`@Injectable()`

Marks a class as a provider that can be managed and injected by the Nest IoC container.

Since NestJS 10/11 Spec ↗

Syntax

@Injectable(options?: InjectableOptions)

Parameters

Name	Type	Required	Description
`options`	`InjectableOptions`	No	Optional object with a scope (DEFAULT, REQUEST, or TRANSIENT) and durable flag.

Returns

ClassDecorator — A decorator applied to the provider class.

Examples

import { Injectable } from '@nestjs/common';

@Injectable()
export class CatsService {
  private cats: string[] = [];

  create(name: string) {
    this.cats.push(name);
  }

  findAll() {
    return this.cats;
  }
}

import { Injectable, Scope } from '@nestjs/common';

@Injectable({ scope: Scope.REQUEST })
export class RequestScopedService {}

Notes

@Injectable() enables a class to be resolved via dependency injection. Without it, constructor parameter metadata is not emitted and Nest cannot instantiate the provider. The default scope is singleton; use REQUEST or TRANSIENT scopes only when state must not be shared.