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uuid Build Status

Simple, fast generation of RFC4122 UUIDS.

Features:

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

Quickstart - CommonJS (Recommended)

npm install uuid

Then generate your uuid version of choice ...

Version 1 (timestamp):

const uuidv1 = require('uuid/v1');
uuidv1(); // ⇨ 'af3da1c0-5cd9-11e7-8401-fb7c0283f80c'

Version 4 (random):

const uuidv4 = require('uuid/v4');
uuidv4(); // ⇨ 'f71c9fb3-2e34-46ee-bec3-d9baee2077ae'

Version 5 (namespace):

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

// ... using predefined DNS namespace (for domain names)
uuidv5('hello.example.com', uuidv5.DNS); // ⇨ 'fdda765f-fc57-5604-a269-52a7df8164ec'

// ... using predefined URL namespace (for, well, URLs)
uuidv5('http://example.com/hello', uuidv5.URL); // ⇨ '3bbcee75-cecc-5b56-8031-b6641c1ed1f1'

// ... 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); // ⇨ '630eb68f-e0fa-5ecc-887a-7c7a62614681'

Quickstart - Browser-ready Versions

Browser-ready versions of this module are available via wzrd.in.

For version 1 uuids:

<script src="http://wzrd.in/standalone/uuid%2Fv1@latest"></script>
<script>
uuidv1(); // -> v1 UUID
</script>

For version 4 uuids:

<script src="http://wzrd.in/standalone/uuid%2Fv4@latest"></script>
<script>
uuidv4(); // -> v4 UUID
</script>

For version 5 uuids:

<script src="http://wzrd.in/standalone/uuid%2Fv5@latest"></script>
<script>
uuidv5('http://example.com/hello', uuidv5.URL); // -> v5 UUID
</script>

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 | Date) 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 id is generated guaranteed to stay constant for the lifetime of the current JS runtime. (Future versions of this module may use persistent storage mechanisms to extend this guarantee.)

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); // ⇨ '710b962e-041c-11e1-9234-0123456789ab'

Example: In-place generation of two binary IDs

// Generate two ids in an array
const arr = new Array();
uuidv1(null, arr, 0);  // ⇨ [ 175, 62, 101, 16, 92, 217, 17, 231, 146, 52, 251, 124, 2, 131, 248, 12 ]
uuidv1(null, arr, 16); // ⇨ [ 175, 62, 101, 16, 92, 217, 17, 231, 146, 52, 251, 124, 2, 131, 248, 12, 175, 62, 140, 32, 92, 217, 17, 231, 146, 52, 251, 124, 2, 131, 248, 12 ]

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); // ⇨ '109156be-c4fb-41ea-b1b4-efe1671c5836'

Example: Generate two IDs in a single buffer

const buffer = new Array();
uuidv4(null, buffer, 0);  // ⇨ [ 18, 243, 219, 176, 63, 68, 75, 4, 191, 73, 152, 234, 209, 41, 234, 116 ]
uuidv4(null, buffer, 16); // ⇨ [ 18, 243, 219, 176, 63, 68, 75, 4, 191, 73, 152, 234, 209, 41, 234, 116, 91, 123, 222, 237, 118, 107, 76, 253, 134, 5, 17, 10, 186, 29, 236, 188 ]

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 v4 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:

// Generate a unique namespace (typically you would do this once, outside of
// your project, then bake this value into your code)
const uuidv4 = require('uuid/v4');
const uuidv5 = require('uuid/v5');
const MY_NAMESPACE = uuidv4();    // ⇨ '6e0aeafd-c8cd-4b8c-a1b2-91619e471280'

// Generate a couple namespace uuids
uuidv5('hello', MY_NAMESPACE);  // ⇨ '7e9e76e9-eab0-5365-82a6-b7de7ebb1675'
uuidv5('world', MY_NAMESPACE);  // ⇨ 'ba5e57dc-379d-53ba-9b8f-999185f40df2'

Command Line

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

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

Type uuid --help for usage details

Testing

npm test

Deprecated API

The API below is available for legacy purposes and is not expected to be available post-3.X

const uuid = require('uuid');

uuid.v1(...); // alias of uuid/v1
uuid.v4(...); // alias of uuid/v4
uuid(...);    // alias of uuid/v4

// uuid.v5() is not supported in this API

Legacy node-uuid package

The code for the legacy node-uuid package is available in the node-uuid branch.

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