SpanContext

import type { SpanContext } from 'dd-trace'

const ctx: SpanContext = span.context()

toTraceId(): string

const traceId = span.context().toTraceId()
console.log(traceId) // e.g. '1234567890abcdef1234567890abcdef'

toSpanId(): string

const spanId = span.context().toSpanId()
console.log(spanId) // e.g. 'abcdef1234567890'

toTraceparent(): string

const traceparent = span.context().toTraceparent()
console.log(traceparent)
// e.g. '00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01'

// Producer service: inject context into outgoing headers
const headers = {}
tracer.inject(span.context(), 'http_headers', headers)
await fetch('https://service-b/api', { headers })

// Consumer service: extract context from incoming headers
app.use((req, res, next) => {
  const parentContext = tracer.extract('http_headers', req.headers)
  const span = tracer.startSpan('http.request', { childOf: parentContext })
  // ...
})