A working script that creates a CSV file using the data from a cURL request.

curlcsv.php

<?php
$url = 'http://sendgrid.com/';
$user = 'schoologysendgridapi';
$pass = '*********';

$params = array(
    'api_user'  => $user,
    'api_key'   => $pass,
    'email'     => 'ahandler@stewie.schoologize.com',
    'date'      => '1',
    'days'      => '30',
    'limit'     => '1000'
);

print_r($params);

$request =  $url.'api/blocks.get.json';

// Generate curl request
$session = curl_init($request);
       
// Tell curl to use HTTP POST
curl_setopt ($session, CURLOPT_POST, true);
// Tell curl that this is the body of the POST
curl_setopt ($session, CURLOPT_POSTFIELDS, $params);
// Tell curl not to return headers, but do return the response
curl_setopt($session, CURLOPT_HEADER, 0);
curl_setopt($session, CURLOPT_RETURNTRANSFER, true);
// obtain response
$response = curl_exec($session);
curl_close($session);

//Create CSV file
$decoded_file = json_decode($response, true);

$fp = fopen('file.csv', 'w');

foreach ($decoded_file as $fields) {
    fputcsv($fp, $fields);
}
fclose($fp);
?>