Design for extensibility


Some of the functionality described in these release notes has not been released. Delivery timelines may change and projected functionality may not be released (see Microsoft policy). Learn more: What's new and planned

Enabled for Public preview General availability
Admins, makers, or analysts, automatically October 2019

Feature details

The first release of the source code for the Microsoft application in AL is a new era where all applications are extensions, and extensibility begins to replace code customization. To facilitate this change, we’re working to make the core application thinner, more extensible, and easier to localize by extracting more and more of our system logic into modules, forming a system application and an application foundation.

These modules are putting simplicity in focus by following a one feature = one module principle. Each module encapsulates the complexity and replaces implementation details with clean, documented, and stable APIs.

The smaller modules speed up the development cycle, and make it easier to monitor and optimize functionality from security and performance perspectives. The number of modules can vary, depending on the configuration, and you can update each module individually.

Because this is a major shift in the development paradigm for both Microsoft and our partner community, we make each module available well ahead of the 2019 release wave 2. As we finish modules, we publish the source code in the ALAppExtensions repo on GitHub so that you can provide direct feedback and make contributions.

Tell us what you think

Help us improve Dynamics 365 Business Central by discussing ideas, providing suggestions, and giving feedback. Use the forum at