Share Your Rest.
Own Your Data.
The intimate health-sharing app built on absolute privacy. Tether bridges your Apple Health sleep data directly to your partner and your local AI—end-to-end encrypted, natively synced.
Zero-Knowledge Cloud
Powered by Curve25519 end-to-end encryption. We route your encrypted sleep metrics, but we never see them. Only you and your authorized connections hold the keys.
Intimate Partner Sync
Stay connected without texting. Seamlessly sync your daily sleep summary and health awareness to your partner securely in the background.
Local AI Integration
Connect your own local AI via the Model Context Protocol (MCP). Speak to your health data using private LLMs running on your own desktop, completely offline.