# Extending The App Object

The [`App.extend()`](https://cement.readthedocs.io/en/3.0/api/core/foundation/#cement.core.foundation.App.extend) method provides a mechanism that allows plugins, extensions, or the app itself to add objects or functions to the global application object.

For example, a plugin might extend the `App` with an `api` member allowing developers to call `app.api.get(...)`. The application itself does not provide `app.api`. However, the plugin does. As plugins are often third party, it is not possible for the plugin developer to simply sub-class the `App` class and add the functionality because the class is already instantiated by the time plugins are loaded.

{% tabs %}
{% tab title="Example: Extending the App Object" %}

```python
from cement import App

def example_func():
    print('Inside example_func')

def extend_myapp(app):
    app.extend('example', example_func)

class MyApp(App):
    class Meta:
        label = 'myapp'
        hooks = [
            ('post_setup', extend_myapp),
        ]

with MyApp() as app:
    app.run()

    # call the extended object or function
    app.example()
```

Alternatively from within an extension or plugin:

```python
def example_func():
    print('Inside example_func')

def extend_myapp(app):
    app.extend('example', example_func)

def load(app):
    app.hook.register('post_setup', extend_myapp)
```

{% endtab %}

{% tab title="cli" %}

```
$ python test.py
Inside example_func
```

{% endtab %}
{% endtabs %}

{% hint style="info" %}
Extended members can be anything from instantiated objects to callables of any kind. Its use case is varied and arbitrary... but should be documented well by the developer that is extending it.
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.builtoncement.com/additional-topics/extending-applications.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.