using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var data = Newtonsoft.Json.JsonConvert.DeserializeObject<RecordCollection>(JSON);

        string key = data.Records.First().S3.Object.Key;

        FiddleHelper.Dump(key);

    }

    public static string JSON = @"{

    ""Records"": [

        {

            ""eventVersion"": ""2.1"",

            ""eventSource"": ""aws:s3"",

            ""awsRegion"": ""us-east-1"",

            ""eventTime"": ""2023-12-05T17:23:02.224Z"",

            ""eventName"": ""ObjectCreated:Put"",

            ""userIdentity"": {

                ""principalId"": ""AWS:AROAS5H3QG7KOVIL3BB2:AKhan@acme.com""

            },

            ""requestParameters"": {

                ""sourceIPAddress"": ""165.225.37.34""

            },

            ""responseElements"": {

                ""x-amz-request-id"": ""FRWTRYC074JJJNQ"",

                ""x-amz-id-2"": ""FeHspqXTy4RoPNzWRqoz6bx9oBGODiKnBjHdf/RgnahoWVQ2c/wO/qnb84oNfiiftMCBOoZGsGvYMNQ+z/gFV47dZEW3eHtYKZYU+uB45Ao""

            },

            ""s3"": {

                ""s3SchemaVersion"": ""1.0"",

                ""configurationId"": ""AS400Sqs"",

                ""bucket"": {

                    ""name"": ""oola-as400"",

                    ""ownerIdentity"": {

                        ""principalId"": ""A2Y4V7DQVMOJS""

                    },

                    ""arn"": ""arn:aws:s3:::oola-as400""

                },

                ""object"": {

                    ""key"": ""C0067391_test1_new.xml"",

                    ""size"": 2974,

                    ""eTag"": ""c6715fc835acab3281f93c42e66c3f5"",

                    ""sequencer"": ""00656F5C762884679""

                }

            }

        }

    ]

}

";

}

public class RecordCollection 

{

    public List<EventRecord> Records { get;set; }

}

public class EventRecord

{

    public string EventVersion { get;set; }

    // ...

    public S3 S3 { get;set; }

}

public class S3 

{

    public string S3SchemaVersion { get;set; }

    public string ConfigurationId { get;set; }

    public Entry Object { get;set; }

}

public class Entry 

{

    public string Key { get;set; }

    public string Size { get;set; }

    public string ETag { get;set; }

    public string Sequencer { get;set; }

}

​