bool validateParams = ((params.size() == 4) && (params[3].get_str() == "validate"));
    //if validate mode enabled
    if(validateParams) {
        Object result;
        XBridgeTransactionDescrPtr ptr;
        {
            boost::mutex::scoped_lock l(XBridgeApp::m_txLocker);
            if (!XBridgeApp::m_pendingTransactions.count(id)) {
                statusCode = xbridge::TRANSACTION_NOT_FOUND;
                result.emplace_back(Pair("error",
                                        xbridge::xbridgeErrorText(statusCode, id.GetHex())));
                result.emplace_back(Pair("code", statusCode));
                return  result;
            }
            ptr = XBridgeApp::m_pendingTransactions[id];
        }

        // check sesssion
        XBridgeSessionPtr s = XBridgeApp::instance().sessionByCurrency(ptr->toCurrency);
        if (!s) {
            // no session
            statusCode = xbridge::NO_SESSION;
            result.emplace_back(Pair("error",
                                    xbridge::xbridgeErrorText(statusCode, ptr->toCurrency)));
            result.emplace_back(Pair("code", statusCode));
            return  result;
        }
        // check amount
        if (!s->checkAmount(ptr->toAmount)) {
            statusCode = xbridge::INSIFFICIENT_FUNDS;
            result.emplace_back(Pair("error",
                                     xbridge::xbridgeErrorText(statusCode, ptr->to)));
            result.emplace_back(Pair("code", statusCode));
            return  result;
        }
        result.emplace_back(Pair("succes", "true"));
        return result;
    }