iOS 27 code shows Siri can use ChatGPT or Claude models

A code researcher known as pdfu has shared findings from private frameworks in iOS 27 and macOS Golden Gate showing that Apple built its new Siri to work deeply with third-party AI models. According to MacRumors, a mechanism called Model Delegation lets Claude appear as a Siri extension, like the existing ChatGPT extension. In the shared video, Claude creates a CSV file, a task Siri cannot do itself.

A second protocol goes further. An inference provider in Model Manager Services can replace Apple's server-side Siri model entirely. In the demo, GPT-5.6 receives Siri's planner prompt and tool definitions, summarizes emails and sends a message through Messages. Apple has not opened this entitlement to third parties. The EU's Digital Markets Act requires Apple to give third parties effective access to features available to its own services.