Request, response logger middleware using bunyan. Also provides request<>response duration.

Usage no npm install needed!

<script type="module">
  import bassettsjBunyanMiddleware from 'https://cdn.skypack.dev/@bassettsj/bunyan-middleware';



Dependency Status devDependency Status

npm install bunyan-middleware --save

Request, response logger middleware for bunyan:

  • log request as req
  • log response as res
  • log response close events as warnings
  • log request<>response duration in milliseconds as duration
  • creates, use and forward to response the x-request-id request header: get it if present, create it otherwise (uuid.v4())
  • log request id as req_id and exposes it as req.reqId
  • provides req.log and res.log as an id-specialized logger for you to track your request in your entire application, every time you access the request or response object
  • compatible with pure http server, express, connect and any http middleware system
  • uses serializers for req and res based on bunyan serializers if you do not already have a serializer defined.
  • obscure headers containing sensitive information in log outputs (configurable with obscureHeaders)


npm install bunyan-middleware --save


var bunyan = require('bunyan')
  , bunyanMiddleware = require('bunyan-middleware')
  , express = require('express')

var app = express()
var logger = bunyan.createLogger({ name: 'My App' })

    { headerName: 'X-Request-Id'
    , propertyName: 'reqId'
    , logName: 'req_id'
    , obscureHeaders: []
    , logger: logger

app.get('/', function (req, res) {
  // now use `req.log` as your request-specialized bunyan logger
  req.log.info('YO DAWG!')


Will use and forward X-Request-Id (case insensitive) header when present.

Otherwise it will generate a uuid.v4() and add it to the response headers.

The request id is also available as req.reqId.

Express and mounted apps

If you are using this with express and mounted app which rewrites req.url and you are using bunyan.serializers.req, then the url in the log output will be the rewritten url. To fix that bunyan-middleware is using its own request serializer instead of the default one which is using req.originalUrl instead.



  • The bunyan logger instance.

headerName Default: 'X-Request-Id'

  • The name of the HTTP header for the request id.

propertyName Default: 'reqId'

  • The name for the property on the request object to set the request id.

logName Default: 'req_id'

  • The name for the request id in the log output.

obscureHeaders Default: null

  • Set to an array with header nams to remove them from log output.

  • Eg: [ 'Authorization' ]

requestStart Default: false

  • Log the start of the request.

verbose Default: false

  • Log req and res for request start and request finish.


MIT. See the LICENCE file.

See Also