C++ has been my favorite language for a while now. Despite its popularity due to its speed and capabilities of memory management, MetaQuotes has never released an official API so the users could work with it.
Well, if it was a problem for someone, it is no longer.
MQL++ allows the user fetch the data from the MQL5::Metatrader5 terminal to work with it directly with it, aswell as to send orders to the trade server via C++ code.
In simple terms, the MQL++ library calls the functions exposed by the Python API provided by MetaQuotes, which are just a bunch of C functions under the hood.
Follow these steps to correctly use the library:
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Install a Python version (I would recommend the version 3.10 or later);
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Run the CMD as admin and run the following command to install the Metatrader5 module: pip install Metatrader5;
2.1. Although the Metatrader5 module already uses it, you may have to install a numpy version compatible to it. If any error occurs, you may have to also run the command pip install "numpy<2.0" to install the numpy module.
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Create a new project and add the Metatrader5 folder, which contains the lib, to your project folder. Also, set it to compile with C++20 (/std:c++20)
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Add the Python include and lib and also the numpy include directories to your project, so it can look for the required libraries.
4.1. If you used the default installation path for Python, both are probably the following locations:
- C:\Python310\include
- C:\Python310\libs
- C:\Python310\Lib\site-packages\numpy\core\include
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After that, you should be ready to start coding with MQL++.
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When your program is ready, before you run it, you must open the Metatrader 5 terminal (otherwise the Init function will fail) and login to any account (otherwise the Login function will fail). After you call Login in your code, it'll automatically switch to that account in the terminal.
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If you want to use the library on an application written in another language, just compile the library as a dll or download the latest release and import its function on your project. You'll find a single file example in the Examples/MQL++_4CSharp folder on how to declare MQL++ structures in C# and how to import its functions from the compiled DLL.
In the Examples/* folder there'll be some examples on how to use the classes for more convenience when trading. You still can use the functions directly, though.
Almost every function exposed by the Python API provided by MetaQuotes can be called from MQL++ using the same arguments (in the future, the remaining functions will be added). Here are examples on how to call some available functions and how to use their data:
Initializes the python environment. Must be called before any other function. Errors are immediately printed to the console. This behavior is subject to change in future versions.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
int main(int argc, char** argv)
{
if(Mt5::InitPyEnv() == false)
{
return 0; // if this function fails, calling GetLastError won't help. Instead, the error is directly printed to the console - although errors are really rare.
}
}Estabilishes a connection with the open MQL5::Metatrader5 terminal. In case of an error, the function returns 'false' and the last_error variable is set. If this occurs, a description of the error can be retrieved using the function LastError. If you close the terminal, you need to call Init again once it is reopened.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
int main(int argc, char** argv)
{
// Python environment already initialized...
if(Mt5::Init()==false)
{
MqlErrorInfo err;
Mt5::GetLastError(err);
std::cout << err.desc;
std::cin.get();
return 0;
}
}Sends a login request to the terminal. In case of an error, the function returns 'false' and the last_error variable is set. If this occurs, a description of the error can be retrieved using the function LastError.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
int main(int argc, char** argv)
{
// Python environment already initialized...
// Connection to the terminal already estabilished
ulong login = 123456789;
std::string pwd = "MyPwd";
std::string sv_name = "MetaQuotes-Demo";
if(Mt5::Login(login, pwd.c_str(), sv_name.c_str())==false)
{
std::cout << "Login failed.\n";
MqlErrorInfo err;
Mt5::GetLastError(err);
std::cout << err.desc;
std::cin.get();
return 0;
}
}Gets the last error. If the program continues and the error was already handled, the user must call MQL5::Metatrader5::Release on the MqlLastError object to clean it up.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
int main(int argc, char** argv)
{
// Python environment already initialized...
// Connection to the terminal already estabilished
if(Mt5::Login(login, pwd.c_str(), sv_name.c_str())==false)
{
std::cout << "Login failed.\n";
MqlErrorInfo err;
Mt5::GetLastError(err);
std::cout << err.desc;
Mt5::Release(err);
}
// do something after the error occurred, but does not end the program.
}Copies the rates (bars) of a certain symbol in the specified timeframe from the range "date_from" to "date_to" and saves it in the MqlRatesContainer variable. Notice the use of string as date in the format "DD.MM.YYYY" or "DD.MM.YYYY HH:MM:SS", followed by the user-defined literal '_dt' to convert it to a datetime type. Finally, the prints the MqlRatesContainer to the console.
The data is placed in the container from the oldest bar (index 0) to the newest bar (index 'size-1'). date_from may be 0 to copy the data from the first bar; date_to can be MAX_DATETIME to copy all bars up to the newest one.
After the container is not necessary anymore, call MQL5::Metatrader5::Release to clean it up.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
void PrintRates(std::string symbol)
{
MqlRatesContainer rates;
long total = Mt5::CopyRatesRange(symbol.c_str(), TIMEFRAME_H1, "26.07.2023"_dt, "27.07.2024"_dt, rates);
for (long i = 0; i < total; ++i)
{
std::cout << rates[i] << '\n';
}
MQL5::Metatrader5::Release(rates);
}Similar to MQL5::Metatrader5::CopyRatesRange, but copies the ticks in the range 'date_from' to 'date_to'.
After the container is not necessary anymore, call MQL5::Metatrader5::Release to clean it up.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
void PrintTicks(std::string symbol)
{
MqlTickContainer ticks;
long total = Mt5::CopyTicksRange(symbol.c_str(), TIMEFRAME_H1, "26.07.2023"_dt, "27.07.2024"_dt, ticks);
for (long i = 0; i < total; ++i)
{
std::cout << ticks[i] << '\n';
}
MQL5::Metatrader5::Release(ticks);
}Copies 'count' ticks to the past, starting from the 'date_from' date. The data is arranged in the destination container from the oldest tick (index 0) to the newewst tick (index 'size-1').
Although not documented by the MQL docs, the date_from parameter must be lower or equal than the last received tick time; otherwise, no error returns after calling GetLastError, but no data is copied. The last tick information can be retrieved by calling MQL5::Metatrader5::SymbolInfoTick.
After the container is not necessary anymore, call MQL5::Metatrader5::Release to clean it up.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
void PrintTicks(std::string symbol)
{
MqlTickContainer ticks;
long total = Mt5::CopyTicksRange(symbol.c_str(), TIMEFRAME_H1, "26.07.2023"_dt, "27.07.2024"_dt, ticks);
for (long i = 0; i < total; ++i)
{
std::cout << ticks[i] << '\n';
}
MQL5::Metatrader5::Release(ticks);
}Copies the last tick data received by the MQL5::Metatrader5 terminal. Returns false in case of an error, which is either directly printed to the console (in the case of a Python error) or stored in the last_error variable.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
void PrintLastTick(std::string symbol)
{
MqlTick tick;
Mt5::SymbolInfoTick(symbol.c_str(), tick);
std::cout << tick << "\n";
}Sends an order request to the trade server. As a result, it returns a MqlTradeResult structure that contains the result of the trade order.
The MqlTradeRequest must be filled as the documentation shows.
Returns false in case of a failure. Check the MqlTradeResult::retcode member for more details about the failure.
Whenever MqlTradeRequest and MqlTradeResult structures are not necessary anymore, you should call MQL5::Metatrader5::Release to clean them up. The only exception is to calling Release on a MqlTradeRequest that has its const char* members (symbol and comment) set by a pointer that was not directly allocated by new. In this case, Release either should not be called on MqlTradeRequest, as in the example below, or should have its const char* members deallocated and set to nullptr beforehand.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
void Buy(std::string symbol)
{
MqlTradeRequest req{};
MqlTradeResult res{};
req.action = TRADE_ACTION_DEAL;
req.magic = 1337;
req.symbol = symbol.data(); // safe to use like this, as the 'symbol' object is only deleted at the end of the scope
req.type = ORDER_TYPE_BUY;
req.volume = 0.01;
req.type_filling = ORDER_FILLING_IOC;
Mt5::OrderSend(req, res);
if(res.retcode == 10009)
{
std::cout << "Successful.\n";
}
else
{
std::cout << "Error: " << res.retcode << '\n';
}
//Mt5::Release(req); // in this case, the 'comment' member was not set, and 'symbol' was a pointer already managed by the std::string. Release should not be called.
Mt5::Release(res);
}Gets all deals in a certain date range and returns it in a MqlDealInfoContainer. The user can specify 0 for the date_from parameter and MAX_DATETIME for the date_to parameter to retrieve the entire deals list.
Returns -1 in case of an error.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
int main(int argc, char** argv[])
{
// initialization functions...
MqlDealInfoContainer deals;
if (Mt5::HistoryDealsGet(0, MAX_DATETIME, deals) <= 0)
{
MqlErrorInfo err;
Mt5::GetLastError(err);
std::cout << err << '\n';
return 0;
}
std::cout << deals[deals.Size()-1] << '\n';
}Gets all open positions and stores the value in a MqlPositionInfoContainer. Returns the number of open positions on success and -1 in case of an error.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
int main(int argc, char** argv[])
{
// initialization functions...
MqlPositionInfoContainer positions;
if (Mt5::PositionsGet(positions) <= 0)
{
MqlErrorInfo err;
Mt5::GetLastError(err);
std::cout << err << '\n';
return 0;
}
std::cout << positions[positions.Size()-1] << '\n';
}Gets all open positions and stores the value in a MqlOrderInfoContainer. Returns the number of open positions on success and -1 in case of an error.
using namespace MQL5;
using Mt5 = MQL5::Metatrader5;
int main(int argc, char** argv[])
{
// initialization functions...
MqlOrderInfoContainer orders;
if (Mt5::OrdersGet(orders) <= 0)
{
MqlErrorInfo err;
Mt5::GetLastError(err);
std::cout << err << '\n';
return 0;
}
std::cout << orders[orders.Size()-1] << '\n';
}MQL5 is a rich and complete language to develop financial analysis and trading tools. The goal of MQL++ is to come as close as possible to the MetaQuotes language in terms of how to interact with Metatrader5 terminal, aswell as to become a complete library to analyze data and develop trading strategies.
If you're willing to contribute to this project, please get in touch with me. If you want to support its development, please check out my Expert Advisor Emerald EA Builder, available in the MetaQuotes market.