Trading platforms are not just about charts and order buttons. The best traders write their own tools — custom indicators that spot patterns no off-the-shelf tool sees, automated robots that execute strategies while they sleep, and scripts that handle the repetitive work that takes hours by hand.
For that, you need a scripting engine. Not a plugin system, not a macro recorder — a real programmable environment that gives you full control over the platform.
BS Trader includes one. It is called BSL, and it was designed from the ground up to be familiar to anyone who has written trading code before, while being genuinely modern underneath.
What BSL Does
BSL runs inside the Desktop Platform. Traders write code in a built-in editor, compile it with one click, and attach it to a chart. From there, the script has full access to the platform:
Read live and historical price data for any symbol on any timeframe.
Draw custom objects on charts — lines, arrows, rectangles, text labels, shapes.
Execute orders, modify positions, and manage stop-loss and take-profit levels.
Store data across sessions using the built-in global variable store.
Read and write files for logging, importing external signals, or exporting results.
Display alerts, send notifications, play sounds.
Hook into platform events — every tick, every new bar, every trade execution, every chart interaction.
417+ Functions, Fully Documented
BSL ships with a standard library covering everything a trading script needs. Mathematical functions, technical indicators, price manipulation, order management, string handling, file input and output, time and date utilities, charting primitives — all built in, all documented, all ready to use.
Whether you are writing a simple moving average crossover or a complex multi-timeframe algorithm with dynamic position sizing, the functions you need are already there.
Designed for Performance
Scripts compile to an optimized internal format and run with minimal overhead. Indicators recalculate only when needed. Robots react to ticks in microseconds, not milliseconds. The engine is built for real-time work, not for educational demos.
We tested it under the same conditions production trading operates in — high-frequency tick feeds, multiple scripts running simultaneously, long trading sessions without memory leaks or slowdowns.
From Simple Scripts to Full Trading Systems
A BSL script can be five lines long — plot a custom line on the chart, and you are done. Or it can be thousands of lines — a full trading system with risk management, multi-symbol correlation, adaptive parameters, and automated journaling.
The same engine runs both. There is no beginner version or advanced version. You start small and grow into it.
Real Examples from Production
Traders using BSL have built:
Custom indicators that combine multiple classical indicators with proprietary logic.
Automated robots that manage entries, exits, and position sizing based on defined rules.
Chart tools that draw complex analytical structures automatically.
Signal scanners that watch dozens of symbols and alert when conditions align.
Backtesting frameworks that validate strategies against historical data before risking real capital.
Every one of these was written by a trader, not by our engineering team. The point of a scripting engine is that the platform becomes a tool the trader shapes to their needs — not a box they operate within.
Open to Learn, Closed to Mistakes
BSL includes clear error messages, a step-through debugger, and comprehensive logging. When your script misbehaves, the engine tells you what went wrong and where—no cryptic runtime errors, no silent failures.
We want traders to learn BSL quickly and use it confidently. The documentation is written for people who want to get productive, not for people who enjoy reading manuals.
The Difference a Real Scripting Engine Makes
A trading platform without scripting is a finished product. A trading platform with scripting is a tool you can extend forever.
BS Trader’s BSL engine gives every trader — retail, institutional, or professional — the ability to build exactly what they need, without waiting for a vendor to add it to the roadmap.
That is the point. That is the value.
Explore the Desktop Platform at bstechnolgy.com and see BSL in action.