Crypto Exchange Integration with MQL5 (Part 1): Connecting to MEXC Futures
This article introduces the foundations of connecting MetaTrader 5 to a cryptocurrency exchange using MQL5 and the MEXC Futures API. It covers terminal configuration, JSON response processing, WebRequest() execution and validation, and conversion of API data into native MQL5 types. Practical examples demonstrate retrieving and processing exchange data. These components establish the basis for a reusable MEXC Futures client, developed progressively throughout the series. The series focuses exclusively on exchange integration; how readers use the retrieved data remains outside its scope.
Practical Modules from Other Languages in MQL5 (Part 07): The OS Module from Python
This article introduces a lightweight OS-like helper for MQL5 that streamlines file and path operations using a Python-inspired interface. We implement getcwd, listdir, scandir with DirEntry, remove, rmdir, rename, mkdir, stat, and an os.path subset (exists, isfile, isdir, join, split, pardir). You will learn how to work consistently within the terminal Files/common sandbox and simplify everyday filesystem tasks.
How MQL5 Lite MCP AI Assistant Changed My Debugging Approach on Generated MQL5 Codes
This article presents a practical debugging workflow with MetaEditor's integrated AI Assistant and a comparison to the previous external approach. We fix a controlled set of syntax and API errors in a D1 PriceMarker EA, inspect modifications, and recompile. The result is validated in the Strategy Tester, with clear boundaries between compilation success and required runtime checks.
Creating a Cairo-Inspired Graphics Library for MetaTrader 5 (Part 4): Anti-Aliasing, Coverage and Compositing
The rasterizer now accumulates exact span coverage in X and sampled coverage in Y, and blends it via CairoBlendOver on straight ARGB. CairoAaSamples sets the number of vertical samples at runtime, making the cost nearly linear and localized to edges. Readers get smoother boundaries, correct compositing of translucent shapes, and controllable performance.
Building a PDF Creation Library in MQL5 (Part1): Writing a PDF by Hand
This article shows how a PDF works as plain text by hand‑written two files: a 592‑byte page and an 885‑byte trade ticket. It explains the file structure (header, body, xref, trailer), the required page objects and resources, and the operators that draw text, then provides an MQL5 script to generate them. First part of a pure‑MQL5 PDF library series.
Try/Catch style in MQL5: Bringing Modern Error Management to Algorithmic Trading
This article presents an exception-like model for MQL5 that prevents VM faults through defensive guards and cooperative TRY/CATCH/FINALLY macros. It introduces structured error objects (CException), result propagation (CResult), manual stack tracing, and integrated logging for clear diagnostics. Readers learn how to validate risky operations, propagate failures predictably, and keep EAs stable when facing zero‑divide, null access, invalid handles, and array‑bounds conditions.
Market Simulation: Position View (XI)
In this article, I will show you, dear reader, how to select the objects we create on the chart and modify the position indicator so that it can perform many more functions than originally intended. We will look at how to implement the ability to move price levels and create price lines directly on the chart. Many people may find this difficult. However, you will see that we'll do this with minimal effort. You just need to give it a little thought.
Creating a Cairo-Inspired Graphics Library for MetaTrader 5 (Part 2): Points, Contours and the Path
This second part adds the geometry layer to a Cairo‑inspired graphics library for MetaTrader 5. It defines a path of double‑precision points grouped into contours, records open/closed intent, and stores vertices in a flat array with start indices. We implement MoveTo, LineTo, Close, provide basic shape helpers, and include a demo that visualizes the built geometry for inspection and reuse.
Beyond Clone and Commit: The Advanced Side of MQL5 Algo Forge
We map the parts of Algo Forge that impact day-to-day MQL5 work: opening repos in MetaEditor, README translation, Units, branch/tag protection, browser patching, packages, and CI on a Windows host. The article shows exact settings, required runner labels, and how to gate merges on builds. You leave with reproducible steps to protect code, automate compiles, and ship artifacts.
Creating a Cairo-Inspired Graphics Library for MetaTrader 5 (Part 5): Fill Rules, Holes and Borders
Part 5 adds a fill rule to the rasterizer and a stroke helper to the path. The engine now supports both non-zero and even-odd fills via a single enum parameter, enabling rings, true borders that do not repaint interiors, and glyph counters. AddThickLine() builds strokes from fills in one path and one pass, preserving uniform opacity at joints and showing why strokes require the non-zero rule.
Market Replay: Unity Is Strength (II)
Until now, the application being developed as part of this series of articles has focused exclusively on simulating the graphical part. However, to obtain a more complete system in which we can test the Expert Advisor within the replay/simulation service, we also need to simulate the trading server. You'll notice that this simulation will include only the most essential elements. Nevertheless, you, dear reader, will be able to fill in the missing parts. Since these additional components don't affect what I want to show, we already have more than enough to implement what we have in mind.
Creating a Cairo-Inspired Graphics Library for MetaTrader 5 (Part 6): Curves and Adaptive Flattening
This part introduces cubic Bézier curves and a quadratic verb, flattened on append by recursive midpoint splitting (De Casteljau). A conservative flatness test sums distances of control points to the chord and stops within a pixel-based tolerance, adapting detail to curvature. The design keeps downstream code intact while giving you efficient, scale-independent curve quality.
Recovering Option-Implied Probability Distributions Across Four Markets in MQL5
A practical route from the option chain to probability levels inside MetaTrader 5. For GLD, SLV, SPY, and USO, the risk-neutral density implied by each ETF's options is recovered with the Breeden-Litzenberger identity and checked for static arbitrage, after the method itself is validated against an analytic lognormal. A Python feed publishes the percentiles; an MQL5 service rescales them onto a related symbol, draws levels, and alerts when price leaves the risk-neutral 5 to 95 percent band. Every reading carries its own diagnostics, and full source is included.
Market Simulation: Position View (XVI)
In this article, we will make the necessary changes so that the position indicator displays the financial result. This way, the trader will be able to get an idea of the financial result of an open position. In addition, I will tell you something that many people do not know, even those who have been using MQL5 for a long time: how to use static variables to share memory and avoid declaring a global variable in the main code.
Market Replay: Unity Is Strength (I)
We're entering the home stretch. The development of the replay/simulation system is nearly complete. Of course, we still have a few things left to finish, but compared to everything we've already done, completing what's left won't be difficult. However, it is essential to fully absorb and understand everything covered in this article. So I hope you enjoy reading this and, above all, that you enjoy this final stage of the journey.
The MQL5 Standard Library Explorer (Part 18): Building a Multi-Symbol Indicator Cache
The article introduces a centralized cache that serves indicators to multiple strategy nodes. It encodes full indicator identity in keys, stores Standard Library objects in CArrayObj entries, reuses matching instances, verifies readiness, refreshes data, and deletes each indicator on final release. Readers gain a predictable resource lifecycle and reduced duplication in multi‑symbol Expert Advisors.
Beyond REST and ZeroMQ: Building a gRPC/Protocol Buffers Bridge for Real-Time MetaTrader 5–Python Inference
This article defines a Protocol Buffers contract for the MetaTrader 5-Python boundary and implements a length-prefixed Protobuf-over-TCP client in MQL5, since MQL5 cannot speak real gRPC natively. A small Python shim relays those frames to a genuine grpc.aio server, unary today, with streaming already live on the backend. You get schema-enforced, strongly-typed messages, explicit errors, retry/backoff, and a Strategy Tester cache for reproducible backtests where sockets don't run.
Creating a Cairo-Inspired Graphics Library for MetaTrader 5 (Part 7): Arcs, Circles and Rounded Rectangles
This part finishes the geometry layer: arcs use a sagitta‑based angular step tied to the pixel tolerance, so segment counts are computed, not guessed. The path gains ArcTo, AddCircle, AddEllipse and AddRoundRect with per‑corner radii, enabling common UI shapes such as tabs, pills, badges, rings, gauges and donut wedges.
The MQL5 Standard Library Explorer (Part 17): Building a Reusable Portfolio Manager with CArrayObj
We present a multi‑symbol EA structure that moves symbol‑specific state into independently initialized CStrategyNode objects and manages them with CPortfolioManager. Using CArrayObj with FreeMode, Add(), At(), Delete(), Total(), and Clear(), the manager ensures safe ownership and isolation, while timer‑driven routing and completed‑bar gates keep processing deterministic. This lets you scale portfolios, control risk per node, and avoid duplicated event handling.
Practical Modules from Other Languages in MQL5 (Part 09): MATPLOTLIB (II)
Learn how to create advanced visualizations in MetaTrader 5 using a Matplotlib-like API from MQL5 while Python handles rendering. We implement key chart types—scatter, bar, horizontal bar, histogram, pie, and hexbin—and show how to control axes, legends, colorbars, and styles. The result is a consistent workflow for exploring trading and financial datasets.
Building a PDF Creation Library in MQL5 (Part 2): Why PDFs Break
Learn how a viewer opens a PDF backwards, why xref entries must be exactly 20 bytes, and how a two-character change falsifies multiple offsets. We reproduce three typical failures, compare results in PDFium and pypdf, and extract four strict checks a generator must pass. The included PdfValidate.mqh class for MQL5 applies these checks and returns actionable offsets and object numbers for reliable testing beyond “it opens”.
Zero-Copy Tick Streaming (Part 2) : Reading MetaTrader 5 Ticks into Python and Benchmarking the Result
We build a Python reader that attaches to the MetaTrader 5 shared memory segment, reproduces the Arrow columnar layout, and constructs ArrowArray/ArrowSchema via ctypes so pyarrow imports ticks without copying. The code honors the three-way schema contract and the seqlock generation counter to read consistent batches. A standalone benchmark verifies performance against a legacy per-field struct.unpack path with real numbers.
Using the MQL5 Economic Calendar for News Filter (Part 5): The Tier the Calendar Does Not Have
This part extends the news filter with an ordered tier scale that adds a special tier above the broker's High, per‑event time windows, and one classifier shared by live calendar data and historical CSV. A rule table (with optional CSV overrides) promotes or demotes specific releases and can set custom windows. A diagnostic script prints your broker's calendar, event codes, and server time so your rules match what the terminal actually reports.
Market Simulation: First Steps with SQL in MQL5 (II)
Although many people believe that we can easily embed SQL code into other code, this is usually not the case. The reason is that the SQL code is included in the executable as a string. Embedding SQL code as a string, while not a problem for small snippets, can ultimately cause us quite a few headaches.
Market Simulation: First Steps with SQL in MQL5 (III)
In the previous article, we looked at an example of implementing a class in MQL5 to provide basic support. Its purpose is specifically to allow SQL code to be stored in a separate script file. This way, we won't need to write the same SQL statements as string literals in the MQL5 source code. Although this solution is functional, there are some aspects of it that we can and should improve.
Building a PDF Creation Library in MQL5 (Part 3): The Byte-Exact Writer
The article presents CPdfBuffer and CPdfWriter, a minimal MQL5 pair that derives all offsets from the output buffer instead of hand-maintaining numbers. CPdfWriter records object starts, writes a fixed-width cross-reference table and trailer, and ensures structural consistency. The result passes Part 2's validator, and a ready-to-use script converts arbitrary text to a paginated PDF.