API Geofence devices

As I can through the api, know if a device is within a geofence?
thanks

There is no such API at the moment. You can only listen for geofence enter/exit events.

Ok, how can I see that?

Through websocket api. Check official web app for more details.

can you said me ulr? thanks

Please next time use search instead of asking questions like this.

https://github.com/tananaev/traccar-web