Build a Business Central Extension Fast | AL + GitHub Copilot + VS Code Demo

Build and Publish a Business Central Extension Using AL: Complete Developer Guide

Microsoft Dynamics 365 Business Central is more than just an ERP, it’s a highly extensible platform designed for modern businesses. With the AL programming language and Visual Studio Code, developers can create powerful extensions that tailor Business Central to unique business needs.

In this guide, we walk through a complete end-to-end process of building and publishing a Business Central extension using AL. This includes environment setup, authentication, symbol download, GitHub Copilot-assisted development, and deployment.

🎥 Watch the Full Demo

Why Extend Business Central?

Every business has unique requirements. While Business Central offers strong out-of-the-box capabilities, extensions allow you to:

Customize workflows without modifying core code
Integrate with external systems like eCommerce platforms
Automate repetitive business processes
Enhance reporting and data handling
Build scalable, upgrade-safe solutions

Key Advantage

Extensions are upgrade-safe, meaning Microsoft updates won’t break your customizations.

Business Scenario: Online Marketplace Connector

In this demo, we build a simple extension for an Online Marketplace Connector.

Capture marketplace orders
Convert them into Business Central sales orders
Track order status lifecycle
Manage integration setup

What We Build

Marketplace Order Tables
Order Processing Codeunit
Setup Page
Order List and Card Pages
Status Enum

Step 1: Identify Business Need

We start with a clear requirement: automate marketplace order processing.

Why It Matters

Without this, businesses manually re-enter orders, leading to delays and errors.

Step 2: Prepare Business Central Environment

Open Business Central Admin Center and locate your sandbox environment.

Environment Name: Demyst365
Type: Sandbox
Region: Cloud

Note: Refer to our separate video on creating a sandbox environment in Business Central.

Step 3: AL Language Overview

The AL language is used to develop extensions in Business Central.

Object-based development (Tables, Pages, Codeunits)
Strong integration with Business Central
Supports events and extensibility

Learning Tip

Refer to Microsoft AL Language documentation to master development concepts.

Step 4: Install AL Language Extension

In Visual Studio Code:

Go to Extensions
Search: AL Language
Install Microsoft AL extension

Step 5: Create Project Using AL:Go!

Open Command Palette:

Press Ctrl + Shift + P
Select AL: Go!

This initializes your project.

Step 6: Select Environment

Choose:

Microsoft Cloud Sandbox
Select your environment: Demyst365

Step 7: Authentication

Why This Step Matters

This connects VS Code to your Business Central environment securely.

Step 8: Download Symbols

Symbols represent Business Central objects.

Download happens automatically
Stored in .alpackages folder

Importance

Without symbols, your extension cannot reference standard BC objects.

Step 9: Review Project Structure

Your project includes:

app.json
launch.json
src folder
.alpackages

Step 10: Configure app.json

Update:

Name
Publisher
Version
ID

Best Practice

Use unique IDs to avoid conflicts.

Step 11: Configure launch.json

Important settings:

environmentType: Sandbox
environmentName: Demyst365
startupObjectId: 50100

What is startupObjectId?

This defines which page opens after publishing. In this demo, it opens the Setup Page.

Step 12: Define Business Objects

Create:

Enum for order status
Tables for orders and lines
Pages for UI
Codeunit for processing

Structure Example

Table: Marketplace Order Header
Page: Marketplace Orders
Codeunit: Marketplace Management

Step 13: Use GitHub Copilot

Instead of writing everything manually:

Write prompt describing business logic
Let Copilot generate AL code

Example Prompt

Create a codeunit to convert marketplace orders into Business Central sales orders.

Step 14: Debugging and Error Handling

Use:

F5 → Run with Debugging
Breakpoints
Error messages

Example

If Customer No. is missing, show validation error.

Step 15: Publish Extension

Press F5:

Builds extension
Publishes to sandbox
Opens Business Central

Step 16: Validate in Business Central

Search:

OMO Setup
Marketplace Orders

Test functionality.

Business Value

Eliminates manual work
Improves accuracy
Enables automation
Scales operations

How INFOC Helps

At INFOC, we help organizations:

Design scalable extensions
Implement integrations
Enable EPM and BPM solutions
Optimize Business Central performance

Final Thought

With the right tools and approach, Business Central becomes a powerful platform for innovation, not just operations.