OpenAlgo MQL5 Functions

Below is the API documentation for the OpenAlgoAPI functions provided in your MQL5 header file:

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OpenAlgoAPI Function Documentation

All six functions are void. They print the request and the OpenAlgo response to the Experts log rather than returning a value, so read the log (or the OpenAlgo order book) to confirm what happened.

Each function takes apiUrlParam as the base URL of your OpenAlgo instance, for example http://127.0.0.1:5000, and appends the endpoint path itself.

PlaceOrder

Places an order with the specified parameters by sending a POST request to /api/v1/placeorder.

void PlaceOrder(string actionParam,
                int quantityParam,
                string apiUrlParam,
                string apiKeyParam,
                string strategyParam,
                string symbolParam,
                Exchanges exchangeParam,
                ProductTypes productParam,
                PriceTypes priceTypeParam,
                double priceParam = 0,
                double triggerPriceParam = 0,
                int disclosedQuantityParam = 0)

Parameters:

• actionParam: The trade action, either "BUY" or "SELL".

• quantityParam: The quantity of the asset to trade, in units and not lots.

• apiUrlParam: The base URL of the OpenAlgo API.

• apiKeyParam: The OpenAlgo API key, generated on the API Key page of the dashboard. This is not your broker's API key.

• strategyParam: The name of the trading strategy. OpenAlgo records it against every order.

• symbolParam: The OpenAlgo symbol for the instrument being traded.

• exchangeParam: An Exchanges enum value (NSE, NFO, CDS, BSE, BFO, BCD, MCX, NCDEX).

• productParam: A ProductTypes enum value (CNC, NRML, MIS).

• priceTypeParam: A PriceTypes enum value (MARKET, LIMIT, SL, SLM). SLM is sent as SL-M.

• priceParam (optional): The price at which to place the order. Required for LIMIT and SL.

• triggerPriceParam (optional): The trigger price for SL and SL-M orders.

• disclosedQuantityParam (optional): The disclosed quantity of the order.

The three optional numeric parameters are only written into the JSON body when they are greater than zero, so leaving them at their defaults keeps the payload minimal.

Usage:

PlaceOrder("BUY", 10, "http://127.0.0.1:5000", "your_api_key", "Meta Strategy", "SBIN", NSE, MIS, MARKET);

PlaceSmartOrder

Places an order that considers the current open position size and matches the position size given in the position book. Sends a POST request to /api/v1/placesmartorder.

void PlaceSmartOrder(string actionParam,
                     int quantityParam,
                     int positionSizeParam,
                     string apiUrlParam,
                     string apiKeyParam,
                     string strategyParam,
                     string symbolParam,
                     Exchanges exchangeParam,
                     ProductTypes productParam,
                     PriceTypes priceTypeParam,
                     double priceParam = 0,
                     double triggerPriceParam = 0,
                     int disclosedQuantityParam = 0)

Parameters:

• Inherits all parameters from PlaceOrder.

• positionSizeParam: The target position size. It sits third, immediately after quantityParam.

OpenAlgo compares positionSizeParam with your live open position for that symbol, exchange and product, then places only the difference. A target of 0 flattens the position, and in that case OpenAlgo works out the direction itself, so actionParam and quantityParam are ignored. If the position already matches the target, no order goes to the broker.

Usage:

PlaceSmartOrder("SELL", 5, 10, "http://127.0.0.1:5000", "your_api_key", "ReversalStrategy", "TATASTEEL", NSE, MIS, LIMIT, 150.00);

ModifyOrder

Modifies an existing order with new parameters. Sends a POST request to /api/v1/modifyorder.

void ModifyOrder(string orderidParam,
                 string actionParam,
                 int quantityParam,
                 double priceParam,
                 string apiUrlParam,
                 string apiKeyParam,
                 string strategyParam,
                 string symbolParam,
                 Exchanges exchangeParam,
                 ProductTypes productParam,
                 PriceTypes priceTypeParam,
                 int disclosedQuantityParam = 0,
                 double triggerPriceParam = 0)

Parameters:

• orderidParam: The ID of the order to be modified, as returned by OpenAlgo when the order was placed.

• priceParam: Mandatory here, unlike in PlaceOrder. It sits fourth, right after quantityParam.

• The remaining parameters match PlaceOrder.

Note the tail of the argument list: in ModifyOrder the optional disclosedQuantityParam comes BEFORE triggerPriceParam, which is the reverse of PlaceOrder and PlaceSmartOrder. /api/v1/modifyorder requires every field, so this function always sends price, quantity, disclosed quantity and trigger price, even when they are zero.

Usage:

ModifyOrder("123456789", "BUY", 10, 155.00, "http://127.0.0.1:5000", "your_api_key", "Meta Strategy", "YESBANK", NSE, CNC, LIMIT);

CancelOrder

Cancels an existing order. Sends a POST request to /api/v1/cancelorder.

void CancelOrder(string orderidParam,
                 string apiUrlParam,
                 string apiKeyParam,
                 string strategyParam)

Parameters:

• orderidParam: The ID of the order to be canceled.

• apiUrlParam: The base URL of the OpenAlgo API.

• apiKeyParam: The OpenAlgo API key.

• strategyParam: The name of the trading strategy.

Usage:

CancelOrder("123456789", "http://127.0.0.1:5000", "your_api_key", "Meta Strategy");

ClosePosition

Closes all open positions associated with a given strategy. Sends a POST request to /api/v1/closeposition.

void ClosePosition(string apiUrlParam,
                   string apiKeyParam,
                   string strategyParam)

Parameters:

• apiUrlParam: The base URL of the OpenAlgo API.

• apiKeyParam: The OpenAlgo API key.

• strategyParam: The name of the trading strategy to close positions for.

Usage:

ClosePosition("http://127.0.0.1:5000", "your_api_key", "Meta Strategy");

CancelAllOrders

Cancels all orders associated with a given strategy. Sends a POST request to /api/v1/cancelallorder.

void CancelAllOrders(string apiUrlParam,
                     string apiKeyParam,
                     string strategyParam)

Parameters:

• apiUrlParam: The base URL of the OpenAlgo API.

• apiKeyParam: The OpenAlgo API key.

• strategyParam: The name of the trading strategy to cancel orders for.

Usage:

CancelAllOrders("http://127.0.0.1:5000", "your_api_key", "Meta Strategy");

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Notes

• Replace placeholder values like "your_api_key" and "http://127.0.0.1:5000" with the actual key and URL for your setup.

• symbolParam is the OpenAlgo symbol, not the MetaTrader symbol. Equities carry no -EQ suffix, so use SBIN, not SBIN-EQ.

• The transport is wininet.dll, so Allow DLL imports must be enabled for the EA. MQL5's WebRequest() allowlist is not involved.

• OpenAlgo rate limits order placement to 10 requests per second. Guard your EA against firing on every tick.

• This library covers order management only. Market data, the order book, positions and holdings are reached by calling the OpenAlgo REST API directly.