How much of the new Siri can a third-party app access beyond App Intents?

Hi all. I'm building a chat assistant app and want to bring in the new Siri. I can adopt App Intents, but I'm trying to understand how much of the new Siri's functionality, tools, and system access I actually get as a third-party developer. Is App Intents the full extent of what's available to third-party apps, or is more of the new Siri's capabilities and system access exposed to us? Thanks.

How much of the new Siri can a third-party app access beyond App Intents?
 
 
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