MT5 Order Preflight - Read-Only Validation - script for MetaTrader 5

Purpose

MT5 Order Preflight is a read-only diagnostic script for checking a hypothetical market, limit or stop order against the rules currently advertised for the chart symbol. It helps isolate common request problems before the same values are tested inside a larger Expert Advisor.

The script never sends, modifies or cancels a trade. It creates a plain-text validation report in the Experts tab and, optionally, in the terminal-wide Common\Files folder.

What it checks

• availability of a current Bid and Ask tick;
• symbol trade mode and long-only, short-only or close-only restrictions;
• support for market, limit or stop orders;
• minimum, maximum and step-aligned volume;
• tick-size normalization of a hypothetical pending price;
• pending-order distance against the current stops level;
• stop-loss and take-profit support and minimum distance;
• advertised FOK, IOC or BOC filling flags.

How to use

1. Copy SCA_MT5OrderPreflight.mq5 to MQL5\Scripts\StratCoreAlpha and compile it.
2. Run the script on the symbol that exhibits the order problem.
3. Select the hypothetical order scenario, volume and distances.
4. Review every PASS, WARN and FAIL line in the Experts tab or saved text report.
5. Add the actual trade retcode and nearby Experts or Journal lines when preparing a reproducible bug report.

Inputs

• InpScenario — market buy/sell, buy/sell limit or buy/sell stop.
• InpVolume — hypothetical order volume.
• InpPendingDistancePoints — pending distance from the current Ask or Bid.
• InpStopLossPoints and InpTakeProfitPoints — protective distances; zero disables the corresponding check.
• InpWriteTextFile and InpPrintToExperts — report destinations.
• InpFilePrefix — prefix for the Common\Files text report.

Reading the result

PASS means the supplied value is consistent with the inspected symbol metadata. WARN identifies a disabled or broker-dependent check that needs review. FAIL means the hypothetical request conflicts with at least one current rule.

[PASS] Volume range: 0.10000000 is inside the advertised range. [PASS] Volume alignment: 0.10000000 matches step 0.01000000. [FAIL] Stop loss distance: 5 points is below the current stops level of 20. Result: DO NOT SEND AS CONFIGURED

Privacy and safety

The report excludes account login, owner name, broker server, balance, equity, positions, orders, history, files, keys and credentials. Review the generated text before sharing it.

A passing preflight cannot guarantee trade-server acceptance, execution price or trading results. Market state and broker rules can change between the diagnostic run and a later request.

Source and license

The source is released under the MIT License. The versioned source and installation guide are available at the public GitHub release.