# XPCSession A type that sends messages to a server process. ``` class XPCSession ``` ## Overview XPC sessions are stateful connections you use to send structured messages to a separate process. Once established, a session remains active until one side of the connection cancels it, at which point the system invalidates the connection. ## Topics ### Creating a session [`init(xpcService:targetQueue:options:incomingMessageHandler:cancellationHandler:)`](/documentation/XPC/XPCSession/init(xpcService:targetQueue:options:incomingMessageHandler:cancellationHandler:)-407h2) Establishes a connection to an XPC service with the name and decodable message handler you specify. [`init(xpcService:targetQueue:options:incomingMessageHandler:cancellationHandler:)`](/documentation/XPC/XPCSession/init(xpcService:targetQueue:options:incomingMessageHandler:cancellationHandler:)-9f4u0) Establishes a connection to an XPC service with the name and received message handler you specify. [`init(xpcService:targetQueue:options:incomingMessageHandler:cancellationHandler:)`](/documentation/XPC/XPCSession/init(xpcService:targetQueue:options:incomingMessageHandler:cancellationHandler:)-bel3) Establishes a connection to an XPC service with the name and dictionary message handler you specify. [`init(xpcService:targetQueue:options:cancellationHandler:)`](/documentation/XPC/XPCSession/init(xpcService:targetQueue:options:cancellationHandler:)) Establishes a connection to an XPC service with the name you specify. [`init(machService:targetQueue:options:incomingMessageHandler:cancellationHandler:)`](/documentation/XPC/XPCSession/init(machService:targetQueue:options:incomingMessageHandler:cancellationHandler:)-l3rz) Establishes a connection to a launch agent or launch daemon with the name and decodable message handler you specify. [`init(machService:targetQueue:options:incomingMessageHandler:cancellationHandler:)`](/documentation/XPC/XPCSession/init(machService:targetQueue:options:incomingMessageHandler:cancellationHandler:)-2xuyi) Establishes a connection to a launch agent or launch daemon with the name and received message handler you specify. [`init(machService:targetQueue:options:incomingMessageHandler:cancellationHandler:)`](/documentation/XPC/XPCSession/init(machService:targetQueue:options:incomingMessageHandler:cancellationHandler:)-6jz7y) Establishes a connection to a launch agent or launch daemon with the name and dictionary message handler you specify. [`init(machService:targetQueue:options:cancellationHandler:)`](/documentation/XPC/XPCSession/init(machService:targetQueue:options:cancellationHandler:)) Establishes a connection to a launch agent or launch daemon with the name you specify. [`XPCSession.InitializationOptions`](/documentation/XPC/XPCSession/InitializationOptions) Options that control the session’s configuration. [`setTargetQueue(_:)`](/documentation/XPC/XPCSession/setTargetQueue(_:)) Sets the target dispatch queue on an inactive session for processing messages. ### Managing the life cycle [`activate()`](/documentation/XPC/XPCSession/activate()) Activates a session so you can send messages. [`setIncomingMessageHandler(_:)`](/documentation/XPC/XPCSession/setIncomingMessageHandler(_:)-2ukdh) Sets a closure to receive incoming decodable messages for a session. [`setIncomingMessageHandler(_:)`](/documentation/XPC/XPCSession/setIncomingMessageHandler(_:)-5lu26) Sets a closure to receive incoming received messages for a session. [`setIncomingMessageHandler(_:)`](/documentation/XPC/XPCSession/setIncomingMessageHandler(_:)-75ou9) Sets a closure to receive incoming dictionary messages for a session. [`cancel(reason:)`](/documentation/XPC/XPCSession/cancel(reason:)) Cancels a session, discarding any unsent messages. [`setCancellationHandler(_:)`](/documentation/XPC/XPCSession/setCancellationHandler(_:)) Sets a closure the session calls when it’s canceled. ### Sending messages [`send(_:)`](/documentation/XPC/XPCSession/send(_:)) Sends an encodable message over the session to the destination service. [`send(_:replyHandler:)`](/documentation/XPC/XPCSession/send(_:replyHandler:)-3wjln) Sends an encodable message over the session to the destination service, using the closure you specify to handle a reply and rich error. [`send(_:replyHandler:)`](/documentation/XPC/XPCSession/send(_:replyHandler:)-9an0u) Sends an encodable message over the session to the destination service, using the closure you specify to handle a reply. [`send(message:)`](/documentation/XPC/XPCSession/send(message:)) Sends a dictionary message over the session to the destination service. [`send(message:replyHandler:)`](/documentation/XPC/XPCSession/send(message:replyHandler:)) Sends a message asynchronously over the session to the destination service, calling a closure after receiving a reply. [`sendSync(_:)`](/documentation/XPC/XPCSession/sendSync(_:)-8a284) Sends an encodable message over the session to the destination service, blocking the caller until receiving a reply message. [`sendSync(_:)`](/documentation/XPC/XPCSession/sendSync(_:)-88u0s) Sends an encodable message over the session to the destination service, blocking the caller until receiving an encodable reply message. [`sendSync(message:)`](/documentation/XPC/XPCSession/sendSync(message:)) Sends a dictionary message over the session to the destination service, blocking the caller until receiving a reply. --- 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)