Validation (Zod)
Nova uses Zod for both request body validation and response validation. Validation errors are automatically returned as structured error responses.
Request Body Validation
Use the @Body decorator with a Zod schema to validate incoming request bodies:
dto/create-user.ts TypeScript
import { z } from 'zod';
export const CreateUserSchema = z.object({
name: z.string().min(2, 'Name must be at least 2 characters'),
email: z.string().email('Invalid email address'),
age: z.number().int().min(0).optional(),
role: z.enum(['admin', 'user', 'moderator']).default('user'),
});
export type CreateUserDto = z.infer<typeof CreateUserSchema>; user.controller.ts TypeScript
import { Controller, Post, Body } from '@abrahambass/nova';
import { CreateUserSchema, type CreateUserDto } from './dto/create-user';
@Controller('/users')
class UserController {
@Post()
async create(@Body(CreateUserSchema) data: CreateUserDto) {
// data is fully validated and typed
return { id: 1, ...data };
}
}Validation Error Response
When validation fails, Nova returns a structured error response:
Response (404) json
{
"detail": [
{
"loc": ["body", "email"],
"msg": "Invalid email address",
"type": "invalid"
},
{
"loc": ["body", "name"],
"msg": "Name must be at least 2 characters",
"type": "invalid"
}
]
}Response Validation
You can also validate the response using the responseModel option in your route decorator:
Example TypeScript
const UserResponseSchema = z.object({
id: z.number(),
name: z.string(),
email: z.string(),
});
@Get('/:id', {
responseModel: UserResponseSchema,
includeInSchema: true,
})
async findById(@Path('id') id: number) {
// If the return value doesn't match the schema,
// a ResponseValidationError (500) is thrown
return this.userService.findById(id);
}💡 Tip
Response validation is great for catching bugs in development. If the response doesn't match the schema, a 500 Internal Server Error is thrown so you can catch data shape issues early.
Path & Query Parameter Validation
Path and query parameters are automatically type-cast based on their TypeScript types:
| TypeScript Type | Casting Behavior | Error on Invalid |
|---|---|---|
string | Converted to string | No |
number | Parsed as number | Yes — InvalidParamTypeError |
boolean | Accepts "true"/"false" | Yes — InvalidParamTypeError |
Date | Parsed as Date | Yes — InvalidParamTypeError |