Apple opens Siri to Claude, ChatGPT, and Gemini as iOS 27 Extensions reshape the iPhone AI stack

At WWDC 2026, Apple unveiled a rebuilt 'Siri AI' powered by a custom 1.2-trillion-parameter Google Gemini model and introduced an Extensions framework letting users set rival assistants as the iPhone default.

Apple announced at WWDC 2026 on Monday that it’s paying Google roughly $1 billion a year for a custom 1.2-trillion-parameter Gemini model to power a rebuilt Siri AI, and that iOS 27 will, for the first time, let iPhone users set Claude or ChatGPT as the system assistant through a new Extensions framework. The two announcements, taken together, mark the end of Apple’s decade-long pretense that it could build the assistant layer alone.

The architecture has 3 tiers. On-device Apple Foundation Models handle the simplest queries, Private Cloud Compute handles the middle, and the hosted Gemini model handles anything heavy. Bloomberg’s Mark Gurman reported the billion-dollar figure and the routing details; The Next Web mapped the tiering. Apple’s own newsroom language is careful, saying it “collaborated with Google and the Gemini family of models to develop the next generation of Apple Foundation Models.”

That phrasing is narrative management. The model isn’t Apple’s. The check is.

Siri AI itself is, per Engadget reporting live from Apple Park, the biggest update to the assistant since its original rollout more than a decade ago: personal-context search across messages, emails, and photos; multi-step commands; on-screen questions; actions in third-party apps. There’s also a standalone Siri app with an iMessage-style chat interface across iPhone, iPad, and Mac.

The Extensions framework is the more structurally telling move. Siri remains the default in system Search or Ask, but users can swap in Anthropic’s Claude or OpenAI’s ChatGPT. The Next Web frames this as a concession to competitive pressure and to the EU’s Digital Markets Act, which had previously forced Apple to pause parts of its AI rollout in Europe. Either way, the walled garden now has a side door explicitly labeled for rivals.

Context matters here. Last month Apple settled a $250 million consumer class action over Siri AI features it marketed in 2024 when the iPhone 16 shipped but couldn’t deliver. Developer betas went out Monday, public betas land in July, and general release arrives in autumn alongside new iPhone hardware. On September 1, Tim Cook hands the CEO role to hardware chief John Ternus. This was his final WWDC, and the keynote it produced was an admission that the iPhone’s most-marketed software layer now runs on someone else’s weights.

Apple opens Siri to Claude, ChatGPT, and Gemini as iOS 27 Extensions reshape the iPhone AI stack

Sources