MQL5 Developer for EAs, Indicators and C++ Integration
When the work is in the code itself, such as porting an MT4 EA to MT5, finding why an EA trades differently live, or connecting MetaTrader to C++ or Python, you need a developer who knows both MQL and the systems around it. Our team writes MQL5 and MQL4 every day alongside the C++ engine we run in production.
MQL work we take on
- MQL4 to MQL5 porting
- MT4 EAs and indicators rewritten for MT5: the new order and position model, netting and hedging accounts, and event handling, checked side by side in the tester.
- Code audits
- A written review of an existing EA: order handling, error checks, risk logic, look-ahead bias in backtests, and anything that will behave differently on a live broker.
- Fixes and refactoring
- Order errors, requotes, slippage handling, frozen trades and memory or speed problems, fixed without changing the strategy logic unless you ask.
- Custom indicators and scripts
- Indicators, multi-timeframe and multi-symbol tools, trade managers, dashboards and alerts for MT5 and MT4.
- C++ DLL and Python bridges
- Heavy calculations moved into a C++ DLL, or MetaTrader connected to Python models and external data, with the error handling a live account needs.
- Strategy tester work
- Real-tick test set-ups, custom optimisation criteria and test reports you can compare across versions.
How we work on existing code
- 01
Read the code
You send the source and describe the problem or the goal. We read it before quoting, so the quote reflects the real state of the code.
- 02
Written findings
For audits and fixes we list what we found and what we propose to change, in plain language, before changing anything.
- 03
Change and test
Changes are made in small steps and checked in the strategy tester against the previous version.
- 04
Demo forward test
Where behaviour on a live broker matters, the new version runs on a demo account before you use it.
- 05
Handover
Updated source, compiled files, a change log and the test reports.
What you receive
- Updated MQL5 or MQL4 source code and compiled files
- A written audit or change log
- Strategy tester reports, before and after
- Demo forward-test log where relevant
- Bug-fix support after delivery
Why QuantFX for MQL5 work
- MQL plus C++
- We build a C++ trading engine as well as MQL code, so DLLs, bridges and performance work are in-house.
- We run strategies ourselves
- Our master strategy account trades on MT5, so live-versus-tester differences are a daily concern, not a theory.
- You own the code
- Everything we write or change is delivered as source. No locked files, no licence servers.
- Clear scope
- Fixed quotes against written findings, and a UK company behind the work: QUANT-FX INFRASTRUCTURE LTD.
Typical audit findings
The problems we find most often in existing EAs are orders sent without checking the broker's stops-level, no handling of requotes or partial fills, lot sizes not normalised to the symbol, and backtests that read the current bar's close before it exists.
Each of these can make an EA look fine in the tester and behave differently live. An audit lists them with the line of code and the fix.
How pricing works
Porting, audits and fixes are quoted at a fixed price after we have read the code. New indicators and tools are quoted against a short specification. Larger integrations, such as a C++ DLL or a Python bridge, are scoped with you first.
Frequently asked questions
- Can you convert my MT4 EA to MT5?
- Yes, if you have the .mq4 source code. MT5 uses a different order and position model, so the conversion is a rewrite of the trading logic, which we test against the MT4 version.
- Can you work from a compiled .ex4 or .ex5 file?
- No. We need the source code. If you only have the compiled file, we can rebuild the EA from a description of its rules.
- Do I keep ownership of the code you change?
- Yes. You receive the full updated source code.
- Can MetaTrader call a C++ or Python model?
- Yes. MQL5 can call functions in a C++ DLL, and can exchange data with Python through files, sockets or a bridge. We build and test both sides.
Have MQL code that needs porting, fixing or connecting? Send it over with a short description and we will come back with findings and a fixed quote.
Send us your code or briefTrading leveraged products such as CFDs and FX carries a high risk of loss. QuantFX provides software development services only; we do not give investment advice and do not hold or manage client funds.