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runmd.onRequire = path => {
  if (path == 'rng') return fun
  return path.replace(/^uuid/, './');
}

// Shim Date and crypto so generated ids are consistent across doc revisions
runmd.Date.prototype.getTime = () => 1551914748172;

let seed = 0xDEFACED;
require('crypto').randomBytes = function() {
  const a = [];
  for (let i = 0; i < 16; i++) a.push((seed = seed * 0x41a7 & 0x7fffffff) & 0xff);
  return a;
}

uuid Build Status

Simple, fast generation of RFC4122 UUIDS.

Features:

  • Support for version 1, 3, 4 and 5 UUIDs
  • Cross-platform
  • Uses cryptographically-strong random number APIs (when available)
  • Zero-dependency, small footprint (... but not this small)

[Deprecation warning: The use of require('uuid') is deprecated and will not be supported after version 3.x of this module. Instead, use require('uuid/[v1|v3|v4|v5]') as shown in the examples below.]

Quickstart - CommonJS (Recommended)

npm install uuid

Then generate your uuid version of choice ...

Version 1 (timestamp):

const uuidv1 = require('uuid/v1');
uuidv1(); // RESULT

Version 3 (namespace):

const uuidv3 = require('uuid/v3');

// ... using predefined DNS namespace (for domain names)
uuidv3('hello.example.com', uuidv3.DNS); // RESULT

// ... using predefined URL namespace (for, well, URLs)
uuidv3('http://example.com/hello', uuidv3.URL); // RESULT

// ... using a custom namespace
//
// Note: Custom namespaces should be a UUID string specific to your application!
// E.g. the one here was generated using this modules `uuid` CLI.
const MY_NAMESPACE = '1b671a64-40d5-491e-99b0-da01ff1f3341';
uuidv3('Hello, World!', MY_NAMESPACE); // RESULT

Version 4 (random):

const uuidv4 = require('uuid/v4');
uuidv4(); // RESULT

Version 5 (namespace):

const uuidv5 = require('uuid/v5');

// ... using predefined DNS namespace (for domain names)
uuidv5('hello.example.com', uuidv5.DNS); // RESULT

// ... using predefined URL namespace (for, well, URLs)
uuidv5('http://example.com/hello', uuidv5.URL); // RESULT

// ... using a custom namespace
//
// Note: Custom namespaces should be a UUID string specific to your application!
// E.g. the one here was generated using this modules `uuid` CLI.
const MY_NAMESPACE = '1b671a64-40d5-491e-99b0-da01ff1f3341';
uuidv5('Hello, World!', MY_NAMESPACE); // RESULT

API

Version 1

const uuidv1 = require('uuid/v1');

// Incantations
uuidv1();
uuidv1(options);
uuidv1(options, buffer, offset);

Generate and return a RFC4122 v1 (timestamp-based) UUID.

  • options - (Object) Optional uuid state to apply. Properties may include:

    • node - (Array) Node id as Array of 6 bytes (per 4.1.6). Default: Randomly generated ID. See note 1.
    • clockseq - (Number between 0 - 0x3fff) RFC clock sequence. Default: An internally maintained clockseq is used.
    • msecs - (Number) Time in milliseconds since unix Epoch. Default: The current time is used.
    • nsecs - (Number between 0-9999) additional time, in 100-nanosecond units. Ignored if msecs is unspecified. Default: internal uuid counter is used, as per 4.2.1.2.

  • buffer - (Array | Buffer) Array or buffer where UUID bytes are to be written.

  • offset - (Number) Starting index in buffer at which to begin writing.

Returns buffer, if specified, otherwise the string form of the UUID

Note: The default node id (the last 12 digits in the UUID) is generated once, randomly, on process startup, and then remains unchanged for the duration of the process.

Example: Generate string UUID with fully-specified options

const v1options = {
  node: [0x01, 0x23, 0x45, 0x67, 0x89, 0xab],
  clockseq: 0x1234,
  msecs: new Date('2011-11-01').getTime(),
  nsecs: 5678
};
uuidv1(v1options); // RESULT

Example: In-place generation of two binary IDs

// Generate two ids in an array
const arr = new Array();
uuidv1(null, arr, 0);  // RESULT
uuidv1(null, arr, 16); // RESULT

Version 3

const uuidv3 = require('uuid/v3');

// Incantations
uuidv3(name, namespace);
uuidv3(name, namespace, buffer);
uuidv3(name, namespace, buffer, offset);

Generate and return a RFC4122 v3 UUID.

  • name - (String | Array[]) "name" to create UUID with
  • namespace - (String | Array[]) "namespace" UUID either as a String or Array[16] of byte values
  • buffer - (Array | Buffer) Array or buffer where UUID bytes are to be written.
  • offset - (Number) Starting index in buffer at which to begin writing. Default = 0

Returns buffer, if specified, otherwise the string form of the UUID

Example:

uuidv3('hello world', MY_NAMESPACE);  // RESULT

Version 4

const uuidv4 = require('uuid/v4')

// Incantations
uuidv4();
uuidv4(options);
uuidv4(options, buffer, offset);

Generate and return a RFC4122 v4 UUID.

  • options - (Object) Optional uuid state to apply. Properties may include:
    • random - (Number[16]) Array of 16 numbers (0-255) to use in place of randomly generated values
    • rng - (Function) Random # generator function that returns an Array[16] of byte values (0-255)
  • buffer - (Array | Buffer) Array or buffer where UUID bytes are to be written.
  • offset - (Number) Starting index in buffer at which to begin writing.

Returns buffer, if specified, otherwise the string form of the UUID

Example: Generate string UUID with predefined random values

const v4options = {
  random: [
    0x10, 0x91, 0x56, 0xbe, 0xc4, 0xfb, 0xc1, 0xea,
    0x71, 0xb4, 0xef, 0xe1, 0x67, 0x1c, 0x58, 0x36
  ]
};
uuidv4(v4options); // RESULT

Example: Generate two IDs in a single buffer

const buffer = new Array();
uuidv4(null, buffer, 0);  // RESULT
uuidv4(null, buffer, 16); // RESULT

Version 5

const uuidv5 = require('uuid/v5');

// Incantations
uuidv5(name, namespace);
uuidv5(name, namespace, buffer);
uuidv5(name, namespace, buffer, offset);

Generate and return a RFC4122 v5 UUID.

  • name - (String | Array[]) "name" to create UUID with
  • namespace - (String | Array[]) "namespace" UUID either as a String or Array[16] of byte values
  • buffer - (Array | Buffer) Array or buffer where UUID bytes are to be written.
  • offset - (Number) Starting index in buffer at which to begin writing. Default = 0

Returns buffer, if specified, otherwise the string form of the UUID

Example:

uuidv5('hello world', MY_NAMESPACE);  // RESULT

Command Line

UUIDs can be generated from the command line with the uuid command.

$ uuid
ddeb27fb-d9a0-4624-be4d-4615062daed4

$ uuid v1
02d37060-d446-11e7-a9fa-7bdae751ebe1

Type uuid --help for usage details

Testing

npm test