MT4 / MT5 EA (Expert Advisor) Development

Q: Can you modify an EA I already have?

Yes, if you have the source. We need the.mq4 or.mq5 file, because nobody can edit a compiled.ex4 or.ex5. We also do not decompile other people's work.

MT4 MT5 EA development turns a trading strategy into software that runs it for you. We write it in MQL4 or MQL5, test it before it reaches your account, and deliver the source code so it stays yours.

Bring a finished strategy or only a rough idea. Either way, we build it to your exact specification as a reliable, well-documented tool that you own outright.

What MT4 MT5 EA development actually involves

MT4 and MT5 EA development is more than writing down a strategy. The program has to decide on every tick whether your conditions hold. Then it has to handle every way the broker can say no.

Most of the work is that second half. In fact, the entry logic is usually the smallest part of the file. The time goes on the hard cases instead: a requote, a stop the broker rejects, or a partial fill. Then come a terminal restart mid-trade, a symbol with an odd name and a weekend gap past your stop. An EA that cannot handle those will not survive a live account.

On every tick the EA checks your rules, sizes the trade, checks the broker’s limits and logs the result. Most of the build sits in the last two steps.

MetaQuotes documents the language in its own MQL5 reference. We code to it, and we test every build in MetaTrader itself.

What we need from you to start

You do not need a specification document to begin MT4 and MT5 EA development. Any one of these is enough:

Written rules – even in a chat message, as long as entry, exit and size are clear.
An indicator you already use, with the settings you trade it on.
A Pine Script from TradingView, which we can read and port.
Screenshots of your own trades, marked up with why you took them.
An existing EA that does nearly the right thing, if you have the source.

Where the rules are vague, we ask before we guess. The questions are usually the same three. First, what happens when two signals arrive at once? Second, what if price hits the stop on the same bar as the entry? Finally, what should the EA do when it starts and finds a position already open?

Any one of these five is enough to start. Send what you have, and we will ask about whatever the rules leave open.

No indicator yet? We also do MT4/MT5 indicator development, so the signal can come first and the EA later.

What goes into every Expert Advisor we build

Whatever the strategy, every MT4/MT5 EA development project includes what separates a backtest from live trading:

Lot sizing that is yours – fixed, a percent of balance, or worked back from the stop so each trade risks the same.
Symbol and suffix handling, so the EA works at your broker, not only at ours.
Broker limits handled – minimum stop distance, freeze levels, and lot step rounding that never rounds your risk up.
Recovery after a restart. The EA finds its own positions again after MetaTrader or the VPS reboots, instead of losing track of them.
Daily limits – loss caps, trade counts and trading hours.
A log that says why. When it does not trade, you can read the reason instead of guessing.
Commented source, so the next person to open the file – possibly you – can follow it.

These six parts go into every EA, whatever the strategy. When you review a build, check each one against your own broker.

What a backtest proves, and what it does not

We backtest and optimise every EA before you see it. Still, it is worth being straight about what that proves.

A backtest proves the EA does what the rules say. That has real value, because it catches the logic error, the inverted condition and the stop the code never placed.

It does not prove the strategy will make money. For example, MT4’s default modelling uses interpolated ticks. The spreads in a test are rarely the spreads you will pay. In addition, an optimisation run on the same data that produced the rules will flatter them. So we tell you when a result looks like curve fitting rather than an edge.

If the strategy is yours and you believe in it, that is your call, and we will build it properly. What we will not do is hand you an equity curve as if it were a forecast.

Read a backtest as a check on the code, not as a forecast. Ask us about any result that looks too smooth.

MT4, MT5, or both

MT4 and MT5 EA development means choosing between two languages that look alike but are not. MT4 thinks in orders, while MT5 thinks in positions. MT5 accounts can also run netting or hedging, as MetaTrader’s own guide to orders, deals and positions explains. Indicator access works differently too. So code does not move between them by find-and-replace.

Not sure which to build for? Pick MT5 if your broker offers it and you have no reason not to. Stay on MT4 if you already run there and your broker’s MT5 liquidity is worse. If you need both, say so at the start, because building for both costs less than converting later. We also do MT4 to MT5 conversion as its own job.

Expert Advisors for prop firm accounts

Prop firm rules add limits that an ordinary EA never has to carry. They belong in the code rather than in your head:

Daily loss limits that stop trading before the firm’s line, not at it.
Overall drawdown measured the firm’s way. Some firms measure from balance, some from equity and some from the highest point reached.
News and weekend rules, where the firm forbids holding through them.
Consistency rules, where one huge day disqualifies an otherwise passing account.

Tell us which firm, and we will build to its published rules. Whether the firm allows automated trading at all is its own policy, so read your agreement first.

The four prop firm rules we build into the code. Send us your firm’s published rules, and the EA will stop before each line.

What you receive on delivery

Full source – the .mq4 or .mq5 file, commented.
Compiled EA – .ex4 or .ex5, ready to run.
Set files for the configurations we tested.
Documentation that explains every input in plain language.
A setup walkthrough over WhatsApp or Telegram.
Support after delivery, plus reasonable adjustments.

Everything an MT4 and MT5 EA development project produces is yours outright. We keep no copy running anywhere, and there is no expiry and no per-trade fee. Nothing of ours has to be reachable for it to work, either.

How a project runs

Every MT4 and MT5 EA development project follows the same five steps.

You describe the strategy. Send whatever you have – rules, an indicator, a Pine Script or screenshots – over WhatsApp.
We scope it and quote a fixed price with a timeline, after asking whatever the rules leave open.
We build and test it on backtest and on demo, and show you progress as it goes.
You review it before anything runs on a live account.
We deliver and walk you through setup, then support it afterwards.

Want the bigger picture first? The trading bot development hub lists everything else we build, from Pine Script to Python. For a plan that starts from a manual method, see MT4/MT5 strategy automation.

MT4 MT5 EA development – frequently asked questions

Do I own the code?

Yes. You receive the full commented source, the compiled EA, set files and documentation. We keep no copy running anywhere, and it never needs to reach a server of ours.

Can you build from an indicator or a Pine Script instead of written rules?

Yes. Written rules, an indicator with the settings you trade it on, a Pine Script or screenshots of your own trades are all enough. An existing EA’s source works too. Where the rules are vague, we ask rather than guess.

Will the EA be profitable?

We cannot promise that, and nobody honest can. We build the strategy you specify, correctly and robustly. However, we will tell you when a backtest looks like curve fitting rather than an edge. We build software only, so we do not sell signals or manage money.

Should I build for MT4 or MT5?

Pick MT5 if your broker offers it and you have no reason not to. Stay on MT4 if you already run there. If you need both, say so at the start, since building for both costs less than converting afterwards.

Can you build an EA that respects prop firm rules?

Yes. The code can enforce daily loss limits and overall drawdown measured the way your firm defines it. It can also follow news, weekend and consistency rules. Whether the firm allows automation at all is its own policy, so read your agreement.

What happens if MetaTrader or the VPS restarts?

The EA finds its own positions again on startup instead of losing track of them. That is part of every build, whatever the strategy.

Can you modify an EA I already have?

Yes, if you have the source. We need the .mq4 or .mq5 file, because nobody can edit a compiled .ex4 or .ex5. We also do not decompile other people’s work.

How long does it take?

Most MT4 and MT5 EA development projects land between a few days and a couple of weeks, depending on complexity. You get a timeline along with the fixed quote.

Do you support it after delivery?

Yes. We support the EA after delivery, and we make reasonable adjustments too.

Do you have ready-made tools for MetaTrader?

Yes, for copying trades rather than running a strategy. The Telegram to MT4/MT5 copier places channel signals on your account. The MT4 to MT5 copier mirrors one account to others. For your own rules, a custom EA is still the answer.

How much does MT4 MT5 EA development cost?

It depends on the strategy: how many conditions, how much position management, and whether it needs both platforms. Tell us what it should do, and we will quote a fixed price with a timeline. Ask for a quote.