# xpc_connection_set_peer_team_identity_requirement(_:_:) Sets a requirement that the executable for the peer process has a valid code signature and is signed by the same team identifier as the calling process. ``` func xpc_connection_set_peer_team_identity_requirement(_ connection: xpc_connection_t, _ signing_identifier: UnsafePointer?) -> Int32 ``` ## Parameters `connection` The XPC connection. `signing_identifier` The code-signing identifier for the peer process’s executable. This value is typically a Bundle ID for apps and extensions. Pass `NULL` to indicate that any binary signed by the same team as this process is acceptable. ## Return Value On success, `0`. Otherwise, a value from [Errors](/documentation/XPC/xpc-connections#Errors). ## Discussion When you set this requirement on a connection, the operating system checks that peer process satisfies the requirement every time it sends a message to your process. - If the peer process initiated the connection and its executable isn’t signed by the same team, or doesn’t have the correct signing identifier, then you don’t receive a message and the operating system doesn’t call your event handler. - If your process sent a message to its peer expecting a reply, and its executable isn’t signed by the same team, or doesn’t have the correct signing identifier, then you don’t receive a reply and the operating system delivers [`XPC_ERROR_PEER_CODE_SIGNING_REQUIREMENT`](/documentation/XPC/XPC_ERROR_PEER_CODE_SIGNING_REQUIREMENT-c.macro) instead. > Important: > Don’t call this function multiple times for the same connection, or call multiple functions that set code-signing requirements on the same connection. If you use either of these approaches, the system terminates your process with an error. --- 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)