As you may have noticed, Apple provides a very limited API to custom keyboard extensions. You have to implement much functionality from scratch, including the keyboard view itself.

KeyboardKit provides essential types and functionality to simplify building custom keyboards. It extends text document proxy to make it much more capable and lets you use SwiftUI instead of UIKit.

KeyboardKit also has a SystemKeyboard component that can be used to create keyboards that mimic the native iOS keyboard. It can be customized and styled to great extent.

KeyboardKit Pro unlocks pro features for the system keyboard. Information about Pro features can be found at the end of this article.

Keyboard input view controller

The KeyboardInputViewController is the most essential type in the library. Make your controller inherit this base class instead of UIInputViewController to get access to a bunch of additional capabilities.

Keyboard namespace

KeyboardKit has a Keyboard namespace with essential types, like AutocapitalizationType, Case, ReturnKeyType, and much more.

Keyboard context

KeyboardKit has an observable KeyboardContext class that provides information about the keyboard, a reference to the current textDocumentProxy, the current keyboardType, etc.

Keyboard behavior

KeyboardKit has a KeyboardBehavior protocol and standard implementation that can determine certain behaviors. It’s used by e.g. the StandardKeyboardActionHandler to make some decisions.

System keyboard

KeyboardKit has a SystemKeyboard that can be used to create keyboards that mimic the native iOS keyboard. It can be customized and styled to great extent.

KeyboardKit will by default use a standard SystemKeyboard. If you just want to use this standard view, you don’t have to do anything. You can however customize it or replace it altogether.

👑 Pro features

KeyboardKit Pro unlocks powerful preview and emoji capabilities for the system keyboard.

Emojis

KeyboardKit Pro makes SystemKeyboard use an EmojisKeyboard view as the standard emoji keyboard.

This means that by just registering a valid license key, your keyboard will automatically show an emoji keyboard when the keyboardType changes to .emojis. You can still use a custom one.

Preview

KeyboardKit Pro unlocks powerful tools to preview system keyboards and themes:

SystemKeyboardPreview(...)              // A live system keyboard preview.
SystemKeyboardPreviewHeader(...)        // A live system keyboard preview header.
SystemKeyboardThemePreview(...)         // A live theme preview.
SystemKeyboardThemePreviewHeader(...)   // A live theme preview header.

To preview many styles or themes at once, you can use these more lightweight previews:

SystemKeyboardButtonPreview(...)        // A system button preview.
SystemKeyboardButtonThemePreview(...)   // A system button preview for a theme.

These previews only render lightweight buttons.

Documentation

The information on this page is shortened to be easier to overview. For more information about this feature, code samples, etc., please see the online documentation.