Genepass v2.1.0

Generate a random customizable passwords

⚡ Zero dependencies. This library has NO runtime dependencies — nothing is pulled into your node_modules. It relies only on Node.js built-ins, keeping your install lean, fast and secure.

Security

Since v2.1.0, password generation is cryptographically secure. Requires Node.js >=14.10.0.

Every character is drawn uniformly from its full alphabet (no character is more or less likely than any other), and when more than one category is requested, how many characters come from each category is randomized too — not split evenly — so the category layout itself doesn't leak information.

Installation

Using npm

$ npm i --save genepass

JavaScript & TypeScript

Genepass works out of the box in both JavaScript and TypeScript projects. It's written in TypeScript and ships compiled CommonJS JS plus its own .d.ts type declarations — no @types/genepass package needed, and no extra setup required either way.

Usage

In Node.js

"length" of password generated must be defined, then "lowercase", "uppercase" or "number" must exists next to this.

const genepass = require('genepass');

const password = genepass.build({
    length: 12, // Required attribute
    lowercase: true,
    uppercase: true,
    number: true,
    special: true,
});

/**
 * Return example
 * password = "R@2lUO%i16x@"
 * /

Method chaining (fluent builder)

The same engine and validation rules are also available through a chainable API. Use whichever style fits your code better — both are fully interchangeable.

const genepass = require('genepass');

const password = genepass.create(12) // length, required attribute
    .lowercase()
    .uppercase()
    .number()
    .special()
    .build();

/**
 * Return example
 * password = "R@2lUO%i16x@"
 * /

genepass.Builder is also exported directly, so new genepass.Builder(12) works the same as genepass.create(12).

Supported attributes

Attribute	Data Type	Description	Required	Default
length	Number	Length of generated password, between 0 and 2048	true	-
lowercase	Boolean	At least one lowercase word in the generated password	false	false
uppercase	Boolean	At least one uppercase word in the generated password	false	false
number	Boolean	At least one number in the generated password	false	false
special	Boolean	At least one special character in the generated password. Could include: $, %, @, !, ?, #	false	false

Important

• length attribute is required
• It is necesary choose one of attribute apart of length.

Supported format examples

Return a combination lowercase uppercase password and 8 of length

const genepass = require('genepass');

const password = genepass.build({
    length: 8,
    lowercase: true,
    uppercase: true,
});
// or
const password = genepass.create(8)
    .lowercase()
    .uppercase()
    .build();

/**
 * Return example
 * password = "BzWuHBnb"
 * /

Return a PIN and 6 of length

const genepass = require('genepass');

const password = genepass.build({
    length: 6,
    number: true,
});
// or
const password = genepass.create(6)
    .number()
    .build();

/**
 * Return example
 * password = "875221"
 * /

Return a hard password

const genepass = require('genepass');

const password = genepass.build({
    length: 32,
    lowercase: true,
    uppercase: true,
    number: true,
    special: true,
});
// or
const password = genepass.create(32)
    .lowercase()
    .uppercase()
    .number()
    .special()
    .build();

/**
 * Return example
 * password = "h?bj1r1H1IIrm41nL?#@2T%?M@1LPg!1"
 * /

Common mistakes (throws RangeError)

const genepass = require("genepass");

// ❌ Missing "length"
genepass.build({ lowercase: true });
// or
genepass.create().lowercase().build();

// ❌ "length" out of range (must be between 0 and 2048)
genepass.build({ length: 2049, lowercase: true });
genepass.build({ length: -1, lowercase: true });

// ❌ "length" is not a number
genepass.build({ length: "12", lowercase: true });

// ❌ No character-type option selected (need at least one of
// "lowercase", "uppercase", "number" or "special")
genepass.build({ length: 10 });
// or
genepass.create(10).build();

Contributing

Want to contribute or understand how the project is built internally? See MAINTAINERS.md.