# nw_content_context_t A representation of a message to send or receive, containing protocol metadata and send properties. ``` typealias nw_content_context_t = any OS_nw_content_context ``` ## Discussion For sending, you should use `NW_CONNECTION_DEFAULT_MESSAGE_CONTEXT` unless there is a reason to override some values. You can pass `NW_CONNECTION_FINAL_MESSAGE_CONTEXT` to mark the final message in a connection. Once this context is used for sending, and the send is marked as complete, no more data can be sent on the connection. If you are using a protocol that expects message content, like WebSocket or a custom framer, create a custom context and set metadata using [`nw_content_context_set_metadata_for_protocol(_:_:)`](/documentation/Network/nw_content_context_set_metadata_for_protocol(_:_:)). ## Topics ### Creating Custom Send Contexts [`nw_content_context_create(_:)`](/documentation/Network/nw_content_context_create(_:)) Initializes a custom message context. [`nw_content_context_set_metadata_for_protocol(_:_:)`](/documentation/Network/nw_content_context_set_metadata_for_protocol(_:_:)) Sets protocol metadata to configure per-message or per-packet properties. [`nw_protocol_metadata_t`](/documentation/Network/nw_protocol_metadata_t) The abstract superclass for specifying metadata about a network protocol. [`nw_content_context_set_antecedent(_:_:)`](/documentation/Network/nw_content_context_set_antecedent(_:_:)) Set an optional message context that must be sent before the context you are sending. [`nw_content_context_copy_antecedent(_:)`](/documentation/Network/nw_content_context_copy_antecedent(_:)) Accesses the optional message context that must be sent before the context you are sending. [`nw_content_context_set_expiration_milliseconds(_:_:)`](/documentation/Network/nw_content_context_set_expiration_milliseconds(_:_:)) Sets the number of milliseconds after which sending the data associated with this context must begin, otherwise the data is discarded. [`nw_content_context_get_expiration_milliseconds(_:)`](/documentation/Network/nw_content_context_get_expiration_milliseconds(_:)) Accesses the expiration set for this message context. [`nw_content_context_set_relative_priority(_:_:)`](/documentation/Network/nw_content_context_set_relative_priority(_:_:)) Sets the relative value of priority used to reorder contexts when sending. [`nw_content_context_get_relative_priority(_:)`](/documentation/Network/nw_content_context_get_relative_priority(_:)) Accesses the relative value of priority used to reorder contexts when sending. [`nw_content_context_set_is_final(_:_:)`](/documentation/Network/nw_content_context_set_is_final(_:_:)) Sets a Boolean indicating if this context represents the final message being sent. [`nw_content_context_get_identifier(_:)`](/documentation/Network/nw_content_context_get_identifier(_:)) Accesses the identifier used to create this message context. ### Inspecting Receive Contexts [`nw_content_context_get_is_final(_:)`](/documentation/Network/nw_content_context_get_is_final(_:)) Checks whether this context represents the final message being received. [`nw_content_context_copy_protocol_metadata(_:_:)`](/documentation/Network/nw_content_context_copy_protocol_metadata(_:_:)) Retreives the metadata associated with a specific protocol. [`nw_content_context_foreach_protocol_metadata(_:_:)`](/documentation/Network/nw_content_context_foreach_protocol_metadata(_:_:)) Iterates through all protocol metadata associated with the message context. --- 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)