Use Multi-Tenant Server-to-server authentication

This is the most common scenario and the one which is used for apps distributed using Microsoft AppSource, but you can also use multi-tenant without listing your application with Microsoft AppSource.

Each Common Data Service organization is associated with an Azure Active Directory tenant. Your web application or service is registered with its own Azure AD tenant.

In this scenario any Common Data Service tenant can potentially use your multi-tenant application after they grant consent for the application to access data.


To create and test a multi-tenant application that uses server-to-server (S2S) authentication you will need:

  • An Azure AD tenant you will use to publish your application or service.

  • 2 Common Data Service subscriptions

    • One must be associated with Azure AD tenant you will use to publish your application or service.

    • The other might be a trial subscription to use for testing how a subscriber will access your application.

Overview: Develop and test your application

The application you will create must be registered with the Azure AD tenant you will use when you publish the application.

At a high level, the process consists of:

  1. Create a multi-tenant web application registered with your Azure AD tenant.

  2. Create an application user associated with the registered application in your Common Data Service tenant

  3. Create a custom security role and assign it to the application user in your Common Data Service tenant

  4. Test your application using your Common Data Service tenant

  5. Test your application using a separate Common Data Service tenant

Create a multi-tenant web application registered with your Azure AD tenant

You will create a multi-tenant web application or service which uses Azure AD as the authentication provider.

Exactly how you do this will not be the focus of this topic. There are a number of ways you can approach this and make choices that fit your requirements or preferences. See the following links for more information and samples:

Value Description
Application ID URI The identifier for an application. This value is sent to Azure AD during authentication to indicate which application the caller wants a token for. Additionally, this value is included in the token so that the application knows it was the intended target.
Reply URL and Redirect URI In the case of a web API or web application, the Reply URL is the location to which Azure AD will send the authentication response, including a token if authentication was successful.
Client ID The ID for an application, which is generated by Azure AD when the application is registered. When requesting an authorization code or token, the client ID and key are sent to Azure AD during authentication.
Key The key that is sent along with a client ID when authenticating to Azure AD to call a web API .

When the application is registered it will be assigned an Azure Active Directory Object Id, a unique identifier for the registered application.

If you create a new ASP.NET MVC application with Visual Studio you will have options to specify that the application will support the multi-tenant functionality. The template for an MVC application provides the option to specify what kind of authentication occurs. You will have the option to choose the authentication method by configuring the properties of your project when you create it. The following diagram shows the options available:

ASP.NET  MVC Change Authentication Dialog

When you configure a project with these options it will be configured to use OWIN middleware and scaffolding for a basic application that supports this scenario. With some basic modifications it can be adapted to work with Common Data Service.

In the process of creating and registering your application for development you will most likely use https://localhost as the Sign-on URL and Reply URL values so you can test and debug your application locally before publishing. You will need to change these values before you publish your app.

When you register your app you must generate a key, also known as a ClientSecret. These keys can be configured for a 1 or 2-year duration. As the host of the application you must treat this value like a password and it is your responsibility to manage renewal of the keys before they expire. You may want to use Key Vault. More information:

Grant your application rights to access Common Data Service data

This is the reason why your Common Data Service instance must be associated with your Azure AD tenant. If your Azure AD tenant is not associated with a Common Data Service tenant, you will not be able to perform the following steps.

  1. Go to and select Azure Active Directory.

  2. Click App registrations and look for the application you created using Visual Studio.

  3. You need to give your application privileges to access Common Data Service data. In the API Access area click Required permissions. You should see that it already has permissions for Windows Azure Active Directory.

  4. Click Add, then Select an API. In the list, select Dynamics 365 and then click the Select button.

  5. In Select permissions, select Access Dynamics 365 as organization users. Then click the Select button.

  6. Click Done to add these permissions. When you are done you should see the permissions applied.

    Grant Dynamics 365-Permissions to application

Create an application user associated with the registered application in Common Data Service

When your application accesses the Common Data Service data of one of the subscribers of your application, it will require an application user in the subscriber’s Common Data Service organization. Like any Common Data Service user, this application user must be associated with at least one security role which defines the data the user is able to access.

The SystemUser Entity has three new attributes to store this data.

Schema Name Display Name Type Description
ApplicationId Application ID UniqueidentifierType The identifier for the application. This is used to access data in another application.
ApplicationIdUri Application ID URI StringType The URI used as a unique logical identifier for the external app. This can be used to validate the application
AzureActiveDirectoryObjectId Azure AD Object ID UniqueidentifierType This is the application directory object Id.

This systemuser``AzureActiveDirectoryObjectId property value must be a reference to the Azure Active Directory Object Id of your registered application. This reference will be set in Common Data Service when the application user is created based on the ApplicationId value.


When you are initially developing your application with your own Common Data Service tenant and the Azure AD tenant associated with it, you can simply create the application user because the registered application is already part of your Azure AD tenant.

However, in order to create the application user in a different organization for testing, or whenever a subscriber will use your application, they must first grant consent for your application, so the steps in the process are different. See Test your application using a separate Dynamics 365 tenant for more information.

Create a security role for the application user

In the next step you will create a Common Data Service application user. The privileges and access rights for this user will be defined by a custom security role you set. Before you create the application user, you must create a custom security role so you can associate the user to it. More information: Create or edit a security role


The application user cannot be associated with one of the default Common Data Service security roles. You must create a custom security role to associate with the application user.

Manually create a Common Data Service application user

The procedure to create this user is different from creating a licensed user. Use the following steps:

  1. Navigate to Settings > Security > Users

  2. In the view drop-down, select Application Users.

  3. Click New. Then verify that you are using the Application user form.

    If you do not see the Application ID, Application ID URI and Azure AD Object ID fields in the form, you must select the Application User form from the list:

    Select Application User Form

  4. Add the appropriate values to the fields:

    Field Value
    Application ID The Application ID value for the application registered with Azure AD.
    Full Name The name of your application.
    Primary Email The email address you want your subscribers to use to contact you.

    The User Name, Application ID URI and Azure AD Object ID fields are locked and you cannot set values for these fields.

    When you create this user the values for these fields will be retrieved from Azure AD based on the Application ID value when you save the user.

  5. Associate the application user with the custom security role you created in Create a security role for the application user. More information: Create users and assign security roles

Test your application using your Common Data Service tenant

Because the application has been registered with your Azure AD tenant and the application user in your development organization is already configured, you can continue to develop your application against your own Common Data Service tenant. But this is not a valid test of the multi-tenant capability. You need to test your application on a separate Common Data Service tenant.

Test your application using a separate Common Data Service tenant

Before you test your application with a separate Common Data Service tenant, an administrator for the Azure AD tenant must grant consent for the application. The administrator grants consent by navigating to the application using a browser. The first time they access the application, they will see a dialog like this:

Grant consent to access Dynamics 365 data

When they grant consent, your registered application will be added to the Azure AD Enterprise applications list and it is available to the users of the Azure AD tenant.

Only after an administrator has granted consent, you must then create the application user in the subscriber’s Common Data Service tenant. You can manually create the application user using the steps described in Manually create a Dynamics 365 application user.

For initial tests you may want to manually perform these steps. When you are ready to make your application or service available to subscribers you will want to have a more efficient procedure. This is covered in the next section.

Prepare a method to deploy the application user

After subscribers grant consent to your application or service you will need an easy, reliable way for them to add the application user and any other required components to their Common Data Service organization.

You must include a custom security role which defines what privileges your application requires and then make sure that the application user is associated to that custom security role. Because a custom security role can be included in a solution, you should prepare a managed solution which contains the definition of the custom security role and any other solution components your application requires.

For information about creating custom security roles, see

See also

Use Single-Tenant Server-to-server authentication
Build web applications using Server-to-Server (S2S) authentication
Connect to Dynamics 365