Code in iOS 27 lets Claude and ChatGPT stand in for Siri
Found in iOS 27's shipping code, not officially announced: an App Intents path to wire any model into Siri, and a deeper hook to swap its backend.
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The 'Ask…' hook: your model answers, Siri acts
A developer got Claude running as a Siri extension through iOS 27's Model Delegation API in App Intents: pick it from Siri's 'Ask…' menu, it parses your request in natural language, then hands execution back to Siri to actually fire the intent — create a reminder, send a message. The model reasons; the OS acts.
The bigger door: replace Siri's brain outright
A second, deeper protocol buried in Model Manager Services — 'Inference Providing' — would let an external model such as GPT-5.6 Terra receive Apple's own Siri planner prompt and tool definitions and drive system actions directly, with no Siri middleman. It's in the binary but undocumented and off by default.
What actually ships today: App Intents 2.0
iOS 27 shipped Sept 14 with App Intents 2.0 — the real, documented surface to build against now: multi-turn conversations, streaming responses, a View Annotations API, and Apple's LanguageModel protocol for model-agnostic inference. Wire up voice-invocable intents this weekend so you're first in line when delegation opens.
The catch: the entitlement isn't yours yet
The gate is com.apple.developer.model-delegation — present in the code, absent from the developer portal, with no docs. On iOS it's not user-facing at all; only 'Ask ChatGPT' is live, and only on macOS 27. Estimates put broad third-party access at a 27.x point release or WWDC27.
Elsewhere: Copilot lets you dial cost vs. quality
GitHub shipped a control (Sept 14) to bias Copilot's auto model selection toward cheaper or higher-quality models — worth flipping if auto-routing has been quietly spending your premium requests on trivial edits.