in index.php, line 6

With booleans, only strict comparison (with === operator) should be used to lower bug risks and to improve performances.

<?php

include 'config.php';
include 'functions.php';
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    if (!isset($_GET['token']) || $_GET['token'] == null) {
        // Not authenticated
    $error['status'] = '401';
        $error['description'] = ' Unauthorized';
        header('Content-Type: application/json');
        echo json_encode($error);

We need a favicon!

in client.php, line 18

With booleans, only strict comparison (with === operator) should be used to lower bug risks and to improve performances.

    'Authorization: '.$token,
    'Content-Length: '.strlen($data_string), ]
);

$result = curl_exec($ch);
if ($result == null) {
    echo 'null';
}
echo $result;

We need a banner for the Activity project.
It will be located at the top of our github README and the creator will be credited in the Credits section.
It should be simple, contain the word Activity and the logo.
This is an awesome oportunity for newcomers to start working on a Github project!

in index.php, line 40

With booleans, only strict comparison (with === operator) should be used to lower bug risks and to improve performances.

        exit();
    }
    $token = $result->fetch_assoc();
// Insert activity
} elseif ($_SERVER['REQUEST_METHOD'] === 'GET') {
    if (!isset($_GET['token']) || $_GET['token'] == null) {
        // Not authenticated
    $error['status'] = '401';
        $error['description'] = ' Unauthorized';
        header('Content-Type: application/json');
        echo json_encode($error);

We currently have clients in:

• PHP
• Bash (cURL)
• NodeJS
• GO
• Python
• Ruby
• .NET

If you have a little free time, take a minute testing the clients in your server and report here.

If you know a programming language that isn't listed above, feel free to create a client.