Correlation IDs

import { correlationId } from '@axiljs/cloud'
 
app.use(correlationId())
 
app.get('/api/data', (req, res) => {
  console.log(req.locals.requestId)     // 'req_a1b2c3d4e5f6g7h8'
  console.log(req.locals.correlationId) // 'corr_x9y8z7w6v5u4t3s2'
  res.json({ data: '...' })
})

const response = await fetch('http://payment-service:3002/charge', {
  headers: {
    'X-Correlation-Id': req.locals.correlationId,
    'X-Request-Id': req.locals.requestId,
  },
})

app.use(correlationId({
  headerName: 'x-correlation-id',    // Incoming correlation header
  requestIdHeader: 'x-request-id',   // Incoming request ID header
  generateIfMissing: true,           // Auto-generate if not present
}))

import { Tracer, observabilityMiddleware } from '@axiljs/observability'
 
const tracer = new Tracer({ serviceName: 'my-api' })
 
app.use(correlationId())
app.use(observabilityMiddleware({ metrics, tracer }))
// Trace spans will include the correlation ID as an attribute