QUESTION

 How do I add details about the triggering event to a Custom Webhook alert from Panther so that I can extract these details later?

ANSWER

You can pass a JSON object to any webhook destination by using the alert_context function in your detection code. The function must return a dictionary of values you want to pass along with the alert. Panther will convert this dictionary into a JSON object, which is attached to the body of the POST request sent as the alert.