# Hello Amazon Cognito
Hello Amazon Cognito

The following code examples show how to get started using Amazon Cognito.

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/cognito/hello_cognito#code-examples). 
Code for the CMakeLists.txt CMake file.  

```
# Set the minimum required version of CMake for this project.
cmake_minimum_required(VERSION 3.13)

# Set the AWS service components used by this project.
set(SERVICE_COMPONENTS cognito-idp)

# Set this project's name.
project("hello_cognito")

# Set the C++ standard to use to build this target.
# At least C++ 11 is required for the AWS SDK for C++.
set(CMAKE_CXX_STANDARD 11)

# Use the MSVC variable to determine if this is a Windows build.
set(WINDOWS_BUILD ${MSVC})

if (WINDOWS_BUILD) # Set the location where CMake can find the installed libraries for the AWS SDK.
    string(REPLACE ";" "/aws-cpp-sdk-all;" SYSTEM_MODULE_PATH "${CMAKE_SYSTEM_PREFIX_PATH}/aws-cpp-sdk-all")
    list(APPEND CMAKE_PREFIX_PATH ${SYSTEM_MODULE_PATH})
endif ()

# Find the AWS SDK for C++ package.
find_package(AWSSDK REQUIRED COMPONENTS ${SERVICE_COMPONENTS})

if (WINDOWS_BUILD AND AWSSDK_INSTALL_AS_SHARED_LIBS)
     # Copy relevant AWS SDK for C++ libraries into the current binary directory for running and debugging.

     # set(BIN_SUB_DIR "/Debug") # If you are building from the command line, you may need to uncomment this 
                                    # and set the proper subdirectory to the executables' location.

     AWSSDK_CPY_DYN_LIBS(SERVICE_COMPONENTS "" ${CMAKE_CURRENT_BINARY_DIR}${BIN_SUB_DIR})
endif ()

add_executable(${PROJECT_NAME}
        hello_cognito.cpp)

target_link_libraries(${PROJECT_NAME}
        ${AWSSDK_LINK_LIBRARIES})
```
Code for the hello\$1cognito.cpp source file.  

```
#include <aws/core/Aws.h>
#include <aws/cognito-idp/CognitoIdentityProviderClient.h>
#include <aws/cognito-idp/model/ListUserPoolsRequest.h>
#include <iostream>

/*
 *  A "Hello Cognito" starter application which initializes an Amazon Cognito client and lists the Amazon Cognito
 *  user pools.
 *
 *  main function
 *
 *  Usage: 'hello_cognito'
 *
 */

int main(int argc, char **argv) {
    Aws::SDKOptions options;
    // Optionally change the log level for debugging.
//   options.loggingOptions.logLevel = Utils::Logging::LogLevel::Debug;
    Aws::InitAPI(options); // Should only be called once.
    int result = 0;
    {
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region (overrides config file).
        // clientConfig.region = "us-east-1";

        Aws::CognitoIdentityProvider::CognitoIdentityProviderClient cognitoClient(clientConfig);

        Aws::String nextToken; // Used for pagination.
        std::vector<Aws::String> userPools;

        do {
            Aws::CognitoIdentityProvider::Model::ListUserPoolsRequest listUserPoolsRequest;
            if (!nextToken.empty()) {
                listUserPoolsRequest.SetNextToken(nextToken);
            }

            Aws::CognitoIdentityProvider::Model::ListUserPoolsOutcome listUserPoolsOutcome =
                    cognitoClient.ListUserPools(listUserPoolsRequest);

            if (listUserPoolsOutcome.IsSuccess()) {
                for (auto &userPool: listUserPoolsOutcome.GetResult().GetUserPools()) {

                    userPools.push_back(userPool.GetName());
                }

                nextToken = listUserPoolsOutcome.GetResult().GetNextToken();
            } else {
                std::cerr << "ListUserPools error: " << listUserPoolsOutcome.GetError().GetMessage() << std::endl;
                result = 1;
                break;
            }


        } while (!nextToken.empty());
        std::cout << userPools.size() << " user pools found." << std::endl;
        for (auto &userPool: userPools) {
            std::cout << "   user pool: " << userPool << std::endl;
        }
    }

    Aws::ShutdownAPI(options); // Should only be called once.
    return result;
}
```
+  For API details, see [ListUserPools](https://docs.aws.amazon.com/goto/SdkForCpp/cognito-idp-2016-04-18/ListUserPools) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/cognito#code-examples). 

```
package main

import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
)

// main uses the AWS SDK for Go V2 to create an Amazon Simple Notification Service
// (Amazon SNS) client and list the topics in your account.
// This example uses the default settings specified in your shared credentials
// and config files.
func main() {
	ctx := context.Background()
	sdkConfig, err := config.LoadDefaultConfig(ctx)
	if err != nil {
		fmt.Println("Couldn't load default configuration. Have you set up your AWS account?")
		fmt.Println(err)
		return
	}
	cognitoClient := cognitoidentityprovider.NewFromConfig(sdkConfig)
	fmt.Println("Let's list the user pools for your account.")
	var pools []types.UserPoolDescriptionType
	paginator := cognitoidentityprovider.NewListUserPoolsPaginator(
		cognitoClient, &cognitoidentityprovider.ListUserPoolsInput{MaxResults: aws.Int32(10)})
	for paginator.HasMorePages() {
		output, err := paginator.NextPage(ctx)
		if err != nil {
			log.Printf("Couldn't get user pools. Here's why: %v\n", err)
		} else {
			pools = append(pools, output.UserPools...)
		}
	}
	if len(pools) == 0 {
		fmt.Println("You don't have any user pools!")
	} else {
		for _, pool := range pools {
			fmt.Printf("\t%v: %v\n", *pool.Name, *pool.Id)
		}
	}
}
```
+  For API details, see [ListUserPools](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.ListUserPools) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/cognito#code-examples). 

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cognitoidentityprovider.CognitoIdentityProviderClient;
import software.amazon.awssdk.services.cognitoidentityprovider.model.CognitoIdentityProviderException;
import software.amazon.awssdk.services.cognitoidentityprovider.model.ListUserPoolsResponse;
import software.amazon.awssdk.services.cognitoidentityprovider.model.ListUserPoolsRequest;

/**
 * Before running this Java V2 code example, set up your development
 * environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class ListUserPools {
    public static void main(String[] args) {
        CognitoIdentityProviderClient cognitoClient = CognitoIdentityProviderClient.builder()
                .region(Region.US_EAST_1)
                .build();

        listAllUserPools(cognitoClient);
        cognitoClient.close();
    }

    public static void listAllUserPools(CognitoIdentityProviderClient cognitoClient) {
        try {
            ListUserPoolsRequest request = ListUserPoolsRequest.builder()
                    .maxResults(10)
                    .build();

            ListUserPoolsResponse response = cognitoClient.listUserPools(request);
            response.userPools().forEach(userpool -> {
                System.out.println("User pool " + userpool.name() + ", User ID " + userpool.id());
            });

        } catch (CognitoIdentityProviderException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }
}
```
+  For API details, see [ListUserPools](https://docs.aws.amazon.com/goto/SdkForJavaV2/cognito-idp-2016-04-18/ListUserPools) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cognito-identity-provider#code-examples). 

```
import {
  paginateListUserPools,
  CognitoIdentityProviderClient,
} from "@aws-sdk/client-cognito-identity-provider";

const client = new CognitoIdentityProviderClient({});

export const helloCognito = async () => {
  const paginator = paginateListUserPools({ client }, {});

  const userPoolNames = [];

  for await (const page of paginator) {
    const names = page.UserPools.map((pool) => pool.Name);
    userPoolNames.push(...names);
  }

  console.log("User pool names: ");
  console.log(userPoolNames.join("\n"));
  return userPoolNames;
};
```
+  For API details, see [ListUserPools](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/cognito-identity-provider/command/ListUserPoolsCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/cognito#code-examples). 

```
import boto3

# Create a Cognito Identity Provider client
cognitoidp = boto3.client("cognito-idp")

# Initialize a paginator for the list_user_pools operation
paginator = cognitoidp.get_paginator("list_user_pools")

# Create a PageIterator from the paginator
page_iterator = paginator.paginate(MaxResults=10)

# Initialize variables for pagination
user_pools = []

# Handle pagination
for page in page_iterator:
    user_pools.extend(page.get("UserPools", []))

# Print the list of user pools
print("User Pools for the account:")
if user_pools:
    for pool in user_pools:
        print(f"Name: {pool['Name']}, ID: {pool['Id']}")
else:
    print("No user pools found.")
```
+  For API details, see [ListUserPools](https://docs.aws.amazon.com/goto/boto3/cognito-idp-2016-04-18/ListUserPools) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/cognito#code-examples). 

```
require 'aws-sdk-cognitoidentityprovider'
require 'logger'

# CognitoManager is a class responsible for managing AWS Cognito operations
# such as listing all user pools in the current AWS account.
class CognitoManager
  def initialize(client)
    @client = client
    @logger = Logger.new($stdout)
  end

  # Lists and prints all user pools associated with the AWS account.
  def list_user_pools
    paginator = @client.list_user_pools(max_results: 10)
    user_pools = []
    paginator.each_page do |page|
      user_pools.concat(page.user_pools)
    end

    if user_pools.empty?
      @logger.info('No Cognito user pools found.')
    else
      user_pools.each do |user_pool|
        @logger.info("User pool ID: #{user_pool.id}")
        @logger.info("User pool name: #{user_pool.name}")
        @logger.info("User pool status: #{user_pool.status}")
        @logger.info('---')
      end
    end
  end
end

if $PROGRAM_NAME == __FILE__
  cognito_client = Aws::CognitoIdentityProvider::Client.new
  manager = CognitoManager.new(cognito_client)
  manager.list_user_pools
end
```
+  For API details, see [ListUserPools](https://docs.aws.amazon.com/goto/SdkForRubyV3/cognito-idp-2016-04-18/ListUserPools) in *AWS SDK for Ruby API Reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using this service with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.