Span API

Spans are measuring the duration of certain operations in an application. The topmost member of a span tree is called the root span. This span has no parent span and groups together its children with a representative name for the entire operation, such as GET / in case of a request to a backend application.

Creating a root span

The SDK must expose a method for creating a root span. The user must be able to set certain properties on this root span, such as its name, the type of operation (op) and others.

span = sentry.tracing.startSpan()
	->setName('GET /')
	->setOp('http.server')

span.end()

Creating nested spans

To create nested spans, the SDK must expose an explicit way for a user to perform this task.

Additionally, the SDK may expose alternative APIs to create nested spans, such as allowing a user to wrap an operation into a callback or apply a decorator to certain blocks. These alternative APIs must never create a root span and no-op if no parent span is present.

childSpan = span.startChild()
	->setName('authentication middleware')
	->setOp('middleware.handle')
	
childSpan.end()

Setting the span status

A span has two statuses, ok and error. By default, the status of a span is set to ok. The SDK must allow a user to modify the status of a span.

span.setStatus('error')

Setting span attributes

The SDK must expose a method to allow a user to set data attributes onto a span. These attributes should use pre-defined keys whenever possible.

span.setAttribute(SpanAttributes.HTTP_METHOD, 'GET')
span.setAttribute(SpanAttributes.HTTP_RESPONSE_STATUS_CODE, 200)

Receiving the trace parent

The SDK must expose a method to receive the baggage string.

traceparent = span.getTraceparent()

Receiving the baggage

The SDK must expose a method to receive the baggage string.

baggage = span.getBaggage()

Additional, optional span APIs

span.setStartTimestamp() - overwrite the span's start time span.setEndTimestamp() - overwrites the span's end time