Authentication

Pass credentials from your application's secret provider at runtime. For bearer authentication, use the request token option or configure the handler with withToken().

$response = fetch($url, ['token' => $token]);

$handler = fetch_client()->getHandler()->withToken($token);
$response = $handler->get($url);

For API keys, use a header option. Use HTTPS and redact authorization data from logs. The offline behavior is covered by the authentication.php fixture in composer docs:examples.