Code discovered in the recently released iOS 27 reveals Apple is secretly preparing to allow Siri to work seamlessly with rival artificial intelligence models. Freshly discovered references in the software highlight deep integration with both ChatGPT and Claude. Crucially, the code indicates users might soon replace Siri’s underlying system entirely with a preferred outside engine.
This significant discovery comes from an established developer known as “pdfu” on X. This leaker maintains a highly accurate track record regarding iOS discoveries. They recently identified two private frameworks hidden inside candidate builds for iOS 27 and macOS Golden Gate.
iOS 27 and macOS Golden Gate have private hooks that let apps add Siri Extensions and replace Siri AI’s server backend with third-party models.
First, here’s Claude running as a Siri Extension using the Model Delegation API in App Intents. Claude can appear in Siri’s “Ask…”… pic.twitter.com/OXKHQ4hDY8
— pdfu (@itspdfu) September 13, 2026
The primary mechanism is labeled “Model Delegation.” This framework allows outside AI agents to function as dynamic extensions within Apple’s ecosystem. It natively builds on Apple’s sophisticated App Intents system. Consequently, Anthropic’s Claude could operate similarly to the currently active ChatGPT extension.
In a compelling video demonstration, pdfu showcased this delegation working seamlessly. Using a Mac, they selected Claude from an “Ask” dropdown menu. When asked to schedule a reminder, Claude processed the intricate request and then handed the actionable data back to Siri.
This strict handoff boundary illustrates Apple’s strategic design philosophy perfectly. Claude parses complex natural language instructions utilizing its superior reasoning capabilities. However, Siri ultimately executes the final system actions natively. Therefore, Apple ensures sensitive user data and core settings remain strictly protected.
A second, more profound framework called “Model Manager Services” points to larger shifts. Utilizing an Inference Provider protocol, this could allow developers to entirely replace Siri’s server model. In one demonstration, the GPT 5.6 Terra model successfully utilized Apple’s native Siri planner prompt.
Several major caveats still surround this leak. Apple has not publicly opened this delegation entitlement to outside developers. Currently, only the native ChatGPT integration operates officially. Furthermore, no formal partnership between Apple and Anthropic has been announced.
Mounting regulatory pressure likely explains Apple’s sudden architectural shift. The European Union’s stringent Digital Markets Act essentially mandates opening foundational software features to competitors. The stakes are undeniably massive as both OpenAI and Anthropic prepare for highly lucrative public listings soon.
This feature is still not live for all the users, despite the rollout of iOS 27 last night.
