macOS 27 Golden Gate, launching this fall, is testing a revamped Mail app compose window that prominently features Apple Intelligence's Writing Tools and Siri AI. Discovered via feature flags in the latest beta, the new design places "Write with Siri" at the forefront, collapsing traditional formatting controls to the side.

The reworked bar also enables the preview of contextual Smart Reply suggestions from Siri AI before insertion. Once a suggested composition is chosen, options like "Edit with Siri," "Proofread," and "Rewrite" appear, with standard formatting tools minimized. This design allows users to interact with AI-generated text more fluidly.

Currently, the feature is not enabled by default and remains hidden behind an internal flag, indicating it's a work in progress. Bugs, such as the redesign only appearing when replying to emails in Beta 4, suggest further development is needed. If implemented, this integration aligns with Apple's broader strategy of incorporating Siri AI across its operating system, potentially launching alongside new iPhone 18 Pro models in September.