@cqrs-ddd/uuidv7

Generates and validates UUID version 7 identifiers as defined by RFC 9562. It has no runtime dependencies and no framework: it uses Node’s built-in crypto.randomBytes() only.

UUIDv7 puts a millisecond Unix timestamp in the leading bits, so identifiers created in different milliseconds sort by creation time as plain strings. That makes them a good fit for database primary keys, event identifiers and correlation IDs.

Installation

npm install @cqrs-ddd/uuidv7
# or
pnpm add @cqrs-ddd/uuidv7

Requires Node.js 22.12 or later.

Published as an ES module; a CommonJS application loads it with require().

API

import { isUuidV7, uuidv7 } from '@cqrs-ddd/uuidv7';

const id = uuidv7(); // e.g. '01923456-789a-7c3d-9e4f-0123456789ab'

isUuidV7(id); // true
isUuidV7(`  ${id}\n`); // true: surrounding whitespace is ignored
isUuidV7('00000000-0000-4000-8000-000000000000'); // false: version 4
isUuidV7(42); // false

Export	Signature	Description
uuidv7	() => string	A new UUIDv7 in the canonical lowercase 8-4-4-4-12 form
isUuidV7	(value: unknown) => value is string	true for a string that is a UUIDv7 once trimmed, in either case

Format guarantees

Each identifier is 128 bits, written as 36 lowercase hexadecimal characters and hyphens:

Bits	Field	Content
0–47	unix_ts_ms	Date.now(), the Unix time in milliseconds
48–51	ver	0111 (version 7)
52–63	rand_a	cryptographically random
64–65	var	10 (the RFC 9562 variant)
66–127	rand_b	cryptographically random

• Identifiers from different milliseconds sort by creation time when compared as strings.
• Identifiers from the same millisecond differ only in their random bits, so their order is random: this implementation does not add a monotonic counter.
• The timestamp comes from the system clock. If the clock moves backwards, later identifiers sort before earlier ones.
• isUuidV7 checks the textual form, the version and the variant. It does not check that the timestamp is plausible.

Examples

Validate an incoming identifier before using it, and generate one otherwise:

import { isUuidV7, uuidv7 } from '@cqrs-ddd/uuidv7';

function requestId(header: string | undefined): string {
  return isUuidV7(header) ? header.trim().toLowerCase() : uuidv7();
}

isUuidV7 accepts surrounding whitespace and uppercase, so normalize an accepted value before storing it if you compare identifiers as strings.

Read the creation time back from the first 48 bits:

import { uuidv7 } from '@cqrs-ddd/uuidv7';

const id = uuidv7();
const createdAt = new Date(Number.parseInt(id.replace(/-/g, '').slice(0, 12), 16));

License

Dual-licensed under AGPLv3 and a Commercial License. See the root LICENSE and COMMERCIAL_LICENSE.txt for details.