Automatic API Event Trigger in PI

• Trying to automatically update a resource with information from Cisco PI using the API. What needed is to trigger an alarm or an event and send that information instantly to a python server app. Will it be able to use that information to trigger other behaviors from the app.
• For instance, if an interface goes down, SYSLOG would alert PI to a CRITICAL alarm. PI would then initiate a resource update the app. 
• Is there a way for PI to do this natively, or should it be considering creating an updater in the app to constantly monitor the state of a certain device and/or Live SYSLOG server.

The API doesn't support for your use case, unfortunately.  Prime Infrastructure does include the Notifications API,  it does not supports listening for new alarms, just  like device lifecycle events.  We did consider adding WebSocket support to our framework, which would allow us to update an API client in near real-time about updates to a particular API resource, but we haven't implemented against it yet. 

However, the trap receiver functionality in Prime Infrastructure should cover what you need.  You'll have to setup a trap receiver (there are various Python package, like PySNMP and trapperkeeper, for this purpose) and then configure Prime Infrastructure to send the relevant traps to it (you can configure the alarm levels and categories filters to match your interests).