Use ListStreamConsumers with an AWS SDK

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

    /// <summary>
    /// List the consumers of an Amazon Kinesis stream.
    /// </summary>
    public class ListConsumers
    {
        public static async Task Main()
        {
            IAmazonKinesis client = new AmazonKinesisClient();

            string streamARN = "arn:aws:kinesis:us-east-2:000000000000:stream/AmazonKinesisStream";
            int maxResults = 10;

            var consumers = await ListConsumersAsync(client, streamARN, maxResults);

            if (consumers.Count > 0)
            {
                consumers
                    .ForEach(c => Console.WriteLine($"Name: {c.ConsumerName} ARN: {c.ConsumerARN}"));
            }
            else
            {
                Console.WriteLine("No consumers found.");
            }
        }

        /// <summary>
        /// Retrieve a list of the consumers for a Kinesis stream.
        /// </summary>
        /// <param name="client">An initialized Kinesis client object.</param>
        /// <param name="streamARN">The ARN of the stream for which we want to
        /// retrieve a list of clients.</param>
        /// <param name="maxResults">The maximum number of results to return.</param>
        /// <returns>A list of Consumer objects.</returns>
        public static async Task<List<Consumer>> ListConsumersAsync(IAmazonKinesis client, string streamARN, int maxResults)
        {
            var request = new ListStreamConsumersRequest
            {
                StreamARN = streamARN,
                MaxResults = maxResults,
            };

            var response = await client.ListStreamConsumersAsync(request);

            return response.Consumers;
        }
    }