# express-mw-correlation-id Correlates HTTP requests between a client and server

[![Build Status](https://img.shields.io/badge/build-passing-brightgreen.svg?style=flat-square)](https://travis-ci.org/joaquimserafim/express-correlation-id)![Code Coverage 100%](https://img.shields.io/badge/code%20coverage-100%25-green.svg?style=flat-square)[![ISC License](https://img.shields.io/badge/license-ISC-blue.svg?style=flat-square)](https://github.com/joaquimserafim/express-correlation-id/blob/master/LICENSE)[![NodeJS](https://img.shields.io/badge/node-6.1.x-brightgreen.svg?style=flat-square)](https://github.com/joaquimserafim/express-correlation-id/blob/master/package.json#L48) [![JavaScript Style Guide](https://cdn.rawgit.com/feross/standard/master/badge.svg)](https://github.com/feross/standard) ### api `const setCorrelationId = require('express-mw-correlation-id')` **setCorrelationId([string, defaults to X-Request-ID], [formatter=identity]) * by default will use the `X-Request-ID` header but to use a custom header instead just pass the name in the first parameter * formatter is a function that will add custom formats to the generated ID, being, by default, the generated ID. * the middleware will reuse the request id if already present in the request headers **req.id** now is expose to be used internally by the api/service is using the `express-mw-correlation-id` middleware ### examples ```js const express = require('express') const setCorrelationId = require('express-mw-correlation-id') const app = express() app.use(setCorrelationId()) // `req.id` hold the correlation/request id app.get('/', (req, res) => { res.send(req.id) }) app.listen(3000) ``` #### Custom ID ```js app.use(setCorrelationId('X-Custom-ID')) ``` #### Custom ID and custom format ```js app.use(setCorrelationId('X-Custom-ID', (id) => id)) ``` #### Custom format ```js app.use(setCorrelationId((id) => id)) ``` client ```sh curl -v http://localhost:3000 * Rebuilt URL to: http://localhost:3000/ * Trying ::1... * Connected to localhost (::1) port 3000 (#0) > GET / HTTP/1.1 > Host: localhost:3000 > User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0) > Accept: */* > Referer: > < HTTP/1.1 200 OK < X-Powered-By: Express < X-Request-ID: 825efe65-a27d-4dca-936b-e74249095fb7 < Content-Type: text/html; charset=utf-8 < Content-Length: 11 < ETag: W/"b-sQqNsWTgdUEFt6mb5y4/5Q" < Date: Thu, 08 Dec 2016 10:22:44 GMT < Connection: keep-alive < * Connection #0 to host localhost left intact 825efe65-a27d-4dca-936b-e74249095fb7 ``` **X-Request-ID** should come with the headers ### ISC License (ISC)

express-mw-correlation-id

Downloads in past1 Month3 Months6 Months1 Year2 Years5 YearsAll time

Stats

Sick of boring JavaScript newsletters?

Downloads in past