clientCredentials.php

<?php
require 'vendor/autoload.php';

use GuzzleHttp\Client;

const HOOTSUITE_CLIENT_ID = 'yourclientid'; // your client ID and secret are available through the developer dash
const HOOTSUITE_CLIENT_SECRET = 'yourclientsecret'; // if you don't have API access yet, email app.directory@hootsuite.com

$member_id = '17107276'; // the memberId of a user of your Hootsuite app, available through the dashboard SDK

$client = new Client([
    'base_uri' => 'https://platform.hootsuite.com'
]);

try {
	$response = $client->post('/auth/oauth/v2/token', [
	    'form_params' => [
	        'grant_type' => 'member_app',
	        'member_id' => $member_id 
	    ],
	    'headers' => [
	        'Authorization' => 'Basic ' . base64_encode(HOOTSUITE_CLIENT_ID . ':' . HOOTSUITE_CLIENT_SECRET)
	    ]
	]
	);
} catch (GuzzleHttp\Exception\ClientException $e) {
	// ...
}
$token = json_decode($response->getBody())->access_token;
try {
	$response = $client->get('/v1/me', [
	    'headers' => [
	        'Authorization' => 'Bearer ' . $token
	    ]
	]
	);
} catch (GuzzleHttp\Exception\ClientException $e) {
   // ...
}
$userDetails = (string) $response->getBody();