Не документированное API Rapira.net курс USDT\RUB

ApiRapia.cs

public class ApiRapira
{
    static string apiurl = "https://api.rapira.net/market/symbol-thumb";

    public static async Task<double> GetCurrentRateFiat()
    {
        var currentRub = await CustomHttpPostResponseAsync();
        if (currentRub == 0)
        {
            return await ApiBybit.GetCurrentRateFiat();
        }
        
        return currentRub;
    }

    private static async Task<double> CustomHttpPostResponseAsync()
    {
        using (var client = new HttpClient())
        {
            // Добавляем заголовки
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
            client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("gzip"));
            client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("deflate"));
            client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("br"));
            client.DefaultRequestHeaders.AcceptEncoding.Add(new StringWithQualityHeaderValue("zstd"));
            client.DefaultRequestHeaders.AcceptLanguage.Add(new StringWithQualityHeaderValue("en"));
            client.DefaultRequestHeaders.Add("dnt", "1");
            client.DefaultRequestHeaders.Add("origin", "https://rapira.net");

            var response = await client.PostAsync(apiurl, null);

            if (response.IsSuccessStatusCode)
            {
                var responseStream = await response.Content.ReadAsStreamAsync();
                string responseContent;

                // Проверяем, сжат ли ответ
                if (response.Content.Headers.ContentEncoding.Contains("gzip"))
                {
                    using (var decompressedStream = new GZipStream(responseStream, CompressionMode.Decompress))
                    using (var reader = new StreamReader(decompressedStream))
                    {
                        responseContent = await reader.ReadToEndAsync();
                    }
                }
                else if (response.Content.Headers.ContentEncoding.Contains("deflate"))
                {
                    using (var decompressedStream = new DeflateStream(responseStream, CompressionMode.Decompress))
                    using (var reader = new StreamReader(decompressedStream))
                    {
                        responseContent = await reader.ReadToEndAsync();
                    }
                }
                else
                {
                    using (var reader = new StreamReader(responseStream))
                    {
                        responseContent = await reader.ReadToEndAsync();
                    }
                }


                // Парсим как массив
                JArray dataArray = JArray.Parse(responseContent);

                var usdtRubItem = dataArray.FirstOrDefault(x => x["symbol"]?.ToString() == "USDT/RUB");
                if (usdtRubItem != null)
                {
                    string price = usdtRubItem["close"]?.ToString();
                    if (double.TryParse(price, out double _price))
                    {
                        return _price;
                    }
                    else
                    {
                        return 0;
                    }

                }
            }
        }

        return 0;
    }
}