Privacy Policy & Audio Disclosures
Last updated: November 2026 • Effective for all versions of Tandem Mirror for macOS
1. The Core Philosophy: Zero-Knowledge & Local Air-Gap
Tandem Mirror was built on an uncompromising privacy foundation: your Mac and your Android device communicate exclusively with each other. Unlike legacy remote desktop or cloud-mirroring services, Tandem Mirror operates with zero cloud relay servers.
We do not operate streaming servers, we do not inspect your network traffic, and we do not store your data. All audio, video, clipboard contents, notification payloads, and file transfers remain strictly confined to your physical USB cable or your local private Wi-Fi network.
2. Audio & Call Sound Transmission (Where Does Your Sound Go?)
Tandem Mirror features real-time digital audio playback, enabling you to hear cellular phone calls and media directly through your MacBook speakers or connected headphones. Users frequently ask how this sound is handled:
- Direct Local Route: When an audio session starts (e.g., an active cellular call), raw digital PCM audio is streamed directly from your phone over your local connection (USB or local Wi-Fi) directly into your Mac's volatile random-access memory (RAM).
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In-Memory Playback via Apple CoreAudio: The audio packets are fed immediately into macOS native
AVAudioEnginebuffers for real-time hardware output. - Zero Disk Persistence (No Recording): Tandem Mirror is strictly an audio routing accessory, NOT a recording device or wiretap. Audio frames are never saved to disk, never encoded into audio files (.wav, .mp3), never transcribed into text, and never uploaded anywhere. Once played through your speaker, the memory buffer is immediately discarded.
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Isolated Loopback Sockets: The local audio tunnel binds exclusively to the local loopback interface (
127.0.0.1). No external devices on your network can connect to or eavesdrop on your audio session.
3. Clipboard Synchronization & File Transfers
Universal Clipboard transfers copied text and images between your Mac and phone via sub-millisecond local sockets. Clipboard data is processed in-memory solely to synchronize your pasteboards and is never logged or retained. When dragging files between Finder and your phone, data travels directly between local storage volumes without intermediate cloud hops.
4. Telemetry & Crash Reporting
To maintain high reliability across macOS updates, Tandem Mirror includes minimal, privacy-first diagnostic telemetry via Sentry. Sentry receives only anonymous crash traces (e.g., line numbers and stack traces during an unexpected exception). Sentry never receives your phone number, contact names, call audio, clipboard contents, or personal files.
5. Payment Processing via Merchant of Record
License purchases are processed by Lemon Squeezy, acting as our authorized global Merchant of Record (MoR). Lemon Squeezy handles order fulfillment, sales tax, currency conversion, and fraud prevention in accordance with PCI-DSS standards. Tandem Mirror never sees, handles, or stores your credit card numbers or payment credentials.
6. Contact & Data Inquiries
Because we do not collect personal data, we have no personal user databases to search, modify, or delete. If you have questions regarding our security architecture or privacy policies, contact us directly at tandemmac@proton.me.