Integration Guide

The @nestjs-cognito/core package provides two main adapters for AWS Cognito integration:

CognitoJwtVerifier: An adapter for verifying JWT tokens issued by AWS Cognito
CognitoIdentityProvider: An adapter for interacting with AWS Cognito user management services

This guide demonstrates how to effectively use these adapters in your NestJS applications.

Common Integration Patterns

Using JWT Verification

import { CognitoJwtVerifier, InjectCognitoJwtVerifier } from '@nestjs-cognito/core';

@Injectable()
export class AuthService {
  constructor(
    @InjectCognitoJwtVerifier()
    private readonly jwtVerifier: CognitoJwtVerifier
  ) {}

  async validateToken(token: string) {
    return this.jwtVerifier.verify(token);
  }
}

Using Identity Provider

import { CognitoIdentityProvider } from '@aws-sdk/client-cognito-identity-provider';
import { InjectCognitoIdentityProvider } from '@nestjs-cognito/core';

@Injectable()
export class UserService {
  constructor(
    @InjectCognitoIdentityProvider()
    private readonly cognitoClient: CognitoIdentityProvider
  ) {}

  async getUser(username: string) {
    return this.cognitoClient.adminGetUser({
      UserPoolId: 'your-user-pool-id',
      Username: username
    });
  }
}

Module Integration Examples

Using with @nestjs-cognito/auth Package

When implementing authentication features using the auth package, use CognitoAuthModule:

import { CognitoAuthModule } from '@nestjs-cognito/auth';

@Module({
  imports: [
    CognitoAuthModule.register({
      identityProvider: {
        region: process.env.AWS_REGION,
        credentials: {
          accessKeyId: process.env.AWS_ACCESS_KEY_ID,
          secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
        },
      },
      jwtVerifier: {
        userPoolId: process.env.COGNITO_USER_POOL_ID,
        clientId: process.env.COGNITO_CLIENT_ID,
        tokenUse: 'access',
      },
    }),
  ],
})
export class AppModule {}

Using Core Package Only

When you only need core functionality without authentication features, use CognitoModule:

import { CognitoModule } from '@nestjs-cognito/core';

@Module({
  imports: [
    CognitoModule.register({
      identityProvider: {
        region: process.env.AWS_REGION,
        credentials: {
          accessKeyId: process.env.AWS_ACCESS_KEY_ID,
          secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
        },
      },
      jwtVerifier: {
        userPoolId: process.env.COGNITO_USER_POOL_ID,
        clientId: process.env.COGNITO_CLIENT_ID,
        tokenUse: 'access',
      },
    }),
  ],
})
export class AppModule {}

Choose the appropriate module based on your implementation needs:

Use CognitoAuthModule when you need authentication features from the @nestjs-cognito/auth package
Use CognitoModule when you only need core functionality like JWT verification and Cognito Identity Provider integration