# reply(_:) Sends a reply to the originator of the message. ``` func reply(_ object: Message) where Message : Encodable ``` ## Parameters `object` A message to send back to the client that sent the original message. ## Discussion When a listener receives an [`XPCReceivedMessage`](/documentation/XPC/XPCReceivedMessage), the message keeps track of the client that sent it. This function sends the specified reply message back to the originating client. Don’t call this function more than once on a single message, and don’t call it on a message that wasn’t received from a client. Calling it more than once or sending a reply using a message that wasn’t received triggers an API misuse crash. --- 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)