Getting Started with AL

To get started writing extensions for Dynamics 365 Business Central you will need a Dynamics 365 Business Central tenant, Visual Studio Code, and the AL Language extension. Visual Studio Code is a cross platform editor that you will use for coding and debugging.

Steps to set up a sandbox environment and Visual Studio Code

Go through the following steps to set up a sandbox environment. With this you get sample code that compiles and runs with just a few commands.


If you want to create a container-based sandbox, see Get started with the Container Sandbox Development Environment. For information about which sandboxes you can choose, see Choosing Your Dynamics 365 Business Central Development Sandbox Environment.

  1. Sign up for a Dynamics 365 Business Central sandbox.
  2. Download Visual Studio Code.
  3. Download the AL Language extension.
  4. Press Ctrl+, to open the user settings window; here you can modify the telemetry settings.
  5. Press Alt+A, Alt+L to trigger the AL Go! command, and then choose Microsoft cloud sandbox.


    If you want to change your configuration at a later point in time, choose Add Configuration on the right side, and then choose one of the available options.

  6. Enter the credentials you provided for the signup, and then symbols will automatically start downloading. To manually download the symbols, press Ctrl+Shift+P and select AL: Download symbols.
  7. Press F5 to deploy and run the extension on your online sandbox tenant.

You now have a HelloWorld sample that compiles and runs. The JSON files in the project are automatically updated with the settings that allows you to press F5 to build and deploy the solution.

Tips and tricks

  • Use Ctrl+Space to activate IntelliSense.
  • Always use the .al extension on new files.
  • Use the built-in snippets for code by starting typing t and pick from the list.
  • Create objects within the right object ranges, see Object Ranges in Dynamics 365 Business Central.
  • Build and get inspired by our sample library on GitHub.
  • Use Ctrl+Shift+P to clear the credentials cache if you want to deploy against a different environment.

JSON file settings

There are two JSON files in the project; the app.json file and the launch.json file. The files are automatically generated for your project. For more information, see JSON files.

Telemetry settings

By default, Visual Studio Code is set up with a telemetry system to enable that data and errors are sent to Microsoft. If you do not want to send telemetry data, you can change the telemetry.enableTelemetry setting from true to false.

To modify the telemetry setting, press Ctrl+, in Visual Studio Code and choose the user settings window, which opens the settings.json file, and then add telemetry.enableTelemetry and set it to false.

"telemetry.enableTelemetry": false,


The settings.json file contains user and workspace settings, these options can be modified to suit your preference. If you want to modify Visual Studio Code editor options and functional behavior settings, see User and Workspace Settings.

The symbol file

The symbol file contains metadata of the application. This is what your extension is being built on, and therefore the symbol file must be present. If it is not present, you will be prompted to download it. For more information about the platform symbol file, see Symbols.

Installing and publishing an extension

To make your extension available to users, the package must be published to a specific Microsoft Dynamics 365 Business Central Server instance. The extension can be installed for one or more tenants. For more information about how to install and publish an extension, see How to: Publish and Install an Extension.

Controlling user access to publishing extensions

The access to publishing extensions is controlled on a user or user group basis by the D365 EXTENSION MGT permission set.


If you add new permission sets and want to control the access to developing and publishing extensions, you must include indirect read and write permissions to the NavApp table (read – for downloading symbols, write – for publishing the app) in the permission set.

To prohibit a user from publishing, just remove the user from the D365 EXTENSION MGT permission set.

Next steps

Now that you have the tools and the HelloWorld example up and running, you might want to try to create a small sample app in AL. This walkthrough guides you through how to create a simple app adding objects, code, and publishing the app to your tenant. For more information, see Building Your First Sample Extension With Extension Objects, Install Code, and Upgrade Code.

See Also

AL Development Environment
FAQ for Developing in AL
Building Your First Sample Extension With Extension Objects, Install Code, and Upgrade Code