Looking to expand what your Shelly devices can do?
The Shelly Plus Add-On is a small module that connects to select Shelly devices and allows you to add external sensors or switch inputs. It doesn’t work on its own—but when paired with a compatible relay like the Shelly 1 Gen 3, it opens up new automation possibilities.
So… what exactly does it do?
The Shelly Add-On gives your relay the ability to monitor or respond to external signals—like door contacts, PIR sensors, float switches, or toggle switches. Think of it like adding more “eyes” to your system.
You can use it to:
- Trigger automations from a door or motion sensor
- Monitor when a physical switch is activated
- Feed sensor data into Home Assistant or another controller
It’s input-only — the Add-On doesn’t control power, it listens for signals.
Compatible Devices
The Shelly Plus Add-On works with:
- Shelly Plus 1
- Shelly Plus 1PM
- Shelly 1 Gen 3
- Other compatible Shelly Plus relays
It connects via the expansion port on the side of the relay (no extra power supply needed).
This setup allows you to connect physical switches or sensors without needing an additional relay.
Real-World Uses
Here are just a few ways people use the Shelly Add-On:
- Garage door open/close monitoring with a reed switch
- Light automation using a motion or PIR sensor
- Water level detection with a float switch
- Physical override switch for smart lighting
It’s ideal for where space or wiring is limited.
Ready to expand your Shelly setup?
Check out the Shelly Plus Add-On and compatible relays in our store:
