uuid

UUID - Universally Unique Identifiers

Trigger patterns: "UUID", "unique ID", "identifier", "v4", "v7", "uuidv4", "uuidv7"

Overview

UUID library for generating RFC9562-compliant unique identifiers in JavaScript/TypeScript applications.

Package: uuid@13.0.0
Standard: RFC9562 (formerly RFC4122)

Core Functions

1. v4() - Random UUID (Most Common)

Generates a version 4 UUID using cryptographically secure random values.

import { v4 as uuidv4 } from 'uuid';

// Generate random UUID
const taskId = uuidv4();
// '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'

// Use in entity creation
interface Task {
  id: string;
  title: string;
  createdAt: Date;
}

function createTask(title: string): Task {
  return {
    id: uuidv4(),
    title,
    createdAt: new Date()
  };
}

When to use:

• Entity IDs (tasks, users, blueprints)
• Session IDs
• Request tracking IDs
• File upload IDs
• Any unique identifier needs

2. v7() - Timestamp-based UUID (Sortable)

Generates a version 7 UUID with Unix epoch timestamp for natural chronological sorting.

import { v7 as uuidv7 } from 'uuid';

// Generate timestamp-based UUID
const orderId = uuidv7();
// '019a26ab-9a66-71a9-a89e-63c35fce4a5a'

// Multiple UUIDs are naturally sortable
const ids = Array.from({ length: 5 }, () => uuidv7());
// All IDs will be in chronological order

// Use for database primary keys
interface Order {
  id: string; // v7 UUID - sortable by creation time
  customerId: string;
  createdAt: Date;
}

When to use:

• Database primary keys requiring chronological sorting
• Event IDs in time-series data
• Log entry IDs
• Audit trail records
• Any scenario where temporal ordering matters

Advantages:

• Natural sort order by creation time
• Better database index performance
• Reduced fragmentation in B-tree indexes
• Compatible with UUID v4 in storage/APIs

Real-World Examples

Task Repository with UUID