How to Generate UUID in Node.js

Node.js UUID Evolution Timeline

Node.js < 14.17 Legacy

Third-Party Only

Required uuid npm package for UUID generation

npm install uuid

Node.js 14.17 - 15.x Transition

crypto.randomUUID() Introduced

Native UUID v4 generation added to crypto module

const { randomUUID } = require('crypto');

Node.js 16+ (Current) ✓ Recommended

Native UUID Standard

Stable crypto.randomUUID() with ES Modules support

import { randomUUID } from 'crypto';

Generate UUID with Native Node.js Crypto Module

✓ No Dependencies Required

Built into Node.js 14.17.0 and later. Zero npm packages needed! The python uuid reference shows how to use uuid.uuid4() as a Django model default without extra dependencies.

CommonJS

const { randomUUID } = require('crypto');

const uuid = randomUUID();
console.log(uuid);

ES Modules

import { randomUUID } from 'crypto';

const uuid = randomUUID();
console.log(uuid);

Async/Await UUID Generation Patterns

async-uuid.js

import { randomUUID } from 'crypto';

// Async function with UUID generation
async function createUser(name, email) {
    const userId = randomUUID();
    
    // Simulate database operation
    const user = {
        id: userId,
        name,
        email,
        createdAt: new Date().toISOString()
    };
    
    await saveToDatabase(user);
    return user;
}

// Generate multiple UUIDs asynchronously
async function generateBatchUUIDs(count) {
    const uuids = [];
    
    for (let i = 0; i < count; i++) {
        // Synchronous UUID generation in async context
        uuids.push(randomUUID());
    }
    
    return uuids;
}

// Usage
(async () => {
    const user = await createUser('Alice', '[email protected]');
    console.log('Created user:', user.id);
    
    const batchUuids = await generateBatchUUIDs(100);
    console.log(`Generated ${batchUuids.length} UUIDs`);
})();

Express.js Middleware: Request UUID Tracking

Automatic Request ID Generation

import express from 'express';
import { randomUUID } from 'crypto';

const app = express();

// Middleware: Add UUID to every request
app.use((req, res, next) => {
    req.id = randomUUID();
    res.setHeader('X-Request-ID', req.id);
    console.log(`[${req.id}] ${req.method} ${req.path}`);
    next();
});

// Route handler with request tracking
app.post('/users', async (req, res) => {
    const userId = randomUUID();
    
    console.log(`[${req.id}] Creating user with ID: ${userId}`);
    
    const user = {
        id: userId,
        ...req.body,
        createdAt: new Date()
    };
    
    res.json({ requestId: req.id, user });
});

app.listen(3000);

Advanced Logging with UUID Correlation

import winston from 'winston';
import { randomUUID } from 'crypto';

// Logger with correlation ID
const logger = winston.createLogger({
    format: winston.format.combine(
        winston.format.timestamp(),
        winston.format.json()
    ),
    transports: [new winston.transports.Console()]
});

// Middleware with structured logging
app.use((req, res, next) => {
    req.id = randomUUID();
    
    req.log = (level, message, meta = {}) => {
        logger.log({
            level,
            message,
            requestId: req.id,
            method: req.method,
            path: req.path,
            ...meta
        });
    };
    
    req.log('info', 'Request started');
    next();
});

UUID npm Package: All Versions Support

For UUID v1, v5, v6, and v7 support, install the uuid package: For cross-platform UUID generation in Flutter, the dart uuid guide covers iOS, Android, and web targets.

npm Package Installation

npm install uuid

uuid-all-versions.js

import { v1, v4, v5, v7, validate, version } from 'uuid';

// UUID v4 - Random (most common)
const uuidV4 = v4();
console.log('v4:', uuidV4);

// UUID v1 - Timestamp + MAC address
const uuidV1 = v1();
console.log('v1:', uuidV1);

// UUID v7 - Unix timestamp (sortable, database-optimized)
const uuidV7 = v7();
console.log('v7:', uuidV7);

// UUID v5 - SHA-1 hash (deterministic)
const NAMESPACE = '6ba7b810-9dad-11d1-80b4-00c04fd430c8';
const uuidV5 = v5('example.com', NAMESPACE);
console.log('v5:', uuidV5);

// Validate UUID
console.log('Valid:', validate(uuidV4));  // true

// Get version
console.log('Version:', version(uuidV4));  // 4

MongoDB Integration with UUID Primary Keys

mongodb-uuid.js

import { MongoClient } from 'mongodb';
import { randomUUID } from 'crypto';

const client = new MongoClient('mongodb://localhost:27017');

async function createUser(name, email) {
    await client.connect();
    const db = client.db('myapp');
    const users = db.collection('users');
    
    const user = {
        _id: randomUUID(),  // Use UUID instead of ObjectId
        name,
        email,
        createdAt: new Date()
    };
    
    await users.insertOne(user);
    console.log('Created user:', user._id);
    return user;
}

async function getUserById(uuid) {
    await client.connect();
    const db = client.db('myapp');
    
    return await db.collection('users').findOne({ _id: uuid });
}

Session Management with UUID Tokens

session-manager.js

import { randomUUID } from 'crypto';

class SessionManager {
    constructor() {
        this.sessions = new Map();
    }
    
    createSession(userId) {
        const sessionId = randomUUID();
        const expiresAt = Date.now() + (24 * 60 * 60 * 1000); // 24 hours
        
        this.sessions.set(sessionId, {
            userId,
            createdAt: Date.now(),
            expiresAt
        });
        
        return sessionId;
    }
    
    validateSession(sessionId) {
        const session = this.sessions.get(sessionId);
        
        if (!session) return null;
        if (Date.now() > session.expiresAt) {
            this.sessions.delete(sessionId);
            return null;
        }
        
        return session;
    }
    
    destroySession(sessionId) {
        return this.sessions.delete(sessionId);
    }
}

// Usage in Express
const sessionManager = new SessionManager();

app.post('/login', (req, res) => {
    const sessionId = sessionManager.createSession(req.body.userId);
    res.cookie('session', sessionId, { httpOnly: true });
    res.json({ sessionId });
});

Generate UUID in Node.js