---
title: "xpc_session_set_incoming_message_handler(_:_:)"
framework: xpc
role: symbol
role_heading: Function
path: "xpc/xpc_session_set_incoming_message_handler(_:_:)"
---

# xpc_session_set_incoming_message_handler(_:_:)

Sets a handler to receive incoming messages for a session.

## Declaration

```swift
func xpc_session_set_incoming_message_handler(_ session: any OS_xpc_object, _ handler: @escaping xpc_session_incoming_message_handler_t)
```

## Parameters

- `session`: The session that receives messages.
- `handler`: A block that the session invokes when it receives messages.

## See Also

### Managing life cycle

- [xpc_session_activate(_:_:)](xpc/xpc_session_activate(_:_:).md)
- [xpc_session_cancel(_:)](xpc/xpc_session_cancel(_:).md)
- [xpc_session_set_cancel_handler(_:_:)](xpc/xpc_session_set_cancel_handler(_:_:).md)
- [xpc_session_incoming_message_handler_t](xpc/xpc_session_incoming_message_handler_t-elj.md)
- [xpc_session_cancel_handler_t](xpc/xpc_session_cancel_handler_t-65b6f.md)