iOS 27 Siri Extensions: Choose Gemini, Claude, or ChatGPT

Extensions Ends ChatGPT Exclusivity

Apple is building Siri Extensions into iOS 27, iPadOS 27, and macOS 27 — a framework that lets users choose which AI model powers Siri, Writing Tools, and Image Playground. The options at launch: Gemini, Claude, ChatGPT, and any third-party provider who ships a compatible app through the App Store. WWDC 2026 on June 8 is where Apple will lay out the full technical picture.

This ends the arrangement Apple established in iOS 18, where ChatGPT was the single external model Siri could delegate to. iOS 27 turns that into an explicit user preference. Install the AI provider’s iOS app, enable its Extension in Settings, and that model becomes the default reasoning engine across all three Apple Intelligence surfaces simultaneously — one setting, three surfaces.

The distribution mechanism matters. Apple is not opening an API endpoint. Extensions are gated through the App Store, which means in-app purchases, subscription management, and review all apply. AI providers gain system-level reach on iOS in exchange for running through Apple’s standard storefront rails.

How This Sits on Top of App Intents

Siri Extensions is not a replacement for App Intents — it is a layer above it. App Intents remains the mechanism by which your app exposes discrete actions to the system: search for an order, book a ride, play a specific track. Extensions changes which model interprets those intents when a user invokes Siri.

In iOS 26, when a user asks Siri to “book a table for two at 8pm” and your restaurant app has implemented the relevant App Intents domain, Apple’s on-device model resolves the request and calls your app’s intent. In iOS 27, if the user has set Claude as their Extensions default, Claude interprets that query and invokes your intent handler.

The practical implication: the quality of your intent schemas matters more than it did. Well-typed parameters, descriptive entity identifiers, and accurate intent metadata improve the probability that any model — not just Apple’s — routes the query correctly to your app. If you shipped App Intents on the assumption that only Apple’s model would parse them, that assumption expires this fall.

The Gemini Deal Is a Separate Layer

Extensions gives users a choice menu. The Apple-Google partnership is what runs underneath it.

Google confirmed in April a reported $1 billion-per-year deal to power a more personalized Siri arriving later in 2026. This is the infrastructure layer — the model handling Apple Intelligence for users who haven’t selected a custom Extension. When most people ask Siri a question without touching Settings, they’re talking to Gemini.

The distinction between the infrastructure deal and the Extensions framework is worth holding onto. Apple is simultaneously betting on one external AI provider at the system level and building a choice mechanism above it, likely in part to satisfy EU Digital Markets Act requirements. Whatever the regulatory driver, the result is the same: Apple no longer controls its own AI reasoning layer, and it has two separate contracts — one with infrastructure, one with storefront distribution — to prove it.

What This Means for App Developers

Two scenarios worth separating before WWDC ships the full API:

AI is a supporting feature in your app — summarization, smart search, a drafting assistant, semantic filters. For these apps, Extensions reinforces the case for deeper App Intents investment. The more naturally your app surfaces via Siri, the more useful it becomes in a world where users reach for their system AI first rather than opening a separate app. If you haven’t implemented App Intents domains relevant to your app’s category, the window for that work is now.

AI is your app’s core product — a conversational assistant, a writing tool, a domain-specific AI agent. This is where Extensions creates real competitive pressure. Your in-app AI feature and the user’s system-level Claude or Gemini are now competing for the same invocation moment. Users who’ve set a preferred model have Siri one phrase away; they’re less likely to tap into a separate app UI.

The response isn’t to compete on general AI capability — you won’t win on compute against models trained at that scale. It’s to go deeper on what your app uniquely knows: proprietary data, specialized context, domain actions the system model cannot access. For the kinds of healthcare and fintech apps we build, where AI needs access to structured user data and has to operate within compliance constraints, vertical depth beats general breadth decisively. A system-level Gemini has no access to your user’s claims history or lab results. Your app does.

Two Open Questions Before June 8

The technical picture from search results and reports is consistent in broad strokes, but two details will determine how significant this actually is for most developers:

Breadth of partner access. Does Apple open Extensions to any App Store app meeting a technical specification, or is the initial launch restricted to a small set of approved providers — Gemini, Claude, ChatGPT, and maybe a handful of others? If it’s open, any sufficiently capable AI product can compete for system-level default status on iOS. If restricted, it’s mainly a DMA compliance mechanism dressed as a platform feature.

Action scope parity. Does a third-party Extensions model get the same App Intents invocation scope that Apple’s own model has, or does it receive a reduced surface? Apple has historically kept the most sensitive action domains — payment flows, Health data, secure credentials — gated. If third-party models can invoke the full App Intents domain set, Extensions meaningfully shifts the integration surface. If they can’t, the choice is cosmetic for most queries.

The WWDC App Intents and Siri Engineering sessions will answer both. We’ll be watching them closely. If you’re planning an iOS AI integration before fall and want to think through the architecture ahead of the beta, get in touch.

Sources

1. iOS 27 will let you choose between Gemini, Claude, and more for AI features — 9to5Mac, May 5 2026
2. With iOS 27, Apple may open Siri and AI features to third-party models — Business Standard, May 6 2026
3. Google Confirms Gemini-Powered Siri Coming Later This Year — MacRumors, April 22 2026
4. Apple Lets Gemini, and Claude in iOS 27, Will End ChatGPT Exclusivity — Trending Topics, May 2026
5. Integrating actions with Siri and Apple Intelligence — Apple Developer Documentation