Impersonate another user using the Web API

Article
01/01/2023

There are times when your code will need to perform operations on behalf of another user. If the system account running your code has the necessary privileges, you can perform operations on behalf of other users.

Requirements for impersonation

Impersonation is used to execute business logic (code) on behalf of another Microsoft Dataverse user to provide a desired feature or service using the appropriate role and object-based security of that impersonated user. This is necessary because the Dataverse Web services can be called by various clients and services on behalf of a Dataverse user, for example, in a workflow or custom ISV solution. Impersonation involves two different user accounts: one user account (A) is used when executing code to perform some task on behalf of another user (B).

User account (A) needs the prvActOnBehalfOfAnotherUser privilege, which is included in the Delegate security role. The actual set of privileges that is used to modify data is the intersection of the privileges that the Delegate role user possesses with that of the user who is being impersonated. In other words, user (A) is allowed to do something if and only if user (A) and the impersonated user (B) have the privilege necessary for the action.

How to impersonate a user

There are two ways you can impersonate a user, both of which are made possible by passing in a header with the corresponding user id.

Preferred: Impersonate a user based on their Azure Active Directory (AAD) object id by passing that value along with the header CallerObjectId.
Legacy: To impersonate a user based on their systemuserid you can leverage MSCRMCallerID with the corresponding guid value.

In this example, a new account entity is created on behalf of the user with an Azure Active Directory object id e39c5d16-675b-48d1-8e67-667427e9c084.

Request

POST [Organization URI]/api/data/v9.0/accounts HTTP/1.1  
CallerObjectId: e39c5d16-675b-48d1-8e67-667427e9c084  
Accept: application/json  
Content-Type: application/json; charset=utf-8  
OData-MaxVersion: 4.0  
OData-Version: 4.0  
  
{"name":"Sample Account created using impersonation"}

Response

HTTP/1.1 204 No Content  
OData-Version: 4.0  
OData-EntityId: [Organization URI]/api/data/v9.0/accounts(00000000-0000-0000-000000000003)

Determine the actual user

When an operation such as creating an entity is performed using impersonation, the user who actually performed the operation can be found by querying the record including the createdonbehalfby single-valued navigation property. A corresponding modifiedonbehalfby single-valued navigation property is available for operations that update the entity.