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Exam Information
Official specifications published by Microsoft
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Skills this practice test covers
- Create an AL extension in Visual Studio Code and manage its app.json and launch.json files.
- Build and extend tables, pages, enums and Role Center pages.
- Design a report's data model and layouts, and substitute a standard report.
- Write codeunits that use events and interfaces, plus install and upgrade codeunits.
- Create custom telemetry signals and test codeunits for an extension.
- Publish API pages and OData bound and unbound actions, and call REST services with the HTTP classes.
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MB-820 exam content
6 domains · 22 topics · 69 of 73 questions sorted by domain
Describe Business Central6 questions
This domain sets the context for development. Candidates describe the components of Business Central, the core solution and extensions approach, the update lifecycle for customizations and the online and on-premises differences. They also separate the base app from the system app.
Skills tested
- Explain why customizations are built as extensions instead of changes to the core solution.
- Describe the update lifecycle for customizations of Business Central.
- Differentiate Business Central online and on-premises features.
- Describe the process of bringing an app to AppSource.
Questions by topic
- Differentiate Business Central online and Business Central on-premises features3
- Differentiate between the base app and the system app3
Install, develop, and deploy for Business Central4 questions
Here the candidate sets up the tools and ships the code. That means installing the development environment, managing configuration files and multi-extension workspaces, and creating, debugging, deploying and maintaining extensions in Visual Studio Code.
Skills tested
- Install and configure Visual Studio Code with the AL Language extension.
- Manage the app.json and launch.json files of an AL extension.
- Work with several AL extensions in one workspace.
- Debug, deploy and maintain an extension, including multilanguage development.
Questions by topic
- Manage multiple AL extensions in one workspace3
- Manage configuration files for an AL extension1
Develop by using AL objects24 questions
The largest domain covers the objects an extension is built from. Candidates build and extend tables, pages, enums, reports and XMLports, and write codeunits, queries, entitlements and permission sets.
Skills tested
- Develop Role Center pages and choose the right page type for a task.
- Substitute a report, design its data model and create report layouts.
- Configure XMLport properties and nodes, and use XMLports in AL code.
- Use events, triggers and interfaces, and create install and upgrade codeunits.
- Override entitlements with inherent permissions and troubleshoot permission sets.
Questions by topic
- Create queries in Business Central3
- Use a query to create a report3
- Build and extend tables4
- Create installation and upgrade codeunits3
- Design and create an XMLport3
- Create a report layout4
- Use events and triggers3
- Implement interfaces1
Develop by using AL15 questions
This domain is about the language and the user experience. Candidates use AL data types, expressions, built-in functions, error handling and access modifiers, follow the essential development standards, and onboard users with profiles, views, assisted setup and teaching tips.
Skills tested
- Create profiles and views in AL.
- Add assisted setup, teaching tips, in-app tours and an onboarding checklist.
- Apply the data process model and the document and master data standards.
- Use access modifiers to limit access, and manage errors in AL code.
Questions by topic
- Integrate assisted setup4
- Use access modifiers to limit access4
- Customize the UI experience3
- Describe the essential development standards4
Work with development tools11 questions
This domain covers testing and telemetry. Candidates install and run the Test Toolkit, write test codeunits and procedures, and configure, monitor and extend telemetry with custom signals.
Skills tested
- Install and run the Test Toolkit and the standard Business Central tests.
- Develop test codeunits and test procedures.
- Configure telemetry, analyze it and create custom telemetry signals.
Questions by topic
- Configure telemetry4
- Develop test codeunits and procedures3
- Monitor and analyze telemetry4
Integrate Business Central with other applications9 questions
This domain connects Business Central with other systems in both directions. Candidates call external REST services with the HTTP classes and JSON, and publish APIs with OData bound and unbound actions and Read Scale-Out.
Skills tested
- Get data from and send data to an external REST service with the HTTP classes.
- Read and write JSON in AL.
- Create API pages and OData bound and unbound actions.
- Use Read Scale-Out to run read-only work against a database replica.
Questions by topic
- Access Representational State Transfer (REST) services from within Business Central3
- Create and manage OData bound and unbound actions3
- Use Read Scale-Out to improve performance3
Requirements
- No formal prerequisites: anyone can book the exam.
- Recommended: applied knowledge of Business Central and of AL, the development environment and its tools.
- Recommended: some knowledge of how to install and upgrade Business Central.
- Recommended: knowledge of AppSource and of application lifecycle management, including source control and CI/CD.
About the MB-820 exam
MB-820 checks whether a developer can design, build, test and maintain apps that extend Dynamics 365 Business Central. The code is written in the application language (AL) with Visual Studio Code. The domains run from the architecture and the development environment to AL objects, the AL language, testing, telemetry and integration. Developers must also keep data current during an upgrade, which is the job of upgrade codeunits. Passing earns the Microsoft Certified: Dynamics 365 Business Central Developer Associate certification.
Develop by using AL objects has the most questions in the PlanetCert practice test, spread across tables, report layouts, XMLports, queries and codeunits. Every question has an explanation, which helps where two options differ in one detail, such as an OData bound action and an unbound action. Study Mode suits the telemetry and testing questions. Brainy AI Assistant can read an AL snippet and explain what it does, or say when Read Scale-Out applies.
How to earn the certification
- Earns
- Microsoft Certified: Dynamics 365 Business Central Developer AssociateAssociate
The certification expires each year. Holders renew it with a free online assessment on Microsoft Learn.
How to prepare for MB-820
- 1
Install the AL toolchain
Install Visual Studio Code and the AL Language extension, then connect to a Business Central sandbox. Create a new extension and read every setting in its app.json and launch.json files.
- 2
Build a small app from scratch
Add a new table with a list page and a card page, an enum, and a codeunit that subscribes to a posting event. Then publish it, debug it, and add a second language for its captions.
- 3
Spend the most time on AL objects
Develop by using AL objects is the largest domain. Build a report with two layouts, an XMLport for a CSV import, a query with totals, and a permission set for the new objects.
- 4
Call a REST service, publish an API
Use the HTTP classes and the JSON types to read data from an external REST service. Then publish an API page and an unbound action, and call both from a REST client.
- 5
Test, instrument, then practise
Write a test codeunit, run it with the Test Toolkit, and send a custom telemetry signal to Application Insights. Then take the MB-820 practice test in Study Mode and a full run in Timed Mode. Ask Brainy AI Assistant about any AL question that was missed.
Start a timed MB-820run
Microsoft's instructor-led course for this exam is MB-820T00-A: Dynamics 365 Business Central Developer. Its learning paths include Build reports for Microsoft Dynamics 365 Business Central and Interface with Microsoft Dynamics 365 Business Central.
Who MB-820 is for
- Developers who write AL extensions or AppSource apps for Business Central customers.
- Technical consultants who integrate Business Central with Power Platform, REST services and other systems.
- Software engineers who test, upgrade and maintain Business Central solutions.
Typical job titles: Business Central developer · AL developer · Dynamics 365 developer · ERP developer · Technical consultant
MB-820 glossary
20 terms from the exam objectives and the vendor's official material, each defined in a sentence.
- app.json
- The manifest file of an AL extension, which sets its ID, name, version, dependencies and other settings.
- Application Insights
- The Azure service that receives Business Central telemetry, where developers query and analyze it.
- Application language (AL)
- The programming language used to write Business Central extensions, edited in Visual Studio Code.
- AppSource
- Microsoft's marketplace where partners publish Business Central apps after Microsoft validates them.
- Base app
- The Base Application from Microsoft. It holds Business Central's business logic for areas such as sales, purchasing and the general ledger.
- Bound actions
- OData actions tied to an entity that a page exposes, so a client can run a procedure on one record.
- Entitlement
- An AL object that sets which objects a license or plan lets users reach.
- Enum
- A named list of values in AL. Other extensions can add values to it when the enum is extensible.
- Event subscribers
- Procedures that run when a published event fires, so an extension can add logic without changing the publisher's code.
- Extension
- An AL app that adds features to Business Central or changes them while the base application stays untouched.
- Inherent permissions
- Permissions given to an object in code, so it can work with certain data whatever the user's own permissions.
- Interface
- An AL object that declares procedures, which several codeunits can implement in their own way.
- launch.json
- The Visual Studio Code file that tells the AL tools which Business Central server or sandbox to publish to and debug against.
- Read Scale-Out
- A feature that runs read-only work, such as reports and API reads, against a read-only replica of the database.
- Role Center
- A user's home page in Business Central, built from cues, actions and parts that suit one role.
- System app
- The System Application from Microsoft: a layer of technical modules that other apps build on.
- Teaching tips
- Short pop-up notes on a page that explain what the page is for, used to onboard new users.
- Test Toolkit
- Microsoft's test libraries and standard tests for Business Central, with the tools to run them.
- Upgrade codeunits
- Codeunits that run when a new version of an extension is installed, to move or update the old version's data.
- XMLport
- An AL object that imports or exports data as XML or as text files.