Native iOS & Android
Dedicated native SDK on both platforms — not a WebView wrapper.
Voice & Video
Encrypted calls built into every Hat channel
Native voice and video on iPhone and Android — with CallKit on iOS, reliable long calls, and the same end-to-end encryption as your messages.
Native iOS & AndroidCallKit on iPhoneLong-call reliabilityChannel-scoped
Native on mobile
Real phone calls, not a browser hack
City of Hats uses native calling on iOS and Android so audio routes through your earpiece, Bluetooth, and lock screen like a normal call.
Native iOS & AndroidCallKit on iPhoneLong-call reliabilityChannel-scoped
Native on mobile
Real phone calls, not a browser hack
City of Hats uses native calling on iOS and Android so audio routes through your earpiece, Bluetooth, and lock screen like a normal call.
CallKit on iPhone
Incoming calls appear on your lock screen and integrate with the iOS phone UI.
Long-call reliability
Sessions designed for extended conversations — up to two hours with automatic token refresh.
Channel-scoped
Voice and video stay inside your existing encrypted Hat channels.
Web calling
Browser users can join from hats.cityofhats.com when native apps are not available.
Anonymous identity
Call using Hat identities — no carrier number exchange.
Premium limits
Free tier includes calling; Premium extends concurrent channels and durations.
🛡 Threat Model
Real phone calls, not a browser hack
No system is invulnerable. Stating what we defend against — and where our boundaries are — is more credible than claiming absolute security.
Real phone calls, not a browser hack
- Dedicated native SDK on both platforms — not a WebView wrapper.
- Incoming calls appear on your lock screen and integrate with the iOS phone UI.
- Sessions designed for extended conversations — up to two hours with automatic token refresh.
- Voice and video stay inside your existing encrypted Hat channels.
🛡 Threat Model
- No system is invulnerable. Stating what we defend against — and where our boundaries are — is more credible than claiming absolute security.
- City of Hats uses native calling on iOS and Android so audio routes through your earpiece, Bluetooth, and lock screen like a normal call.
No system is invulnerable. Stating what we defend against — and where our boundaries are — is more credible than claiming absolute security. Learn More →
Platform
Learn More
Start an encrypted call today
Download City of Hats on iOS or Android, open any Hat channel, and tap the call button.