Custos (the "App") is developed and maintained by Spock Hsueh. It turns two iPhones into a baby and pet monitor: one device watches the crib or play area, the other lets you check in. Because the App handles a live camera and microphone feed of your home, we designed it so that the video and audio never leave your control.
The short version. Video and audio are never uploaded to us — we operate no server that can view your camera. By default nothing is recorded at all. If you choose to turn on Event Clips, short clips are saved only on your own device and are never transmitted anywhere. On your home network the live feed travels directly between your two devices; when you are away it travels over an end-to-end encrypted connection, and the relay server that may forward it can only see encrypted bytes.
The App requires camera and microphone access on the monitoring device to function. This live feed is:
You may optionally enable Event Clips in Settings. When enabled, the App saves a short clip (roughly 30 seconds before and after an alert such as crying or a possible roll-over) so you can review what happened. Two formats are available:
In both cases the clips are:
Event Clips are disabled by default. If you never turn them on, nothing is ever recorded.
To detect crying, barking, movement, and sleeping position, the App analyzes the camera and microphone feed entirely on the device using Apple's built-in Vision and SoundAnalysis frameworks. No images, audio, or biometric data are sent anywhere for analysis. Only the conclusion (for example, "crying detected at 02:13") may be shared as described in section 1.4.
The App does not perform facial recognition or identify individuals. Face detection is used solely to determine whether a face is visible in frame, which powers the "may have rolled over" alert.
Remote alerts and away-from-home viewing are optional features. If you enable them, you sign in with Sign in with Apple, and we store via Firebase:
We do not request or store your email address or phone number. If you use these features, the App works fully without an account, limited to your home network.
If you enable remote alerts, the App records short event entries so notifications can be delivered to your family members:
These entries contain no images and no audio — they are the textual equivalent of "crying detected at 02:13."
To establish an away-from-home connection, the two devices briefly exchange technical connection descriptors (WebRTC session descriptions and network candidates, which include your devices' IP addresses). These records are deleted as soon as the connection is established and contain no media.
Performance logs used to evaluate overnight stability (temperature, frame rate, connection state) are written to the App's local storage on your own device and are never transmitted.
| Data Type | Storage / Path | Can We Access? |
|---|---|---|
| Live video & audio | In transit only — direct between your devices, or end-to-end encrypted relay | ❌ Never uploaded, never viewable by us |
| Detection analysis (crying, movement, position) | On device, in memory | ❌ No |
| Event Clips (optional, off by default) | Local device only — the recording device's own storage | ❌ No |
| Pairing code, safe-zone settings, preferences | Local device (Keychain / app storage) | ❌ No |
| Performance logs | Local device only | ❌ No |
| Account, family membership, push tokens | Google Firebase (only if you enable remote alerts) | ✅ Yes — technical records, no media |
| Alert metadata | Google Firebase (only if you enable remote alerts) | ✅ Yes — event type & time, no media |
| Encrypted relay traffic (away from home) | Cloudflare TURN — forwards encrypted bytes, retains no content | ❌ Encrypted; not readable by us or Cloudflare |
| Crash & anonymous usage reports | Google Firebase | ✅ Aggregate only |
We do not operate our own media server. No video or audio from your home ever passes through, is stored on, or is backed up to any system we control.
The App uses the following third-party services. Please refer to their privacy policies for details:
While Custos is used to watch over infants and young children, the App is not directed at children. Its users are caregivers — parents, grandparents, and other adults. The camera is operated by you as the legal guardian, and the resulting video is never transmitted to us. If you enable Event Clips, the clips remain solely on your own device.
The App does not:
Under COPPA (U.S. Children's Online Privacy Protection Act) and GDPR-K guidelines, Custos is classified as a "parenting tool" rather than a children's service.
If we make material changes to this policy, we will update this page and revise the "Last updated" date. For substantive privacy changes (such as adding a new third-party service), we will display an in-app notice.
For any privacy questions or to exercise your data rights, including account deletion, please contact: