gistfile1.cs

public class User
    {
        public int Id { get; set; }
        public string Email { get; set; }
        public string FirstName { get; set; }
        public string first_name { get; set; }
        public string First_name { get; set; }
        public string First_Name { get; set; }
    }
    
    public List<User> Users()
        {
            var client = new RestClient(HarvestApiUrl);
            client.Authenticator = new HttpBasicAuthenticator(HarvestUserName, HarvestPassword);
            client.UserAgent = "spektrummedia";

            var request = new RestRequest("people")
            {
                Method = Method.GET,
                //Credentials = new NetworkCredential(HarvestUserName, HarvestPassword),
                RequestFormat = DataFormat.Json,
            };
            /*request.AddUrlSegment("user_id", "298203");
            request.AddParameter("from", "20140112");
            request.AddParameter("to", "20140119");*/

            var response = client.Execute<List<User>>(request);

            if (response.StatusCode != HttpStatusCode.OK &&
                response.StatusCode != HttpStatusCode.Created)
            {
                throw new Exception(response.ErrorMessage, response.ErrorException);
            }

            return response.Data;
        }
        
        

gistfile2.json

[{"user":
{"cost_rate":null,
"created_at":"2012-01-17T02:35:33Z",
"default_expense_category_id":null,
"default_expense_project_id":null,
"default_hourly_rate":70.0,
"default_task_id":null,
"default_time_project_id":null,
"department":"Dev",
"email":"aleclair@spektrummedia.com",
"first_name":"Antoine",
"has_access_to_all_future_projects":true,
"id":298202,
"identity_url":null,
"is_active":true,
"is_admin":false,
"is_contractor":false,
"last_name":"Leclair",
"opensocial_identifier":null,
"telephone":"",
"timezone":"Eastern Time (US & Canada)",
"updated_at":"2013-12-23T17:32:41Z",
"wants_newsletter":false,
"wants_weekly_digest":true,
"weekly_digest_sent_on":null}
},
{"user":{"cost_rate":null,"created_at":"2012-01-17T02:35:21Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":70.0,"default_task_id":null,"default_time_project_id":null,"department":"","email":"atheriault@spektrummedia.com","first_name":"Antoine","has_access_to_all_future_projects":true,"id":298201,"identity_url":null,"is_active":false,"is_admin":false,"is_contractor":false,"last_name":"Theriault","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2012-02-03T23:11:39Z","wants_newsletter":false,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2012-01-17T02:35:48Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":70.0,"default_task_id":null,"default_time_project_id":null,"department":"Dev","email":"couellet@spektrummedia.com","first_name":"Charles","has_access_to_all_future_projects":true,"id":298203,"identity_url":null,"is_active":true,"is_admin":false,"is_contractor":false,"last_name":"Ouellet","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-16T22:51:39Z","wants_newsletter":false,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2012-01-06T23:02:32Z","default_expense_category_id":801312,"default_expense_project_id":1881749,"default_hourly_rate":70.0,"default_task_id":1186144,"default_time_project_id":1881749,"department":"Gestion","email":"gsaad@spektrummedia.com","first_name":"Georges","has_access_to_all_future_projects":true,"id":293591,"identity_url":null,"is_active":true,"is_admin":true,"is_contractor":false,"last_name":"Saad","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-16T22:51:39Z","wants_newsletter":true,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2013-04-26T19:50:43Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":80.0,"default_task_id":null,"default_time_project_id":null,"department":"Dev","email":"gcoguiec@spektrummedia.com","first_name":"Guillaume","has_access_to_all_future_projects":true,"id":506760,"identity_url":null,"is_active":true,"is_admin":false,"is_contractor":false,"last_name":"Coguiec","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-16T22:51:39Z","wants_newsletter":true,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2013-01-21T13:56:14Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":null,"default_task_id":null,"default_time_project_id":null,"department":"Dev","email":"jdgauvin@spektrummedia.com","first_name":"Jean-Daniel","has_access_to_all_future_projects":true,"id":452802,"identity_url":null,"is_active":true,"is_admin":false,"is_contractor":false,"last_name":"Gauvin","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-17T16:37:03Z","wants_newsletter":true,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2012-01-06T22:49:34Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":70.0,"default_task_id":null,"default_time_project_id":null,"department":"Design","email":"jsimard@spektrummedia.com","first_name":"Jonathan","has_access_to_all_future_projects":true,"id":293583,"identity_url":null,"is_active":true,"is_admin":true,"is_contractor":false,"last_name":"Simard","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-16T22:51:39Z","wants_newsletter":true,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2012-01-17T02:35:06Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":70.0,"default_task_id":null,"default_time_project_id":null,"department":"Int\u00e9gration","email":"mebacher@spektrummedia.com","first_name":"Mathieu","has_access_to_all_future_projects":true,"id":298200,"identity_url":null,"is_active":true,"is_admin":true,"is_contractor":false,"last_name":"Ebacher","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-17T16:14:25Z","wants_newsletter":false,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2012-03-23T20:57:05Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":80.0,"default_task_id":null,"default_time_project_id":null,"department":"Int\u00e9gration","email":"sroy@spektrummedia.com","first_name":"Stephanie","has_access_to_all_future_projects":true,"id":326079,"identity_url":null,"is_active":true,"is_admin":false,"is_contractor":false,"last_name":"Roy","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-17T21:55:25Z","wants_newsletter":false,"wants_weekly_digest":true,"weekly_digest_sent_on":null}},{"user":{"cost_rate":null,"created_at":"2012-01-17T02:36:01Z","default_expense_category_id":null,"default_expense_project_id":null,"default_hourly_rate":70.0,"default_task_id":null,"default_time_project_id":null,"department":"Dev","email":"vgirard@spektrummedia.com","first_name":"Vincent","has_access_to_all_future_projects":true,"id":298204,"identity_url":null,"is_active":true,"is_admin":true,"is_contractor":false,"last_name":"Girard","opensocial_identifier":null,"telephone":"","timezone":"Eastern Time (US & Canada)","updated_at":"2014-01-18T14:05:47Z","wants_newsletter":false,"wants_weekly_digest":true,"weekly_digest_sent_on":null}}]