 <h2>Initial note</h2> <p>A lot of indeed <strong>smart</strong> man*years has been burnt on reverse-engineered efforts to tap into <strong><code>MT4/Server</code></strong> &lt;--> <strong><code>MT4/Terminal</code></strong> C/S communication.</p> <p>Some have died by themselves.</p> <p>Some have failed to survive the next change introduced by just another Build XYZ.</p> <p>Some have even made their way up to the court suits from MetaQuotes, Inc., for violation or infringements of the rights to protect one´s intellectual property.</p> <p>So, one shall rather really know, what is going to follow.</p> <h2>How it works?</h2> <p>Recent <strong><code>MT4/Terminal</code></strong> Build 670+ uses several regular streaming connections to <strong><code>MT4/Server</code></strong></p> <p>It does not take much time or efforts to employ a port-scanner of whatever brand to map, decode and analyse further internals. Nevertheless, do not rather forget the warning, [<strong>Initial note</strong>] rulez.</p> <p>There are <strong>no direct ways</strong> to "update" OHLC-candle / Volume objects of the <strong><code>MT4/Terminal</code></strong> graph</p> <p>There are <strong>many ways</strong> to add and control additional visual objects into the MT4 graphs, incl. but not limited to, compose a fully-fledged new, layered, augmented GUI, where user-defined &lt;<em><strong>application-code</strong></em>> retains the full real-time control of both the <strong><code>MVC-GUI</code></strong>-elements and the <strong><code>TradingExecutionEngine</code></strong>.</p> <h2>Can a current Metatrader proprietary architecture get extended?</h2> <p><strong>Yes.</strong></p> <p>Historically some three principal epochs / approaches were used.</p> <ol> <li><p>3rd party DLL based communications</p></li> <li><p>Windows O/S services based communications</p></li> <li><p>MetaQuotes, Inc., "new"-MQL4 ( post Build 600+ ) language extensions for socket communications</p></li> </ol> <p>User-defined &lt;<em><strong>application-code</strong></em>> can safely deploy rather a thread-safe external messaging infrastructure, to better "escape" from a (fragile, namely in post Build 670+ epoch) MT4 internalities and retain a full control over the "own" messaging / streaming layer.</p> <h2>Examples</h2> <p><strong><code>MT4/Terminal</code></strong> with socket/remote <strong><code>python</code></strong>-based CLI terminal &amp; add-on pseudo-language for both trading and scripted test-case batteries´ automated runs</p> <p><strong><code>MT4/Terminal</code></strong> with socket/remote external integrated RSS-feed service</p> <p><strong><code>MT4/Terminal</code></strong> with socket/remote GPU-hosted numerical solver for AI/ML decision making</p> <p><strong><code>MT4/Terminal</code></strong> with socket/remote cloud-based peer-to-peer community messaging</p>