# init(_:) Create a Framer protocol for use in a protocol stack. ``` init(@ProtocolStackBuilder _ builder: () -> BelowProtocol) where BelowProtocol : MessageProtocol ``` ## Parameters `builder` The protocol stack below Framer. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)