1.0.0 • Public • Published


Anonymize values in an object based on property name patterns.

build status


npm install anonymize

Basic usage

Let's say you want to anonymize the environment variables so that passwords, tokens and other secrets are not exposed, in effect turning this:

  AWS_S3_SECRET: 'f6+ddWfgd2&dfbs3/dfgj&jkdbcds1234dsfgsss',
  NODE_ENV: 'production'

Into this:

  AWS_S3_SECRET: '******',
  DB_PASSWORD: '******',
  NODE_ENV: 'production'

You would simply:

var anonymize = require('anonymize')();
var anonEnv = anonymize(process.env);


You can control both the patterns used to match the properties and the replacement values.

By default properties containing the words secret, pass, auth or token have their values replaced with ****** The default patterns are case insensitive.

Both the patterns and the replacement value can be individually overridden by initializing the module with either an array of patterns or a replacement string (or an options hash containing both an array of patterns and a replacement value).

Override patterns

Create an anonymizer that replaces the value of any property whos name either contains foo or bar:

// ['foo', 'bar'] is equivalent to [/foo/i, /bar/i]
var anonymize = require('anonymize')(['foo', 'bar']);

Override replacement value

Create an anonymizer that replaces any property value with the string hidden:

var anonymize = require('anonymize')('hidden');

Override both patterns and replacement value

Combine both custom patterns and a custom replacement string:

var anonymize = require('anonymize')({
  patterns: ['foo', 'bar'],
  replace: 'hidden'

Delete matched properties

If the replacement value is undefined, the property will be deleted instead of having its value replaced.

Conditional replacement

If you instead of a string for the replacement use a function, you can control how a value is overwritten by conditionally returning the value that should be used for overwriting.

var anonymize = require('anonymize')({
  replace: function (key, val) {
    if (typeof val === 'number') return 0;
    return 'hidden';

Deeply nested objects

Yes, anonymize will also work on nested objects. So:

  foo: { password: 'secret' },
  bar: [ { token: 'secret' }]

Will be correctly anonymized to:

  foo: { password: '******' },
  bar: [ { token: '******' } ]



Package Sidebar


npm i anonymize

Weekly Downloads






Last publish


  • watson