Apple flipped a switch yesterday that it had kept firmly in manual mode since Siri AI launched. Per the company’s own developer announcement, Siri AI is now open to all developers — not the short list of launch partners Apple hand-picked earlier in 2026, but anyone with Xcode and an Apple Intelligence-enabled device. The Developer Preview landed November 3 across the iOS 27.3, iPadOS 27.3, macOS 27.3, and visionOS 27.3 betas, and it’s the first time Apple has let outside developers wire their own apps directly into Siri’s reasoning layer instead of waiting for Apple to pick them.

This is a different Apple-Siri story than the ones we’ve been tracking all year. The Gemini-as-default procurement decision from WWDC was about which frontier lab powers Siri. The EU’s DMA block was about where Siri AI can even ship. This one’s about something narrower and, for a specific audience, more consequential: who gets to build the next thing Siri can do for a user, and what that costs them in code.

Quick Summary: What Happened

Detail	Info
Date	November 3, 2026
What shipped	Siri AI Developer Preview — open to all developers, no new entitlement required
Betas it’s in	iOS 27.3, iPadOS 27.3, macOS 27.3, visionOS 27.3
The core tool	New Swift macro @AppIntent(.tool) turns any custom App Intent into something Siri AI can call directly
New in this preview	Chaining (“Skills”) for multi-step requests, and Spotlight semantic-index lookups beyond fixed schemas
Developer labs	Online Apple Intelligence Group Labs, November 4–5, 2026
Customer release	”A few months” out, per Apple — widely expected with iOS 27.3’s public rollout in December 2026
App Store submissions	Open in spring 2027
Official source	developer.apple.com

Bottom line: Apple just took Siri AI integration from an invite-only partnership to an open SDK. The code works today. Your users won’t see it until next year.

What Actually Happened

Until this week, getting an app’s actions into Siri AI meant fitting inside one of roughly a dozen Apple-defined schema domains — Calendar-shaped things, Reminders-shaped things, Messages-shaped things. If your app didn’t look like one of those, Siri AI couldn’t touch it, full stop. That’s a real constraint. It’s also exactly the kind of gatekeeping that made Apple’s Extensions framework a procurement story for which model runs Siri, while the “which apps can Siri actually use” question stayed closed.

The Developer Preview removes the schema requirement entirely. The mechanism is a new Swift macro, @AppIntent(.tool), which you attach to a custom App Intent you’ve already written (or write fresh) to make it conform to a new ToolIntent protocol. Do that, and the intent becomes a tool Siri AI can call on its own — to pull content back (“what’s the status of my order”) or to take an action (“book the 7pm table,” “reorder the usual”). Per Apple’s documentation, intents that already match an existing Siri schema in a primary domain don’t need the annotation; this is specifically for everything that used to have no path in at all.

How Does Siri AI’s New App Intents System Actually Work?

1. You write or reuse an App Intent. If your app already has App Intents for Shortcuts or Spotlight, most of the plumbing exists.
2. You tag it @AppIntent(.tool). This is the one-line change that exposes the intent to Siri AI as a callable tool, conforming it to the new ToolIntent protocol.
3. You decide the scope. Apple’s own framing is explicit here: developers choose exactly what content Siri AI may retrieve and exactly what actions it’s allowed to perform. Nothing is exposed by default.
4. Siri AI calls it in context. A user’s plain-language request — “did my package ship yet” — gets matched to the right app’s tool without the user naming the app or opening it.
5. Multiple tools chain through a Skill. For anything that takes more than one step, a Skill (defined in a capped Markdown file, per Apple’s spec) teaches Siri AI how to sequence several tool calls into one interaction — check availability, then book, then confirm, as a single ask.
6. Content surfaces through Spotlight, too. Siri AI can now pull any entity already indexed in Spotlight’s semantic index, not just ones matching a predefined schema, which is a second, quieter way this preview widens what Siri can see.

That chaining piece is the part worth sitting with. A single @AppIntent(.tool) call gets you content retrieval or one action. Skills are what let a request like “check my deliveries and reschedule the one arriving Thursday” turn into an actual multi-step Siri AI interaction instead of three separate asks. Apple’s examples lean on exactly the use cases you’d expect from a shopping-and-logistics assistant: checking deliveries, booking reservations, placing orders.

Why This Matters

The headline framing — “Apple opens Siri to developers” — undersells how narrow the door used to be. Our WWDC 2026 coverage was about Apple handing enterprise IT a model choice between Gemini, ChatGPT, and Claude for Siri’s upstream reasoning. That’s an important decision, but it’s a decision about the brain, not the hands. The App Intents preview is about the hands: which apps Siri AI can actually reach into and operate, on a user’s behalf, without the user leaving the Siri conversation to open a separate app.

Up to now, that capability belonged to a curated set of launch partners Apple selected — the kind of integration where getting in required a relationship with Apple’s team, not just an Xcode project. This preview collapses that into something closer to how Apple normally treats its developer platforms: publish the API, document the macro, let anyone build against it, review what ships through the App Store review process everyone already knows. That’s a meaningfully different posture for a surface Apple has otherwise kept tightly controlled all year.

It’s also a bet that most AI assistant products eventually have to make. ChatGPT’s plugin and Actions ecosystem, Claude’s Model Context Protocol server directory, Gemini’s extensions — every serious conversational AI platform ends up concluding that the assistant is only as useful as the actions it can take in other people’s software, and that no single company can build all of those integrations itself. Apple just moved Siri AI from “we’ll decide who gets to be useful here” to “bring your own usefulness,” which is the same path the other platforms already took, on Apple’s own clock.

What Are Your Options Now

If you build iOS, iPadOS, macOS, or visionOS apps, there’s real work available to you starting today, with real limits on how far it goes before next year.

• Start with App Intents you already have. If your app ships Shortcuts actions or Spotlight-indexed content, you’re closer to a working @AppIntent(.tool) integration than a cold start. Add the macro, scope what Siri AI can see and do, and test against the betas.
• Register for the Apple Intelligence Group Labs. Apple is running online sessions on November 4 and 5, 2026, where its own engineers are answering implementation questions directly. For anyone building against a brand-new macro and protocol with sparse real-world examples, that’s the fastest way to avoid dead ends.
• Plan a Skill for anything multi-step. If your app’s useful Siri moment involves more than one action, a single tool intent won’t cover it. Scope the Skill file now so the sequencing logic exists before you’re racing a spring submission deadline.
• Don’t build your launch plan around December. Apple’s own language is “a few months” for customer release, which lines up with the iOS 27.3 public rollout widely expected in mid-December 2026 — but App Store submissions for Siri AI integrations don’t open until spring 2027. The preview is for building and testing now, not shipping to users yet.
• Read the terms before you commit scope. Apple has said it will follow up with specific terms and usage policies for experiences built on Siri AI as the preview matures. Build flexibly until those land.

The Bigger Picture

This preview lands in a year where Apple has treated Siri AI as three separate, slow-moving negotiations — one with Google over the Gemini license, one with the EU over the DMA, and, until now, essentially none with its own developer base over what Siri AI could actually do inside third-party apps. That last gap was the odd one out. Apple has spent two decades building one of the most developer-dependent platforms on earth, and for most of 2026 it ran Siri AI like a product with a short, Apple-approved partner list instead of a platform with an SDK.

Opening App Intents to everyone doesn’t resolve the other two negotiations. EU iPhone and iPad users still don’t get Siri AI at all, so a developer building a brilliant tool-call integration today has no path to EU users through this surface regardless of how good the code is. And the model choice question — Gemini by default, Claude or ChatGPT as the swap — sits one layer above the App Intents work entirely; whichever model is reasoning on a given device is the one deciding when and how to call a developer’s tool, which means app builders are now implicitly building for three different upstream reasoning styles depending on what the user, or their MDM administrator, picked.

The spring 2027 App Store gate is also worth reading as a deliberate choice, not a scheduling accident. Apple is giving developers a multi-month runway to build and break things in beta, in public, with direct engineer access through the Group Labs — and then closing the gap to shipping with a formal review step once the terms and usage policies it’s promised actually exist. That’s a more cautious rollout than “ship it and see,” which tracks with a company that spent much of 2026 being publicly pressed, in the EU fight especially, on exactly how much control third parties get over a system that sits this close to personal data and on-device context.

Our Take

I think this is the most developer-friendly thing Apple has done with Siri AI all year, and it’s overdue. Keeping deep Siri integration behind a curated partner list while simultaneously marketing Siri AI as a platform-level capability was always going to be a short-term posture — you can’t claim an assistant is genuinely useful across the app ecosystem while gatekeeping which apps get to participate. @AppIntent(.tool) is a small API surface, but removing the fixed-schema requirement is the part that actually changes what’s possible. That’s the difference between “Siri can do Calendar things” and “Siri can do whatever your app does, if you tell it how.”

Where I’d stay skeptical: a Developer Preview with no finalized terms, an unspecified daily usage cap, and a multi-month gap before anything ships to a real user is still, functionally, a beta for Apple as much as for developers. The chaining story — Skills turning several tool calls into one coherent multi-step interaction — is the genuinely new idea here, and it’s also the part with the least public testing behind it right now. Multi-step agentic behavior is hard to get right even for companies that have been building it for longer than a Developer Preview window. I’d build for this, I’d go to the Group Labs, and I would not promise a product manager a shipped Siri AI integration before spring 2027 — Apple hasn’t promised you one either.

Frequently Asked Questions

What is the Siri AI Developer Preview?

It’s Apple’s release, announced November 3, 2026, that opens Siri AI integration to any developer rather than a curated list of launch partners. It ships in the iOS 27.3, iPadOS 27.3, macOS 27.3, and visionOS 27.3 betas and requires no new entitlement to start building. (watchOS 27.3 gets Siri AI itself, but isn’t part of this App Intents Developer Preview.)

What does the @AppIntent(.tool) macro do?

It’s a Swift macro you attach to a custom App Intent to make it conform to a new ToolIntent protocol, which exposes that intent to Siri AI as a tool the assistant can call to retrieve content or perform an action. Intents that already match an existing Siri schema in a primary domain don’t need it.

Can Siri AI handle multi-step requests across several actions?

Yes, through what Apple calls Skills — developer-authored guidance, written as a capped Markdown file, that teaches Siri AI how to sequence multiple tool calls into a single interaction, like checking availability, booking, and confirming in one ask.

When can users actually use third-party Siri AI integrations?

Not yet. Apple says the new capabilities reach customers “in a few months,” which lines up with iOS 27.3’s public release widely expected around mid-December 2026. App Store submissions for Siri AI integrations don’t open until spring 2027, so no third-party integration can ship to the App Store before then.

Was Siri AI integration available to any developers before this?

Not in this open form. Deep Siri AI hooks were previously limited to a small set of Apple-selected launch partners working within a fixed set of schema domains. This preview is the first time any developer can build a Siri AI integration without that relationship or that schema constraint.

How do I get help building against the new App Intents system?

Apple is running online Apple Intelligence Group Labs on November 4 and 5, 2026, where developers can connect directly with Apple engineers about App Intents, Siri AI, and the Foundation Models framework. Registration and session times are on Apple’s developer news page.

Does this affect EU users?

Yes, by exclusion. Siri AI remains unavailable on iPhone and iPad in the EU under the DMA standoff, so any App Intents integration built through this preview has no path to those users regardless of how it’s built.

Does this change which AI model is reasoning behind Siri?

No. The App Intents preview is about which apps Siri AI can call into, not which model powers Siri’s reasoning. That’s a separate decision made at the Extensions layer, between Gemini, ChatGPT, and Claude.

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Last updated: November 4, 2026. Sources: Apple Developer — Siri AI is now open to all developers · Apple Developer documentation — App Intents Siri AI Developer Preview · ppc.land — Apple opens Siri AI to all developers, but apps can’t ship it until spring · TechRepublic — iOS 27.3 Coming in December.

Related reading: Apple WWDC 2026: Gemini Takes Over Siri · Apple’s Siri AI Blocked in EU: Enterprise Impact · iOS 27 Turns AI Tools Into a System Setting · Siri iOS 26.4 Review: Apple’s Gemini-Powered AI Overhaul · Vibe Coding in 2026: The Best Platforms for Building Apps