Instrumentation Libraries

How to use Swift instrumentation libraries

OpenTelemetry-Swift provides several instrumentation libraries that generate instrumentation for you when they’re installed and initialized.


SDKResourceExtension provides details about the device as a Resource.


Use DefaultResource.get() to generate an all-in-one resource object. This resource can be added to a TracerProvider or MetricProvider.

OpenTelemetry.registerTracerProvider(traceProvider: TracerProviderBuilder()
            .with(resource: DefaultResource.get())


SDKResourceExtension provides attributes in a resource object with details about the iOS device, OS details, and application details. It applies these values to the appropriate semantic attributes.

Application Info

AttributeValue exampleDescription
service.nameMyApplicationCFBundleName; The application name defined in the App’s info.plist.
service.version1.0 (1234)CFBundleShortVersion & (CFBundleVersion); The application version as defined in the App’s info.plist

Device Info

AttributeValue exampleDescription
device.model.identifieriphone13,3fetched from sysctl depending on device type
device.id00000000-0000-0000000identifierForVendor uuid string

Operating System Info

AttributesValue exampleDescription
os.typedarwinpredefined in ResourceAttributes
os.nameiOS, watchOS, macOSUIDevice.current.systemName or dependent on platform
os.descriptioniOS Version 15.4 (Build 19E240)A combination of os name, version and build.

NSURLSession Instrumentation

This instrumentation creates spans for all network requests made with NSURLSessions. It also injects distributed tracing headers in instrumented network requests. NetworkStatus is a dependency of this package, which provides network status attributes on network spans.


Initialize the class with URLSessionInstrumentation(configuration: URLSessionInstrumentationConfiguration()) to automatically capture all network calls.

This behavior can be modified or augmented by using the optional callbacks defined in URLSessionInstrumentationConfiguration:

  • shouldInstrument: ((URLRequest) -> (Bool)?)?

    Filter which requests you want to instrument, all by default.

  • shouldRecordPayload: ((URLSession) -> (Bool)?)?

    Implement if you want the session to record payload data, false by default.

  • shouldInjectTracingHeaders: ((URLRequest) -> (Bool)?)?

    Allow filtering which requests you want to inject headers to follow the trace, true by default. You must also return true if you want to inject custom headers.

  • injectCustomHeaders: ((inout URLRequest, Span?) -> Void)?

    Implement this callback to inject custom headers or modify the request in any other way.

  • nameSpan: ((URLRequest) -> (String)?)?

    Modify the name for the given request instead of standard OpenTelemetry name.

  • createdRequest: ((URLRequest, Span) -> Void)?

    Called after request is created, it allows to add extra information to the Span.

  • receivedResponse: ((URLResponse, DataOrFile?, Span) -> Void)?

    Called after response is received, it allows to add extra information to the Span.

  • receivedError: ((Error, DataOrFile?, HTTPStatus, Span) -> Void)?

    Called after an error is received, it allows to add extra information to the Span.

Below is an example of initialization. URLSessionInstrumentationConfiguration’s construction can be passed the parameters defined above to suit the needs of the application.

let sessionInstrumentation = URLSessionInstrumentation(URLSessionInstrumentationConfiguration())


NSURLSession instrumentation also provides additional attributes providing details about the network state of the device at the time of network requests.

AttributeValue exampleDescription, cell, unavailableThe type of connection utilized by the device at the time of the request. LTE, etcThey type of cellular connection. Only populated if the connection type is cell, Verizon, etcThe cellular carrier name. Only populated for cellular connection types. ISO 3166-1 alpha-2 2-character country code associated with the mobile carrier network. Country Code network code


This package creates os_signpost begin and end calls when spans are started or ended. It allows automatic integration of applications instrumented with OpenTelemetry to show their spans in a profiling app like Instruments. It also exports the OSLog it uses for posting so the user can add extra signpost events. This functionality is shown in Simple Exporter example


Just add SignpostIntegration as any other Span Processor (see the manual instrumentation) docs for details on configuring your providers: