# Register Traits

The Google Assistant needs to be able to associate a query with a
command to send to your device. For this to work, you need to declare what kinds
of abilities your device supports. These abilities are known as *traits*. You
declare these traits within your device model.

Google has already created a wide variety of common [traits](https://developers.google.com/assistant/sdk/reference/traits)
found on many devices. These traits are not tied to just one device type, you can
use them as you choose.

## Add a trait

You previously defined a model, now update it by adding a trait. In this case,
add an On/Off trait to control an LED attached to your device.

1. Open the project in the [Actions Console](https://console.actions.google.com/).

2. Select the **Device registration** tab from the left navbar.

3. Click a model from the list to edit it.

   ![Model list](https://developers.google.com/static/assistant/sdk/images/console/model-list.png)
4. Click the pencil in the **Supported traits** box to add the trait.

   ![Edit traits](https://developers.google.com/static/assistant/sdk/images/console/supported-traits.png)
5. Select the **OnOff** checkbox. Click **SAVE**.

   ![Onoff trait](https://developers.google.com/static/assistant/sdk/images/console/trait-onoff.png)
6. Make sure to save changes to the model. Click **SAVE** again.

   ![Saved trait](https://developers.google.com/static/assistant/sdk/images/console/saved-trait.png)

## Next step

[Handle Commands](https://developers.google.com/assistant/sdk/guides/service/python/extend/handle-device-commands)