iOS 27 lets Siri run Claude, ChatGPT and other third‑party AIs

Siri AI gets a hidden plug‑in system in iOS 27

Apple’s latest operating system arrives with a Siri that feels a lot smarter – it now runs on Google’s Gemini models, according to TechCrunch’s hands‑on review. But a deeper dive into iOS 27’s private frameworks, reported by MacRumors, shows Apple has also built a "Model Delegation" layer that lets third‑party large‑language models appear as Siri extensions.

How Model Delegation works

Code sleuth known as pdfu posted a video of the iOS 27 "Search or Ask" bar offering a menu item called Claude. Selecting it triggers a flow where Claude interprets the user’s request, then hands the result back to Siri for any system‑level action, such as creating a reminder. A second protocol, labelled Inference Providing, can replace Apple’s own server‑side Siri model entirely – the video shows a GPT‑5.6 model receiving Apple’s planner prompt and tool definitions, making tool calls, and feeding the answer back to Siri’s voice interface.

Which devices actually get the new Siri AI?

TechRadar notes that while iOS 27 rolls out to 33 iPhone models on September 14, the full Siri AI suite (including expressive voices and advanced dictation) is restricted to devices that run Apple’s "most powerful on‑device model" – essentially iPhone 15 Pro, iPhone 16 Pro, iPhone 17 Pro and later, plus recent M1‑class iPads and MacBooks. Those devices can also use the new Model Delegation extensions, but the Claude option is still hidden behind an entitlement that Apple has not opened to developers.

European Union restrictions

Apple’s own blog post, cited by TechRadar, explains that the Digital Markets Act prevents Apple from shipping Siri AI to iOS devices in the EU or China. The same AI is still available on macOS 27 and visionOS 27 for EU users, a workaround that highlights the regulatory pressure shaping Apple’s AI roadmap.

What this could mean for developers

If Apple eventually exposes the Model Delegation entitlement, developers could ship their own LLM‑backed assistants that run inside Siri’s familiar voice and UI. For now, the only publicly visible extensions are the built‑in Gemini‑based assistant and the experimental Claude and ChatGPT demos captured by pdfu. The discovery suggests Apple is preparing a more modular AI stack, possibly to satisfy regulators and to keep its ecosystem flexible as the LLM market evolves.

User experience today

For most iPhone owners, Siri feels more capable – it can draft messages, fetch on‑screen context and even answer visual questions through the Camera app, as noted by TechCrunch. Power users with a supported Pro‑class device can experiment with the hidden extensions, but they must enable them via the undocumented "Ask…" menu in the Siri app.

Bottom line

Apple has shipped a Siri that is both smarter out‑of‑the‑box and secretly extensible. The Model Delegation framework proves the company is serious about making Siri a universal front‑end for any LLM, but regulatory and entitlement hurdles mean the feature is still a glimpse of what may come in future releases.