A MongoDB transport for winston

Usage no npm install needed!

<script type="module">
  import winstonMongodb from '';



A MongoDB transport for winston.

Current version supports only mongodb driver version 3.x and winston 3.x. If you want to use winston-mongodb with mongodb version 1.4.x use winston-mongodb <1.x. For mongodb 2.x use winston-mongodb <3.x.


tldr;?: To break the winston codebase into small modules that work together.

The winston codebase has been growing significantly with contributions and other logging transports. This is awesome. However, taking a ton of additional dependencies just to do something simple like logging to the Console and a File is overkill.


  var winston = require('winston');

   * Requiring `winston-mongodb` will expose
   * `winston.transports.MongoDB`

  winston.add(new winston.transports.MongoDB(options));

The MongoDB transport takes the following options. 'db' is required:

  • level: Level of messages that this transport should log, defaults to 'info'.
  • silent: Boolean flag indicating whether to suppress output, defaults to false.
  • db: MongoDB connection uri, pre-connected MongoClient object or promise which resolves to a pre-connected MongoClient object.
  • options: MongoDB connection parameters (optional, defaults to {poolSize: 2, autoReconnect: true, useNewUrlParser: true}).
  • collection: The name of the collection you want to store log messages in, defaults to 'log'.
  • storeHost: Boolean indicating if you want to store machine hostname in logs entry, if set to true it populates MongoDB entry with 'hostname' field, which stores os.hostname() value.
  • label: Label stored with entry object if defined.
  • name: Transport instance identifier. Useful if you need to create multiple MongoDB transports.
  • capped: In case this property is true, winston-mongodb will try to create new log collection as capped, defaults to false.
  • cappedSize: Size of logs capped collection in bytes, defaults to 10000000.
  • cappedMax: Size of logs capped collection in number of documents.
  • tryReconnect: Will try to reconnect to the database in case of fail during initialization. Works only if db is a string. Defaults to false.
  • decolorize: Will remove color attributes from the log entry message, defaults to false.
  • leaveConnectionOpen: Will leave MongoClient connected after transport shut down.
  • metaKey: Configure which key is used to store metadata in the logged info object. Defaults to 'metadata' to remain compatible with the metadata format
  • expireAfterSeconds: Seconds before the entry is removed. Works only if capped is not set.

Metadata: Logged as a native JSON object in 'meta' property.

Logging unhandled exceptions: For logging unhandled exceptions specify winston-mongodb as handleExceptions logger according to winston documentation.

Querying and streaming logs

Besides supporting the main options from winston, this transport supports the following extra options:

  • includeIds: Whether the returned logs should include the _id attribute settled by mongodb, defaults to false.


  $ npm install winston
  $ npm install winston-mongodb


Author: Charlie Robbins

Contributors: Yurij Mikhalevich, Kendrick Taylor, Yosef Dinerstein, Steve Dalby