Validation

Bueno's validation module implements the Standard Schema interface, letting you use any compatible validation library — Zod, Valibot, ArkType, Typia, and more — with the same API.

Basic validation

import { validate } from '@buenojs/bueno/validation';
import { z } from 'zod';

const schema = z.object({
  name: z.string().min(1),
  email: z.string().email(),
  age: z.number().min(0).max(150),
});

const result = await validate(schema, data);

if (result.success) {
  console.log(result.data);  // typed as { name: string; email: string; age: number }
} else {
  console.log(result.issues);  // validation errors
}

Request validation helpers

Validate specific parts of the incoming request:

import {
  validateBody,
  validateQuery,
  validateParams,
  validateHeaders,
} from '@buenojs/bueno/validation';

app.post('/users', async (ctx) => {
  const body = await validateBody(ctx, z.object({
    name: z.string(),
    email: z.string().email(),
  }));

  if (!body.success) {
    return ctx.json({ errors: body.issues }, 422);
  }

  // body.data is fully typed
  return ctx.json({ user: body.data });
});

validateQuery

app.get('/search', async (ctx) => {
  const query = await validateQuery(ctx, z.object({
    q: z.string().optional(),
    page: z.coerce.number().default(1),
    limit: z.coerce.number().max(100).default(20),
  }));

  if (!query.success) {
    return ctx.json({ errors: query.issues }, 400);
  }

  const { q, page, limit } = query.data;
  // ...
});

validateParams

app.get('/users/:id', async (ctx) => {
  const params = await validateParams(ctx, z.object({
    id: z.coerce.number().positive(),
  }));

  if (!params.success) {
    return ctx.notFound();
  }

  const userId = params.data.id;  // number
});

Supported libraries

Any library implementing Standard Schema:

Library	Version	Notes
Zod	4+	Most popular, excellent DX
Valibot	v1+	Smallest bundle size
ArkType	Latest	Fastest validation speed
Typia	7+	Compile-time validation

Inline validation

For quick checks without importing a full schema library:

import { validate } from '@buenojs/bueno/validation';

// Works with any Standard Schema-compliant object
const result = await validate(mySchema, data);

Error format

Validation errors follow the Standard Schema issue format:

interface ValidationIssue {
  message: string;
  path?: (string | number | symbol)[];
}

Integration with modules

When using the DI module system, validation can be applied at the controller level:

@Post('/users')
@UseGuards(ValidationGuard(CreateUserDto))
async createUser(@Body() body: CreateUserDto) {
  return this.userService.create(body);
}