Controllers
Controllers receive incoming requests and return responses to the client.
@Controller('prefix')A controller is responsible for handling incoming requests and sending back responses. Each controller maps to a group of related routes.
How it works
You mark a class with the @Controller() decorator and give it a route prefix. Methods inside become route handlers when decorated with an HTTP method decorator such as @Get().
Controllers should stay thin: their job is to receive input and return output, delegating real work to services.
Example
import { Controller, Get } from '@nestjs/common';
@Controller('cats')
export class CatsController {
@Get()
findAll(): string {
return 'This returns all cats';
}
}When to use it
- A developer creates a ProductsController to group all HTTP endpoints for the products resource under a single class.
- A team uses separate controllers (AuthController, UsersController, OrdersController) so each feature's routes are easy to find and test independently.
- A backend engineer decorates a controller with @UseGuards so every route inside it requires a valid JWT without repeating the guard on each method.
More examples
Minimal controller
Defines a controller that maps GET /cats to the findAll method — the simplest controller form.
import { Controller, Get } from '@nestjs/common';
@Controller('cats')
export class CatsController {
@Get()
findAll(): string {
return 'This returns all cats';
}
}Register controller in module
Shows that controllers must be declared in the controllers array of their owning module to be active.
import { Module } from '@nestjs/common';
import { CatsController } from './cats.controller';
@Module({
controllers: [CatsController],
})
export class CatsModule {}Controller with injected service
Demonstrates a realistic controller that delegates to a service and accepts a typed body DTO.
import { Controller, Get, Post, Body } from '@nestjs/common';
import { CatsService } from './cats.service';
import { CreateCatDto } from './dto/create-cat.dto';
@Controller('cats')
export class CatsController {
constructor(private readonly catsService: CatsService) {}
@Get()
findAll() { return this.catsService.findAll(); }
@Post()
create(@Body() dto: CreateCatDto) { return this.catsService.create(dto); }
}
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