[Announcement] Deprecation of PromiseKit in Swift 6 Generator

With the transition to Swift 6 and the maturity of native async/await, we suspect that PromiseKit usage within the generator has significantly declined.

To gauge community reliance on this integration and streamline the codebase, we are taking the following steps:

The Plan

• Deprecation: PromiseKit will be formally marked as deprecated in the next release. The deprecation warning will include a link leading back to this issue for context.

• Feedback Period: We are looking for community input. If your project still relies on PromiseKit integration within the Swift 6 generator, please leave a comment below explaining your use case.

• Timeline: If there is no significant feedback or objection by the end of 2026, we plan to permanently remove PromiseKit support in early 2027.

Why this change?

As Swift 6 emphasizes structured concurrency, maintaining legacy promise libraries increases maintenance overhead. We want to ensure the generator remains modern and efficient while still providing a window for users to transition their projects.

We value your feedback—please let us know if this change impacts your workflow!

Start with this issue, which requests community feedback about PromiseKit usage in the Swift 6 generator and proposes deprecation followed by possible removal. No implementation files, tests, or entry points are identified, and the completion criteria depend on feedback through the end of 2026.