PHP Google Service account auth Calendar API

Question

I would like to share and add events to my own google calendar from my website. So, I don't want the oauth prompt. Because users who visite my website can also add event to my calendar.

I think I did the right thing but I have this error : Client is unauthorized to retrieve access tokens using this method, or client not authorized for any of the scopes requested

So, I don't sur if I need a paid workspace account to do that. If not, I can't understand where I failed ?

here is my code :

$client = new Google\Client();

$client->setAuthConfig('./secret.json');
$client->setApplicationName('app name');
$client->addScope(Google\Service\Calendar::CALENDAR_EVENTS);
$client->setSubject('[email protected]');
$client->setAccessType('offline');

$service = new Google\Service\Calendar($client);

$event = new Google\Service\Calendar\Event(array(
    'summary' => 'summary',
    'location' => 'street bla bla',
    'description' => 'first event',
    'start' => array(
        'dateTime' => '2021-11-30T10:00:00.000-05:00',
        'timeZone' => 'Europe/Brussels',
    ),
    'end' => array(
        'dateTime' => '2021-11-30T10:00:00.000-05:00',
        'timeZone' => 'Europe/Brussels',
    )
));

$service->events->insert('calendar_id', $event);

Thanks

Answer 1

The issue is that you are trying to set the subject or delegate to a normally Gmail email address $client->setSubject('[email protected]');

Service accounts only work with Google workspace domain accounts and only after you have properly set up delegation to a user on the domain.

Im sorry to tell you that you will not be able to use a service account with your gmail email address.

What you could do is run the code from the Sample project which uses an installed application and stores the refresh token. This code will be single user. You will have to monitor it a little as refresh tokens can expire although its not that common once your project is set into prodctuion.

require __DIR__ . '/vendor/autoload.php';

if (php_sapi_name() != 'cli') {
    throw new Exception('This application must be run on the command line.');
}

/**
 * Returns an authorized API client.
 * @return Google_Client the authorized client object
 */
function getClient()
{
    $client = new Google_Client();
    $client->setApplicationName('Google Calendar API PHP Quickstart');
    $client->setScopes(Google_Service_Calendar::CALENDAR_READONLY);
    $client->setAuthConfig('credentials.json');
    $client->setAccessType('offline');
    $client->setPrompt('select_account consent');

    // Load previously authorized token from a file, if it exists.
    // The file token.json stores the user's access and refresh tokens, and is
    // created automatically when the authorization flow completes for the first
    // time.
    $tokenPath = 'token.json';
    if (file_exists($tokenPath)) {
        $accessToken = json_decode(file_get_contents($tokenPath), true);
        $client->setAccessToken($accessToken);
    }

    // If there is no previous token or it's expired.
    if ($client->isAccessTokenExpired()) {
        // Refresh the token if possible, else fetch a new one.
        if ($client->getRefreshToken()) {
            $client->fetchAccessTokenWithRefreshToken($client->getRefreshToken());
        } else {
            // Request authorization from the user.
            $authUrl = $client->createAuthUrl();
            printf("Open the following link in your browser:\n%s\n", $authUrl);
            print 'Enter verification code: ';
            $authCode = trim(fgets(STDIN));

            // Exchange authorization code for an access token.
            $accessToken = $client->fetchAccessTokenWithAuthCode($authCode);
            $client->setAccessToken($accessToken);

            // Check to see if there was an error.
            if (array_key_exists('error', $accessToken)) {
                throw new Exception(join(', ', $accessToken));
            }
        }
        // Save the token to a file.
        if (!file_exists(dirname($tokenPath))) {
            mkdir(dirname($tokenPath), 0700, true);
        }
        file_put_contents($tokenPath, json_encode($client->getAccessToken()));
    }
    return $client;
}


// Get the API client and construct the service object.
$client = getClient();
$service = new Google_Service_Calendar($client);

// Print the next 10 events on the user's calendar.
$calendarId = 'primary';
$optParams = array(
  'maxResults' => 10,
  'orderBy' => 'startTime',
  'singleEvents' => true,
  'timeMin' => date('c'),
);
$results = $service->events->listEvents($calendarId, $optParams);
$events = $results->getItems();

if (empty($events)) {
    print "No upcoming events found.\n";
} else {
    print "Upcoming events:\n";
    foreach ($events as $event) {
        $start = $event->start->dateTime;
        if (empty($start)) {
            $start = $event->start->date;
        }
        printf("%s (%s)\n", $event->getSummary(), $start);
    }
}