get_all_templates.php

<?php

namespace Examples\Templates;

require dirname(__FILE__).'/../bootstrap.php';

use SparkPost\SparkPost;
use GuzzleHttp\Client;
use Http\Adapter\Guzzle6\Client as GuzzleAdapter;

$httpClient = new GuzzleAdapter(new Client());

$sparky = new SparkPost($httpClient, ["key" => "YOUR_API_KEY"]);

$promise = $sparky->request('GET', 'templates');

try {
    $response = $promise->wait();
    echo $response->getStatusCode()."\n";
    print_r($response->getBody())."\n";
} catch (\Exception $e) {
    echo $e->getCode()."\n";
    echo $e->getMessage()."\n";
}