Apple's Secret Siri Interface Buried in macOS 27 Beta: How to Enable

Apple appears to be testing a hidden popover interface for Siri AI in the macOS 27 Golden Gate beta that surfaces Writing Tools and contextual actions whenever the user selects some text.

Spotted by a member of Reddit's r/MacOSBeta community, the floating icon appears at the top-left of the selected text, expanding when the pointer hovers over it to a compact popover of the tools and actions.

Currently, the popover offers the tools Rewrite, Proofread, "How does this sound?" and "Edit with Siri," plus options for creating key points and summarizing text. The contextual actions are based on the content selected, including things like adding contact details, composing a message or email, creating a calendar event, showing a location in Maps, and tracking flights or packages.

The Siri popover is disabled by default in macOS 27 developer beta 3 and public beta 1. Beta testers found it can be switched on through a private feature flag, but the feature is clearly unfinished. Some of the actions don't respond, suggesting Apple is still building out the underlying functionality.

Adventurous beta users can try it with the following Terminal command, followed by a restart:
sudo mkdir -p /Library/Preferences/FeatureFlags/Domain && sudo defaults write /Library/Preferences/FeatureFlags/Domain/WritingTools LightweightUI_macOS -dict Enabled -bool true

And to disable the interface, use this command followed by a restart:
sudo defaults write /Library/Preferences/FeatureFlags/Domain/WritingTools LightweightUI_macOS -dict Enabled -bool false

Note that the UI's behavior is inconsistent, and there's no guarantee the interface will make it to the final release of macOS 27 Golden Gate this fall.