# withIntervalSignpost(_:id:_:around:) Measures the execution of a closure and attaches the specified message. ``` func withIntervalSignpost(_ name: StaticString, id: OSSignpostID = .exclusive, _ message: SignpostMetadata, around task: () throws -> T) rethrows -> T ``` ## Parameters `name` The signpost’s name. `id` The signpost’s ID. The default value is [`exclusive`](/documentation/os/OSSignpostID/exclusive). `message` The interpolated string that the signposter attaches to the signpost. Each of the message’s interpolations can specify individual formatting and privacy options. For more information, see [Message Argument Formatters](/documentation/os/message-argument-formatters). `task` The closure around which to create the signposted interval. ## Discussion > Important: > Don’t create an instance of ``doc://com.apple.os/documentation/os/SignpostMetadata``. Instead, provide an interpolated string as the `message` parameter and the system converts it automatically. The signposter uses a signpost ID to pair the beginning and the end of a signposted interval, which is necessary because multiple intervals with the same configuration and scope can be in-flight simultaneously. If only one interval with a specific configuration can execute at any particular time, pass [`exclusive`](/documentation/os/OSSignpostID/exclusive) as the `id` parameter. Otherwise, use the [`makeSignpostID()`](/documentation/os/OSSignposter/makeSignpostID()) and [`makeSignpostID(from:)`](/documentation/os/OSSignposter/makeSignpostID(from:)) methods to generate a signpost identifier, as the following example shows: ```swift let accountNumber = "12345678" // Create a signposter using the default subsystem. let signposter = OSSignposter() // Generate a signpost ID to associate with the signpost. let signpostID = signposter.makeSignpostID() // Signpost the interval of a closure that encapsulates // one or more related tasks, and attach a message that // securely interpolates sensitive data. signposter.withIntervalSignpost("Account Reconciliation", id: signpostID, "Account: \(accountNumber, privacy: .sensitive(mask: .hash))") { // Perform the related tasks. processTransactions() updateBalance() } ``` --- 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)