Search-based Alerts

To get alerts only when an event matches a specific query, just pin the query.

1. Perform a search like "people approaching walkway" so that the query is in the search history dropdown, then
2. Pin the query in your search history shown when you click inside the search box.

As an example, if I want to get alerts when a car approaches my driveway, I can do a search for “car approaching driveway”:

Once I've used that query to search, it's in my search history:

I then pin the query by pressing the thumbtack icon, which turns black:

 To turn alerts off without unpinning your queries, see How do I turn alerts on/off. 

See What type of Events can be detected automatically for Alerts?