Platform notes

iOS

• Requires the voip background mode and a VoIP push certificate.
• Uses CallKit + PushKit + WebRTC's RTCAudioSession for manual audio control.
• Minimum iOS version: 15.1.

Android

• Requires MANAGE_OWN_CALLS permission.
• Minimum SDK: 26 (Android 8.0).
• Uses androidx.core:core-telecom.
• Incoming calls come via FCM data messages — the config plugin registers ExpoCallKitTelecomMessagingService automatically.

VoIP push token types

The VoIP push token type is reported as "APNS_VOIP" on iOS and "FCM" on Android — send both to your backend so it knows which transport to use.

Keeping connections alive in the background

This module hands the OS a CallKit/Core-Telecom call, which keeps the process alive during a call — but JS timers (setInterval, setTimeout) and JS-side network heartbeats are still subject to background throttling once the screen locks. If your media stack needs an app-level heartbeat (e.g. a WebSocket signalling channel) to survive the background, pair this module with react-native-nitro-keepalive-timer to get native timers that fire reliably while a call is active.