atdl4j is an open source and not-for-profit JavaTM implementation of FIXatdlSM, the FIX ProtocolSM Algorithmic Trading Definition Language standard developed by FIX Protocol Limited (FPL).

atdl4j is a collaboration between Buy-side and Sell-side innovators within the Electronic Trading industry, and is integrated within the trading systems of several major investment banks and FIX providers. The atdl4j project is intended to promote open source standards within finance, and to increase the adoption rate of the FIXatdl standard itself.

While the atdl4j open source effort encourages the use of and implementation of the FIXatdl standard, it is an independent effort and not directly affiliated with the FIX Protocol Limited organization.


  • Displays algo input screens based on the latest industry-standard FIXatdl 1.1 XML schema
  • Reads and generates algorithm-specific FIX message content
  • Can be integrated into a trading system, or run as a standalone testing/validation tool.
  • Supports the full set of UI widgets defined in FIXatdl 1.1
  • Support for message validation and widget state rules (such as show/hide and enable/disable.)
  • Supports strategy filtering, customizable settings, and context-specific views (for example Cancel/Replace mode)
  • Written in the Java language using standard libraries. Both Swing and SWT user interfaces available.
  • Source code can be modified to support in-house FIXatdl schema extensions


atdl4j is licensed under the MIT License. The MIT License permits reuse within proprietary software on the condition that the license is distributed with that software, making it ideal for use within the legal guidelines of most financial firms. Please consult the Legal and Compliance department at your firm before adopting atdl4j or other open source software.

Key Contributors


We kindly ask that those who do get value from the atdl4j platform contribute back to the community. If you wish to contribute code to atdl4j, please fork the atdl4j project on GitHub.

Looking for a .NET implementation of FIXatdl? Check out atdl4net