Using Asterisk AMI to call AGI

I’m developing an outbound telephony application. The Asterisk servers maintain a set of audio files they can play during some outbound calls.

I have a bank of three Asterisk servers that are managed separately from my application’s servers, and I do not have any kind of regular access to them to manually replace the audio files, but I can access Asterisk’s AGI directory.

I’ve developed a series of PHP AGI scripts that use cURL to download and replace audio files, however I need some kind of way of activating these AGI scripts from my application’s servers.

Is there any AMI command that can be used to initiate AGI scripts (with given parameters)? I know I can hack it by making an Action: Originate request with a Context that calls the AGI script (and the Originate just calls a dummy number), but I’m looking for something more ideal.