public TransactionHashInfo Post([FromBody] TransactionModel request)
        {
            if (!ShouldSendCoins(request.RecipientAddress))
            {
                return(new TransactionHashInfo()
                {
                    IsValid = false,
                    ErrorMessage = "User has received coins in the last hour."
                });
            }

            if (request.Value > _appSettings.MaxAddressDonationPerHour)
            {
                return(new TransactionHashInfo()
                {
                    IsValid = false,
                    ErrorMessage = String.Format("User cannot receive more than {0} coins per hour.", _appSettings.MaxAddressDonationPerHour)
                });
            }

            var             privateKey = CryptoUtils.HexToByteArray(_appSettings.PrivateKey);
            var             publicKey  = CryptoUtils.GetPublicFor(privateKey);
            var             date       = DateTime.UtcNow;
            TransactionData dataToSign = GetDataToSign(request, publicKey, date);

            var json          = Newtonsoft.Json.JsonConvert.SerializeObject(dataToSign);
            var msgHash       = CryptoUtils.GetSha256Bytes(json);
            var signedMessage = CryptoUtils.BouncyCastleSign(msgHash, privateKey);

            // send http request to node
            var signedTransactionData = new TransactionDataSigned
            {
                From            = _appSettings.FaucetAddress,
                To              = request.RecipientAddress,
                Value           = request.Value,
                Fee             = 0,
                SenderPubKey    = CryptoUtils.ByteArrayToHex(publicKey),
                DateCreated     = date,
                SenderSignature = CryptoUtils.ByteArrayToHex(signedMessage)
            };

            var res = HttpUtils.DoApiPost <TransactionDataSigned, TransactionHashInfo>(request.NodeUrl, "api/transactions", signedTransactionData);

            if (res.IsValid)
            {
                // add transaction record with limits
                var recordHistory = new TransactionHistory
                {
                    Address      = request.RecipientAddress,
                    DateReceived = res.DateReceived,
                    Amount       = request.Value
                };
                _dbService.Add(request.RecipientAddress, recordHistory);
            }
            return(res);
        }