Request Validation

Easy — everyone uses thisBackend

ELI5 — The Vibe Check

Request validation is checking that incoming data makes sense before you do anything with it. Is the email actually an email? Is the age a number and not 'banana'? It's like checking IDs at the door — reject the nonsense before it gets inside.

Real Talk

Request validation verifies that incoming HTTP request data (body, query params, path params, headers) conforms to expected schemas and constraints. It catches malformed data early, prevents injection attacks, and provides clear error messages. Libraries like Joi, Zod, Pydantic, and class-validator automate schema-based validation.

Show Me The Code

import { z } from 'zod';

const CreateUserSchema = z.object({
  email: z.string().email(),
  age: z.number().min(13).max(120),
  name: z.string().min(1).max(100)
});

const data = CreateUserSchema.parse(req.body); // throws if invalid

When You'll Hear This

"Always validate request data — never trust the client." / "Zod catches the invalid email before it reaches the database."

Related Terms

Input Validation

Input validation is checking that user input is what you expect before using it.

beginnerSecurity

Pydantic

Pydantic is Python's strict bouncer at the data nightclub.

intermediateBackend

Validation

Validation is your backend's bouncer. Before any data gets into the database, the bouncer checks it: 'Is this email actually an email?

beginnerBackend

Zod

Zod is your runtime bouncer for TypeScript. TypeScript checks types at build time, but Zod checks them when actual data arrives. API response looks weird?

intermediateFrontend

Back to Browse Random Term