Definition

CXCallController is the CallKit object responsible for sending app-initiated call action requests to the iOS telephony system.

It is used when your app wants to:

• start a call
• end a call
• mute a call
• hold a call

Core Concept

CXCallController does not directly perform call actions.

Instead, it:

1. creates a request
2. wraps it inside a CXTransaction
3. sends it to the system
4. waits for CallKit to approve and execute it

Direction of Communication

Your App
    ↓
CXCallController
    ↓
iOS Telephony System

This is the opposite direction of:

CXProvider