You can include a `php.ini` file with your App Engine application. This
file lets you customize the behavior of the PHP interpreter directives.

See an example of the [default `php.ini` configuration](http://php72-ini.appspot.com/).

## Using a custom php.ini file

Place the `php.ini` file in your application's base directory where your
`app.yaml` file is located. It is loaded when the PHP interpreter is
initialized, before running your application code.

The file follows the same syntax as [other `.ini` files](https://en.wikipedia.org/wiki/INI_file).
A simple example might look like:

    ; This is a simple php.ini file on App Engine
    ; It enables output buffering for all requests by overriding the
    ; default setting of the PHP interpreter.
    output_buffering = "On"

A list of the core directives, along with their changeable mode values, is
[published on php.net](http://php.net/manual/en/ini.list.php).

You can override any PHP directive that has one of the following changeable mode
values:

- `PHP_INI_SYSTEM`
- `PHP_INI_ALL`
- `PHP_INI_PERDIR`

You can enable a set of [dynamically loadable extensions](https://docs.cloud.google.com/appengine/docs/standard/php-gen2/runtime#dynamically_loadable_extensions)
by using the `extension` directive.