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As PHP version 5.5 is no longer supported by the community, we strongly recommend new apps use the PHP 7+ runtime.

Using the Modules API

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The Modules API provides functions that return information about the current operating environment (module, version, and instance).

The Modules API also has functions that retrieve the address of a module, a version, or an instance. This allows an application to send requests from one instance to another, in both the development and production environments.

Add the following use statement to the top of your file:

use google\appengine\api\modules\ModulesService;

The following code sample shows how to get the module name and instance id for a request:

$module = ModulesService::getCurrentModuleName();
$instance = ModulesService::getCurrentInstanceId();

The instance ID of an automatic scaled module will be returned as a unique base64 encoded value, e.g. e4b565394caa.

You can communicate between modules in the same app by fetching the hostname of the target module:

use google\appengine\api\modules\ModulesService;
$url = 'http://' . ModulesService::getHostname('my-backend') . '/';
$result = file_get_contents($url);

You can also use the URL Fetch service.