1. Install Required Packages

You need Newtonsoft.Json for logging structured data and System.Net.Http for API requests. Install via NuGet:

dotnet add package Newtonsoft.Json

2. Write the C# Monitoring Script

This script sends API requests, checks responses, logs performance, and reports issues.

using System;
using System.Diagnostics;
using System.Net.Http;
using System.Threading.Tasks;
using Newtonsoft.Json;

class Program
{
    static async Task Main()
    {
        string apiUrl = "https://your-api-url.com/health"; // Replace with your API endpoint
        using HttpClient client = new HttpClient();

        try
        {
            Stopwatch stopwatch = Stopwatch.StartNew();
            HttpResponseMessage response = await client.GetAsync(apiUrl);
            stopwatch.Stop();

            var logEntry = new
            {
                Timestamp = DateTime.UtcNow,
                ApiUrl = apiUrl,
                StatusCode = (int)response.StatusCode,
                ResponseTimeMs = stopwatch.ElapsedMilliseconds,
                Success = response.IsSuccessStatusCode
            };

            Console.WriteLine(JsonConvert.SerializeObject(logEntry, Formatting.Indented));

            if (!response.IsSuccessStatusCode)
            {
                ReportToNewRelic(logEntry);
            }
        }
        catch (Exception ex)
        {
            var errorLog = new
            {
                Timestamp = DateTime.UtcNow,
                ApiUrl = apiUrl,
                Error = ex.Message,
                Success = false
            };

            Console.WriteLine(JsonConvert.SerializeObject(errorLog, Formatting.Indented));
            ReportToNewRelic(errorLog);
        }
    }

    static void ReportToNewRelic(object logData)
    {
        // Placeholder for sending logs to New Relic
        Console.WriteLine("Reporting issue to New Relic...");
        // You can integrate with New Relic's API or log monitoring system
    }
}

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3. How It Works

✅ Sends API requests to the health check endpoint.
✅ Measures response time in milliseconds.
✅ Logs API status, response code, and errors.
✅ Reports failures to New Relic (custom integration needed).

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4. Automating API Monitoring

To run this script automatically:

1. Use Windows Task Scheduler (Windows) or a Cron Job (Linux/Mac)
2. Run every 5 minutes to check API health
3. Extend logging to New Relic by sending data to New Relic Logs API

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5. Sending Data to New Relic Logs API

To log issues in New Relic, send API data using HttpClient:

static async void ReportToNewRelic(object logData)
{
    string newRelicApiKey = "YOUR_NEW_RELIC_LICENSE_KEY";
    string newRelicLogEndpoint = "https://log-api.newrelic.com/log/v1";

    using HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Add("Api-Key", newRelicApiKey);
    client.DefaultRequestHeaders.Add("Content-Type", "application/json");

    string jsonPayload = JsonConvert.SerializeObject(new { logs = new[] { logData } });

    try
    {
        HttpResponseMessage response = await client.PostAsync(newRelicLogEndpoint, new StringContent(jsonPayload));
        Console.WriteLine($"New Relic Log Response: {response.StatusCode}");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Failed to send logs to New Relic: {ex.Message}");
    }
}