OnlyCat
OnlyCat Smart Cat Flap
- HACS component
- Cloud required
- Wi-Fi
Prices verified November 2026
Our verdict
The only flap here with prey detection: it checks whether the cat is carrying prey and holds the door shut for that attempt, letting the cat back in without it. It needs mains power (3 m cable included), is designed for cats up to about 6 kg (the maker says cats around 8 kg usually cope, not guaranteed), and the camera points at your doorstep. OnlyCat's own page shows GBP pricing from £275 to £499 and offers a one-time purchase or a rolling subscription version; the subscription version will not run without an active connection, so choose the one-time version if offline resilience matters.
What can Home Assistant control on the OnlyCat Smart Cat Flap?
| Control | Type | What it does |
|---|---|---|
| Pet location | Device tracker | Home/away per pet with last-seen time. |
| Contraband detection | Binary sensor | Fires when the flap detects prey, for notifications. |
| Lock state | Binary sensor | Whether the flap is locked. |
| Remote unlock | Button | Unlock the flap remotely; a reboot button is also provided. |
| Door policy | Action | update_device_policy changes the active door policy from automations. |
Community integration from the OnlyCatAI/onlycat-home-assistant repository, added as a custom HACS repository, then configured with an API key you create in the OnlyCat app (enable Developer Mode, then Account > API Keys). It provides a device tracker for each pet (home/away plus last seen), binary sensors for flap connection, lock state, contraband (prey) detection, human detection, flap events with RFID code and trigger source, device errors and the last activity video and image, plus reboot and remote-unlock buttons. Two actions: set_pet_location to correct presence, and update_device_policy to change the active door policy. You cannot create or edit pet profiles from Home Assistant. Presence can drift if a cat uses another exit, so expect to use set_pet_location.
Specs
| power | Mains, 3 m cable and adaptor included (OnlyCat) |
|---|---|
| cat weight | Designed for cats up to 6 kg; around 8 kg usually fine, not guaranteed (OnlyCat) |
| price range | £275.00 to £499.00 on onlycat.com; the page does not say which price belongs to which version |
| connectivity | Wi-Fi needed for setup and app features; the one-time version keeps working without internet after setup, the subscription version needs to check its subscription (OnlyCat) |
How does the OnlyCat Smart Cat Flap compare?
| Product | From | Protocol | Local control | Integration |
|---|---|---|---|---|
| OnlyCat Smart Cat Flap (this product) | — | Wi-Fi | Cloud | HACS |
| Litter-Robot 4 | £699 | Wi-Fi | Cloud | Native |
| SureFeed Microchip Pet Feeder Connect | £155 | Wi-Fi | Cloud | Native |
| SureFlap Microchip Cat Flap Connect | £140 | Wi-Fi | Cloud | Native |
Frequently asked questions
- Does the OnlyCat Smart Cat Flap work with Home Assistant locally?
- Partly. The OnlyCat Smart Cat Flap connects to Home Assistant through a community integration installed through HACS, which relies on the OnlyCat cloud. It works in Home Assistant, but commands go via the internet and stop working during an outage of your connection or the OnlyCat service.
- Which protocol does the OnlyCat Smart Cat Flap use, and do I need a hub?
- The OnlyCat Smart Cat Flap uses Wi-Fi. To pair it with Home Assistant you need no hub — it joins your Wi-Fi network directly. OnlyCat's own hub is not required when you integrate through a community integration installed through HACS.
OnlyCat
OnlyCat Smart Cat Flap
Check price at OnlyCat