Apple has detailed a major change to its mobile platform: in Japan, users will be able to assign third-party voice assistants by holding down the side button on the iPhone. This new feature, explained in the developer documentation, opens the door to more flexible interaction with the device's hardware, something unprecedented in iOS.
Until now, holding down that button always activated Siri; with this feature, that action will be able to redirect to another compatible applicationAlthough availability will initially be limited to Japan, the move aligns with the regulatory direction in Europe and could eventually reach the European Union later.
How the side button remapping will work
The analysis of beta 3 of iOS 26.2 It had already pointed the way: the system incorporates references to an internal app called SystemVoiceAssistant and mentions of a “Side Button App” scheme to manage which assistant is activated by a long press. These findings point to a system router which decides which service takes control of the microphone and voice interface.
Among the system messages detected, the most notable were warnings about limitations by regionNotifications will be sent if the chosen app is no longer valid for the side button, and reminders will be sent that the configured app cannot be hidden or locked. In practice, iOS will ensure that the selected assistant is available and functioning correctly. operational at all times.
This is the first time the side button has not been exclusively linked to Siri, a change that, without altering other uses of the button (such as turning it on, off, or locking it), introduces a key customization in the iPhone experience.
Technical requirements for third-party apps
Apple explains that the integration is done through the framework App IntentsThe same platform that powers Shortcuts means developers will need to adapt their applications to ensure smooth activation when the button is pressed. The company outlines several essential technical steps to guarantee a seamless experience. instant and consistent:
- Declare capacity com.apple.developer.side-button-access.allow in the file of entitlements of the project.
- Create App Intent specify that defines the invocation of the assistant and its behavior upon startup.
- Implement the method perform() to take the user to the view from which the voice interaction begins.
- Start an audio session immediately (for example, with AVFoundation) so that the assistant responds instantly after pressing the button.
The developer guide also includes examples of architecture and best practices, emphasizing a minimal latency and in respect for the microphone permissions and user privacy.
Where and when it will be available
Apple indicates that the ability to remap the side button will be released exclusively in Japan in its first phase. Everything indicates that the region restriction will affect both the iPhone's configuration and the Apple ID account, avoiding the use of the function outside the country.
Although there is no official date, the changes seen in the system suggest a release with iOS 26.2The timing fits with the Japanese regulatory context, where a new competition law for mobile software is in place. It comes into effect in December 2025, forcing the opening of certain system functions to third parties.
In this phase, Japanese users will be able to choose between assistants such as Gemini, Alexa or ChatGPT —provided they meet the requirements— to respond when the side button is held down, replacing Siri in one of the most recognizable gestures of the iPhone.
What does this mean for the EU and for Spain?
La Digital Markets Law (DMA) European Union regulations stipulate that access gatekeepers must allow the selection of default applications and offer third parties equivalent access to key hardware and software functions. The opening of the side button aligns with this mandate and could facilitate its future deployment in the EUincluding Spain.
For now, Apple hasn't confirmed its arrival in Europe, but if it is enabled, users could opt for an alternative assistant that better suits their needs. domestic ecosystem or their work habits. This flexibility would increase competition among assistants and allow for greater personalization without relying solely on Siri.
Regarding privacy and security, strict controls are to be expected: Apple will predictably require explicit permissionsIt will manage microphone access and be able to impose usage limits to protect personal data. The balance between system openness and user protection will be key in any expansion of this feature within Europe.
If the experience proves successful in Japan, the initiative could become a inflection point For the iPhone: a physical button that lets the user choose which assistant to summon, with native integration, immediate response, and a common technical framework for all. For now, everything depends on the evolution of iOS 26.2, feedback from the first region, and how the [details of the announcements] are finalized. regulatory requirements in Europe.
Apple's plan introduces a significant change: the long press of the side button will no longer be the exclusive domain of Siri, at least in Japan, giving way to... third-party assistants integrated via App Intents and with instant response requirements; a controlled test that could anticipate relevant changes in Spain and the rest of the EU if the legal framework and technical implementation converge.
