MODX Connector and External API: Testing without Production Credentials

Confirmed facts

The MODX 3.x connector reads the api_key directly from its configuration and sends HTTP requests regardless of whether the key is a production value or a placeholder. No built‑in toggle for sandbox vs. production exists.

Recommended approach

1. Add a custom system setting, e.g. connector_test_mode (type: Yes/No) via System Settings → New Setting or in core/config/config.inc.php.
2. Create a subclass of the connector class you are using (e.g. modX\connectors\request or the service‑specific request class). Override the method that builds the request – usually prepare() or send(). Inside the override, check $modx->getOption('connector_test_mode'). If true, either return a canned response or use a dummy api_key (or skip the HTTP call entirely).
3. Register the subclass so MODX uses it instead of the default class. The simplest way is to add a plugin on the OnManagerPageInit (or OnInit) event that replaces the service in the container:

   $modx->getService('request', 'myNamespace\connectors\request', $modx->getOption('core_path') . 'connectors/request.php');

   Replace the class name with your own.
4. Clear the cache and verify that the setting is readable (log the value) and that when connector_test_mode is enabled no outbound HTTP request is made.

Are you performing these tests through the MODX Manager (browser) or via automated PHPUnit tests? The answer determines whether a service‑plugin approach or a PHPUnit mock handler is more appropriate.