List the subscribers of an Amazon SNS topic using an Amazon SDK

    using System;
    using System.Collections.Generic;
    using System.Threading.Tasks;
    using Amazon.SimpleNotificationService;
    using Amazon.SimpleNotificationService.Model;

    /// <summary>
    /// This example will retrieve a list of the existing Amazon Simple
    /// Notification Service (Amazon SNS) subscriptions. The example was
    /// created using the AWS SDK for .NET 3.7 and .NET Core 5.0.
    /// </summary>
    public class ListSubscriptions
    {
        public static async Task Main()
        {
            IAmazonSimpleNotificationService client = new AmazonSimpleNotificationServiceClient();

            var subscriptions = await GetSubscriptionsListAsync(client);

            DisplaySubscriptionList(subscriptions);
        }

        /// <summary>
        /// Gets a list of the existing Amazon SNS subscriptions.
        /// </summary>
        /// <param name="client">The initialized Amazon SNS client object used
        /// to obtain the list of subscriptions.</param>
        /// <returns>A List containing information about each subscription.</returns>
        public static async Task<List<Subscription>> GetSubscriptionsListAsync(IAmazonSimpleNotificationService client)
        {
            var response = await client.ListSubscriptionsAsync();

            return response.Subscriptions;
        }

        /// <summary>
        /// Display a list of Amazon SNS subscription information.
        /// </summary>
        /// <param name="subscriptionList">A list containing details for existing
        /// Amazon SNS subscriptions.</param>
        public static void DisplaySubscriptionList(List<Subscription> subscriptionList)
        {
            foreach (var subscription in subscriptionList)
            {
                Console.WriteLine($"Owner: {subscription.Owner}");
                Console.WriteLine($"Subscription ARN: {subscription.SubscriptionArn}");
                Console.WriteLine($"Topic ARN: {subscription.TopicArn}");
                Console.WriteLine($"Endpoint: {subscription.Endpoint}");
                Console.WriteLine($"Protocol: {subscription.Protocol}");
                Console.WriteLine();
            }
        }
    }

  Aws::SDKOptions options;
  Aws::InitAPI(options);
  {
    Aws::SNS::SNSClient sns;

    Aws::SNS::Model::ListSubscriptionsRequest ls_req;

    auto ls_out = sns.ListSubscriptions(ls_req);

    if (ls_out.IsSuccess())
    {
        std::cout << "Subscriptions list:" << std::endl;
        for (auto const& subscription : ls_out.GetResult().GetSubscriptions())
        {
            std::cout << "  * " << subscription.GetSubscriptionArn() << std::endl;
        }
    }
    else
    {
      std::cout << "Error listing subscriptions " << ls_out.GetError().GetMessage() <<
        std::endl;
    }
  }

  Aws::ShutdownAPI(options);

    public static void listSNSSubscriptions( SnsClient snsClient) {

        try {
            ListSubscriptionsRequest request = ListSubscriptionsRequest.builder()
                .build();

            ListSubscriptionsResponse result = snsClient.listSubscriptions(request);
            System.out.println(result.subscriptions());

        } catch (SnsException e) {

            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

Create the client in a separate module and export it.

import  { SNSClient } from "@aws-sdk/client-sns";
// Set the AWS Region.
const REGION = "REGION"; //e.g. "us-east-1"
// Create SNS service object.
const snsClient = new SNSClient({ region: REGION });
export  { snsClient };

Import the SDK and client modules and call the API.

// Import required AWS SDK clients and commands for Node.js
import {ListSubscriptionsByTopicCommand } from "@aws-sdk/client-sns";
import {snsClient } from "./libs/snsClient.js";

// Set the parameters
const params = { TopicArn: "TOPIC_ARN" }; //TOPIC_ARN

const run = async () => {
  try {
    const data = await snsClient.send(new ListSubscriptionsByTopicCommand(params));
    console.log("Success.",  data);
    return data; // For unit tests.
  } catch (err) {
    console.log("Error", err.stack);
  }
};
run();

suspend fun listSNSSubscriptions() {

    SnsClient { region = "us-east-1" }.use { snsClient ->
        val response = snsClient.listSubscriptions(ListSubscriptionsRequest {})
        response.subscriptions?.forEach { sub ->
            println("Sub ARN is ${sub.subscriptionArn}")
            println("Sub protocol is ${sub.protocol}")
        }
    }
}

require 'vendor/autoload.php';

use Aws\Sns\SnsClient; 
use Aws\Exception\AwsException;

/**
 * Returns a list of Amazon SNS subscriptions in the requested region.
 *
 * This code expects that you have AWS credentials set up per:
 * https://docs.aws.amazon.com/sdk-for-php/v3/developer-guide/guide_credentials.html
 */
 
$SnSclient = new SnsClient([
    'profile' => 'default',
    'region' => 'us-east-1',
    'version' => '2010-03-31'
]);

try {
    $result = $SnSclient->listSubscriptions([
    ]);
    var_dump($result);
} catch (AwsException $e) {
    // output error message if fails
    error_log($e->getMessage());
}
 

class SnsWrapper:
    """Encapsulates Amazon SNS topic and subscription functions."""
    def __init__(self, sns_resource):
        """
        :param sns_resource: A Boto3 Amazon SNS resource.
        """
        self.sns_resource = sns_resource

    def list_subscriptions(self, topic=None):
        """
        Lists subscriptions for the current account, optionally limited to a
        specific topic.

        :param topic: When specified, only subscriptions to this topic are returned.
        :return: An iterator that yields the subscriptions.
        """
        try:
            if topic is None:
                subs_iter = self.sns_resource.subscriptions.all()
            else:
                subs_iter = topic.subscriptions.all()
            logger.info("Got subscriptions.")
        except ClientError:
            logger.exception("Couldn't get subscriptions.")
            raise
        else:
            return subs_iter

require "aws-sdk-sns"  # v2: require 'aws-sdk'

def show_subscriptions?(sns_client, topic_arn)
  topic = sns_client.topic(topic_arn)
  topic.subscriptions.each do |s|
    puts s.attributes["Endpoint"]
  end

rescue StandardError => e
  puts "Error while sending the message: #{e.message}"
end

def run_me

  topic_arn = "SNS_TOPIC_ARN"
  region = "REGION"

  sns_client = Aws::SNS::Resource.new(region: region)

  puts "Listing subscriptions to the topic."

  if show_subscriptions?(sns_client, topic_arn)
  else
    puts "There was an error. Stopping program."
    exit 1
  end
end

run_me if $PROGRAM_NAME == __FILE__

    TRY.
        oo_result = lo_sns->listsubscriptions( ).                " oo_result is returned for testing purposes. "
        DATA(lt_subscriptions) = oo_result->get_subscriptions( ).
        MESSAGE 'Retrieved list of subscribers.' TYPE 'I'.
      CATCH /aws1/cx_rt_generic.
        MESSAGE 'Unable to list subscribers.' TYPE 'E'.
    ENDTRY.