ChannelPreferences

Per-channel opt-in flags.

Omitting a channel leaves its current setting untouched; setting it to false suppresses every notification on that channel for this subscriber, including ones your workflow marks as CRITICAL. Use a category override if you need an exemption for one kind of message.

emailboolean | nullnullable

Allow email delivery.

pushboolean | nullnullable

Allow mobile push delivery.

smsboolean | nullnullable

Allow SMS delivery.

voiceboolean | nullnullable

Allow voice calls.

whatsappboolean | nullnullable

Allow WhatsApp delivery.

ChannelPreferences

{
  "email": true,
  "push": true,
  "sms": true,
  "voice": true,
  "whatsapp": true
}