UUID Generator Version 1 (V1)

Programming Examples

Each snippet below creates a version 1 UUID. Where the library allows it, you can also set the node and clock sequence yourself.

JavaScript

Install the package with npm install uuid. From version 12 on it is ES module only, so use import. By default it picks a random node, not your MAC address.

import { v1 as uuidv1 } from 'uuid';

console.log(uuidv1());

// Fixed node and clock sequence
console.log(
  uuidv1({
    node: Uint8Array.of(0x01, 0x23, 0x45, 0x67, 0x89, 0xab),
    clockseq: 0x1234,
  })
);

Python

The uuid module is builtZ in. Without arguments, uuid1() uses the machine’s hardware address when it can find one.

import uuid
from datetime import datetime, timedelta, timezone

u = uuid.uuid1()

# Read the creation time (100 ns ticks since 1582-10-15)
start = datetime(1582, 10, 15, tzinfo=timezone.utc)
created = start + timedelta(microseconds=u.time // 10)

print(u)
print(created.isoformat())

# Fixed node and clock sequence
print(uuid.uuid1(node=0x0123456789AB, clock_seq=1234))

Go

Add the package with go get github.com/google/uuid. NewUUID() returns a version 1 UUID, and SetNodeID() lets you fix the node.

package main

import (
	"fmt"

	"github.com/google/uuid"
)

func main() {
	id, err := uuid.NewUUID() // version 1
	if err != nil {
		panic(err)
	}
	fmt.Println(id)

	// Fixed node (first 6 bytes are used)
	uuid.SetNodeID([]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab})
	id2, _ := uuid.NewUUID()
	fmt.Println(id2)
}

Rust

In Cargo.toml, enable the v1, std and rng features: uuid = { version = "1", features = ["v1", "std", "rng"] }. Rust does not pick a node for you, so you pass a 6-byte one.

use uuid::Uuid;

fn main() {
    // You supply the 6-byte node yourself
    let node_id = [0x01, 0x23, 0x45, 0x67, 0x89, 0xab];
    let id = Uuid::now_v1(&node_id);
    println!("{}", id);
}

PHP

Install the library with composer require ramsey/uuid (PHP 8.0 or newer).

<?php

require 'vendor/autoload.php';

use Ramsey\Uuid\Uuid;

$uuid = Uuid::uuid1();

echo $uuid->toString() . PHP_EOL;
echo $uuid->getFields()->getVersion() . PHP_EOL;

MySQL

UUID() returns a version 1 value. The commands below are for quick copy and paste, since the reason for the swap flag is explained under Sorting and Databases.

SELECT UUID();

-- Swap the time parts for better index order
SELECT UUID_TO_BIN(UUID(), 1);

-- Convert it back to text
SELECT BIN_TO_UUID(UUID_TO_BIN(UUID(), 1), 1);

PostgreSQL

The uuid-ossp extension provides both functions. The v1mc version replaces the real MAC address with a random multicast node.

CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

SELECT uuid_generate_v1();

-- Random multicast node instead of the real MAC
SELECT uuid_generate_v1mc();