express-guard

Validation, Sanitization & Error Handling Kit for Express.js

express-guard is a lightweight, modern, TypeScript-first package that minimizes validation and error-handling boilerplate in Express applications.

Features

• Powerful request validation powered by Zod
• Centralized error handler with standardized JSON responses
• Custom error classes (ValidationError, AppError)
• Full TypeScript support with strong type inference
• Automatic data transformation after validation
• Debug mode for development
• Lightweight and performant

Installation

pnpm add express-guard
# or
npm install express-guard

creat Guard:

import express from 'express'; import { createGuard } from 'express-guard'; import { z } from 'zod';

const app = express(); const guard = createGuard({ debug: true, // Enable debug logs in development validationErrorStatus: 422 // Default validation error status code });

app.use(express.json());

Use validation:

const createUserSchema = z.object({ name: z.string().min(3, "Name must be at least 3 characters long"), email: z.string().email("Invalid email address"), age: z.number().min(18).optional(), });

app.post( '/users', guard.validate({ body: createUserSchema }), // Validate request body (req, res) => { res.json({ success: true,WSA message: "User created successfully", data: req.body }); } );

Error Handler:

// This middleware must be registered after all routes app.use(guard.errorHandler());