Leveraging CoinGecko API with Azure Functions for Serverless Crypto Solutions

Function.cs

using System;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;
using System.Net;
using System.Net.Mail;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Collections.Generic;


namespace CoinGecko.CryptoAlerts
{
    public static class CheckCryptoPrices
    {
        private static readonly HttpClient client = new HttpClient();


        [FunctionName("CheckCryptoPrices")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");


            string apiKey = Environment.GetEnvironmentVariable("COINGECKO_API_KEY");
            string gmailPassword = Environment.GetEnvironmentVariable("GMAIL_PASSWORD");
            string alertEmail = Environment.GetEnvironmentVariable("ALERT_EMAIL");


            string responseString = await client.GetStringAsync($"https://api.coingecko.com/api/v3/simple/price?ids=bitcoin,ethereum&vs_currencies=usd&x_cg_pro_api_key={apiKey}");


            var prices = JsonConvert.DeserializeObject<Dictionary<string, Dictionary<string, decimal>>>(responseString);


            decimal bitcoinPrice = prices["bitcoin"]["usd"];
            decimal ethereumPrice = prices["ethereum"]["usd"];


            if (bitcoinPrice < 30000)
            {
                // Send alert email
                var fromAddress = new MailAddress(alertEmail, "Crypto Alert");
                var toAddress = new MailAddress(alertEmail, "Crypto Alert Recipient");
                const string subject = "Bitcoin Price Alert";
                string body = $"Bitcoin price dropped below $30,000! Current price: ${bitcoinPrice}\nEthereum price: ${ethereumPrice}";


                var smtp = new SmtpClient
                {
                    Host = "smtp.gmail.com",
                    Port = 587,
                    EnableSsl = true,
                    DeliveryMethod = SmtpDeliveryMethod.Network,
                    UseDefaultCredentials = false,
                    Credentials = new NetworkCredential(fromAddress.Address, gmailPassword)
                };


                using (var message = new MailMessage(fromAddress, toAddress)
                {
                    Subject = subject,
                    Body = body
                })
                {
                    smtp.Send(message);
                }


                log.LogInformation("Bitcoin price dropped below $30,000! Email alert sent.");
            }


            return new OkObjectResult(prices);
        }
    }
}