Developer pdfu discovered in the iOS 27 and macOS Golden Gate private frameworks that Apple designed its new Siri AI architecture to support deep integration with third-party models. The system introduces a mechanism called Model Delegation, which allows external AI to function as Siri extensions.
In demonstrations, Anthropic’s Claude and OpenAI’s GPT-5.6 were shown interacting with the Siri framework. Claude can handle natural language requests, such as creating reminders in the Apple Reminders app, by delegating system-level tasks back to Siri. It can also perform tasks Siri cannot handle directly, like generating CSV files.
A second protocol, the Inference Provider, allows for even deeper integration. In this mode, models like GPT-5.6 can replace the local Siri planner and tool definitions. This enables the third-party AI to access personal data, request system operations, and generate responses presented through the native Siri interface and voice.
Experts suggest that the European Union’s Digital Markets Act likely influenced these architectural changes. The regulation mandates that Apple provide third-party developers with access to iOS hardware and software features equivalent to those used by its own services, a requirement the European Commission has explicitly applied to Siri AI.
Currently, these features are not available to the public. The Ask interface is limited to ChatGPT extensions in the macOS 27 Golden Gate release candidate, and Apple has not yet opened Model Delegation to third-party developers. Despite this, the underlying code indicates significant engineering preparation for future model interoperability.
