);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

// Execute the API call
$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

// Handle response
if ($httpCode === 200) {
    $data = json_decode($response, true);
    echo "Your current assets:\n";
    foreach ($data['data'] as $account) {
        echo $account['currency'] . ": " . $account['balance']['amount'] . "\n";
    }
} else {
    echo "Failed to fetch assets. HTTP Code: $httpCode\nResponse: $response\n";
}
?>

Explanation of the Code

1. Authentication:
   • The CB-ACCESS-KEY, CB-ACCESS-SIGN, and CB-ACCESS-TIMESTAMP headers are required for Coinbase API authentication.
2. HMAC Signature:
   • The signature is generated by hashing the timestamp, HTTP method, and request path together using the API secret.
3. Request Path:
   • /v2/accounts fetches the balances of all assets in your account.
4. Error Handling:
   • If the HTTP response code is not 200, the script outputs an error message.
5. Output:
   • For each account, it prints the currency code and the balance.

Example Output

If the API call is successful:

Your current assets:
BTC: 0.01234567
ETH: 2.50000000
USD: 150.00

If there's an issue (e.g., invalid API key):

Failed to fetch assets. HTTP Code: 401
Response: {"errors":[{"id":"authentication_error","message":"Invalid API Key"}]}