CallKit

Build VoIP calling experiences that integrate with the native iOS call UI using CallKit and PushKit. Covers incoming and outgoing call flows, PushKit VoIP registration, audio session coordination, and call directory extensions. Targets Swift 6.3 / iOS 26+.

Contents

• Capabilities and Key Types
• Core Calling Architecture
• Critical VoIP Push Rule
• Audio Session Lifecycle
• Route by Task
• Common Mistakes
• Review Checklist
• References

Capabilities and Key Types

Enable Voice over IP in Signing & Capabilities > Background Modes, and add the Push Notifications capability.