Last updated: September 15, 2026 · By Vishal Swami, Founder & Lead AI Reviewer, AISagely
Hidden framework code in the iOS 27 and macOS 27 ("Golden Gate") betas shows Apple has already built the plumbing to swap Siri for Claude or ChatGPT as your assistant's brain. None of it is switched on for regular users yet — the only third-party option that actually works today is the ChatGPT extension Apple shipped back in December 2024.
Short answer: You can't fully swap Siri for Claude or ChatGPT yet. Code in the iOS 27 and macOS 27 betas reveals two hidden mechanisms — Model Delegation and a Model Manager Services inference protocol — that let Claude or GPT-5.6 replace Siri's brain. Apple hasn't enabled either for the public; today only its official ChatGPT extension (since iOS 18.2) works.
I spend most of my working day moving between Claude, ChatGPT, and Gemini, so a report that Apple was quietly wiring Siri to talk to all three got my attention fast. The code itself was found by leaker "pdfu," who posted videos of Claude and GPT-5.6 running as Siri extensions on a beta build, and it was independently reported by MacRumors, 9to5Mac, and AppleInsider on September 14, 2026. In my testing on a public iOS 26 device (I don't have access to the unreleased iOS 27 beta pdfu used), none of that is reachable yet — which is the part worth being clear-eyed about before you go looking for a toggle that isn't there.
What you'll need
- An iPhone 15 Pro or newer (or a Mac with Apple silicon) running iOS 18.2 / macOS 15.2 or later, with Apple Intelligence turned on in Settings. That's the minimum for the one third-party option that's actually live: the ChatGPT extension.
- Five minutes and, optionally, a ChatGPT account. You don't need one — Apple lets you enable ChatGPT anonymously with a daily request limit, or sign in for higher limits and access to your paid plan's models.
- If you'd rather use Claude today, skip waiting on Apple and open Claude directly — the free tier covers everything the leaked demo showed it doing inside Siri, like drafting a reminder or a note.
- No developer beta required for anything in this guide. The Model Delegation entitlement pdfu found isn't public, so installing iOS 27 yourself won't unlock it.
Step-by-step: what actually works right now
1. Turn on Apple Intelligence
Go to Settings > Apple Intelligence & Siri and turn the feature on if you haven't already. This step alone takes a minute and is a prerequisite for every Siri extension, present or future.
2. Enable the ChatGPT extension
In the same settings screen, tap ChatGPT, then Set Up. Choose Enable ChatGPT to use it without an account, or Use ChatGPT with an existing account to sign in with OpenAI credentials, per Apple’s own setup guide. When I tested this flow, the whole setup took under two minutes and didn't require restarting the phone.
3. Ask Siri something ChatGPT can help with
Ask Siri a question it can't answer on its own — a "compose this in a more formal tone" request, a hard trivia question, or an image-analysis task — and Siri will offer to hand it to ChatGPT. You approve the handoff the first time; after that, Siri remembers your choice for similar requests. I found the confirmation prompt appeared for the first two or three handoffs, then stopped showing up for the same type of request.
4. Turn off the confirmation prompt if it gets repetitive
Back in Settings > Apple Intelligence & Siri > ChatGPT, toggle Confirm ChatGPT Requests off if you'd rather Siri route eligible questions to ChatGPT automatically, no approval tap needed. For a full walkthrough of everything this extension can do beyond Siri, see my ChatGPT on iPhone guide.
5. Watch for Claude and Model Delegation — don't expect them yet
The two mechanisms pdfu found are Model Delegation, an App Intents API that lets an app like Claude register as a Siri extension the same way ChatGPT already does, and a separate Model Manager Services inference protocol that can replace Siri's entire server-side model with something like GPT-5.6, bypassing Siri's own reasoning altogether. Both exist in the iOS 27 and macOS 27 code. Neither has a public entitlement, so no combination of settings, betas, or developer accounts turns them on today.
Example prompts you can copy
With the ChatGPT extension enabled, these are worth trying:
- "Hey Siri, ask ChatGPT to rewrite this text message so it sounds less blunt."
- "Hey Siri, ask ChatGPT what the difference is between compound and simple interest."
- "Hey Siri, ask ChatGPT to summarize the plot of [a book or movie] without spoilers."
If you're using Claude or ChatGPT directly instead of waiting on Siri integration, these get you most of the same value:
- "Read this email thread and draft a two-sentence reply that confirms the meeting time and asks for the agenda."
- "Turn this list of errands into a checklist grouped by location."
- "I'm about to ask Siri to set a reminder — here's the messy version of what I need reminded about; clean it up into one sentence."
Common mistakes to avoid
The biggest mistake is assuming Claude already works inside Siri because you saw a demo video — it doesn't, for anyone, on any released software. Second is confusing this leak with Apple's separate, already-confirmed Gemini deal: Apple is paying Google roughly $1 billion a year for a custom Gemini model that powers the revamped, more conversational Siri rolling out through iOS 27, according to MacRumors’ April 2026 reporting. Model Delegation is a different, still-hidden layer for swapping in outside assistants like Claude on top of that. Third is installing the iOS 27 beta expecting extra options — the entitlement isn't flipped on for anyone outside Apple. Fourth is turning on the ChatGPT extension and expecting it to replace Siri for every request; it only activates for queries Siri decides it can't handle, or when you explicitly say "ask ChatGPT." Fifth is approving the handoff without reading what it means: each request sent to ChatGPT leaves your device and reaches OpenAI, which is exactly why Apple asks permission the first few times.
Tools that make this easier
You don't have to wait on Apple to get an AI assistant that talks to more than one model. If you're deciding whether ChatGPT or Claude is the better daily driver while this feature sits in beta limbo, my Claude vs. ChatGPT comparison covers where each one wins. For getting Claude set up on its own, independent of Siri, how to use Claude AI walks through the basics. Since Siri's own backend is quietly running on Google's model already, Gemini vs. ChatGPT is worth a look too. My best AI models roundup compares all three at once if you want the full picture, and free AI tools is where to start if you don't want to pay for anything yet. If you'd rather talk to Siri's replacements out loud instead of typing, how to use ChatGPT voice covers Advanced Voice Mode, which already feels closer to what Model Delegation is reportedly aiming for.
My take
Apple building this plumbing doesn't surprise me — regulators in the EU have been pushing Apple toward exactly this kind of interoperability, and a 9to5Mac reader poll found about 81% of respondents wanted the option to pick a different AI assistant than Siri, with only 6% firmly opposed. What I'd push back on is treating a beta code leak as a roadmap. Apple has shipped exactly one third-party model integration in the eighteen months since iOS 18.2 — ChatGPT — and took its time doing it. I'd bet on Claude and GPT-5.6 support arriving the same cautious way, likely gated behind the same kind of regional rules that shaped Apple's other DMA-driven changes, not as a flip-a-switch feature in the next point release.
Frequently Asked Questions
Can I use Claude with Siri right now?
No. Claude has only been demonstrated running as a Siri extension in an unreleased iOS 27 beta by a code researcher, not shipped to any user. Today, Claude only works as its own separate app.
What is Model Delegation?
It's an App Intents mechanism found in the iOS 27 and macOS 27 code that lets a third-party app register itself as a Siri extension, similar to how the built-in ChatGPT extension already works. Apple has not opened it to outside developers.
Is Siri already powered by Google's Gemini?
Yes, partly. Apple's revamped, more conversational Siri — rolling out in phases through iOS 27 — runs on a custom Gemini model under a reported multi-year deal with Google. That's separate from the Claude/ChatGPT swapping shown in this leak.
How do I turn on ChatGPT for Siri today?
Go to Settings > Apple Intelligence & Siri > ChatGPT > Set Up, then choose to use it with or without an OpenAI account. It requires an iPhone 15 Pro or newer, or an Apple silicon Mac, with Apple Intelligence enabled.
Will Apple let me pick any AI model for Siri eventually?
Nothing is confirmed. The code shows Apple engineered for that possibility, and EU rules may push it further, but Apple hasn't announced a timeline or said which models beyond its own and Google's Gemini it would allow.