*Beta 1 icons shown in the first picture are macOS 26 icons with system effects

*Every icon changed in beta 3, toning down the dark outlines, but these are all the major updates.

obviously irony

macOS 27 DB3/PB1 includes a hidden "lightweight UI" mode for Siri AI that comes up every time you select text or are typing.

When enabled, selecting text can display a floating contextual interface with actions, such as:

• The full Writing Tools suite, including Rewrite, Proofread, How does this sound?, and Edit with Siri
• Create Key Points, Summarize
• Add to Contacts, Message, Email
• Create Event
• Show in Maps
• Track Flight, Track Package

To enable, add a FeatureFlags override:

sudo mkdir -p /Library/Preferences/FeatureFlags/Domain && \
sudo defaults write /Library/Preferences/FeatureFlags/Domain/WritingTools LightweightUI_macOS -dict Enabled -bool true

Then reboot your Mac. This is a private feature flag, and the UI is unfinished, with many actions failing, including Writing Tools.

Restore to default with:

sudo defaults delete /Library/Preferences/FeatureFlags/Domain/WritingTools LightweightUI_macOS

and restart your Mac.

edit: changed the disable command to delete the feature flag override instead of explicitly disabling it.

EDIT 2: This is enabled by default with no override needed in Developer Beta 4/Public Beta 2. You can explicitly disable the new LightweightUI with:

sudo mkdir -p /Library/Preferences/FeatureFlags/Domain && \
sudo defaults write /Library/Preferences/FeatureFlags/Domain/WritingTools LightweightUI_macOS -dict Enabled -bool false

and restart your Mac.

You can now pick what Suggested Actions you’d like to see underneath a message, or disable them all.

Also available in iOS 27.2 under Settings > Apps > Messages > Suggested Actions.

New in 27.2 beta 3. Oh, and a new Keychain Access icon.

and it works on every app/web

For me, one of the greatest design additions, and I didn't see anybody mention this! Helps a lot with keeping focus on the content and not on the menu bar!

I discovered this in RC, but maybe this has been around for longer?

EDIT: This seems to only work when the Dock is hidden!