# Calling Functions
## *"Call Function"* Action
Actions are meant to make the UI more functional. Using actions, you can navigate to a different page, change state of a widget, launch URLs, etc. In this case, we need to call a custom function in the SDK. So, we use the *Call Function* action.
Head over to *Develop Tab* located in the app bar.
Develop Tab
You should see the *Actions Panel* in the right. Now, select the node you wish to add the action to.
Node selected
To add an action, tap on the *add icon* and select *"Call Function Action"* from the dropdown.
Adding Call Function Action
Next, tap on the *settings icon* to open the settings window.
Action Settings Window
Enter the custom function's name in the *Function Name Field*.
Function Name Field
Action to call a custom function is now added to the node. Now, we need to provide the function in the SDK.
## Functions Field
We can provide custom functions to the `CodelesslyWidget` using its `functions` parameter which is of type `Map>`. Map's key is the name of the function and value is `CodelesslyFunction` class that takes in the function itself in its constructor.
`CodelesslyFunction` has a parameter `call` which is a function with generic return type `T`. Here's an example of how we can declare functions in the widget.
```dart
CodelesslyWidget(
functions: {
'expandForecastPage': CodelesslyFunction((context, ref, params) {...}),
}
);
```
`ref` is an instance of `CodelesslyContext` that you may use to access data and other functions from the SDK.
`params` is a Map that contains any parameters passed by the function when it is called. These parameters can be defined on the function call from the Editor.
Now, node can access the function and call it on relevant trigger (*click* in this case).
