Register a public client application in Microsoft Entra ID for Azure API for FHIR


Azure API for FHIR will be retired on September 30, 2026. Follow the migration strategies to transition to Azure Health Data Services FHIR service by that date. Due to the retirement of Azure API for FHIR, new deployments won't be allowed beginning April 1, 2025. Azure Health Data Services FHIR service is the evolved version of Azure API for FHIR that enables customers to manage FHIR, DICOM, and MedTech services with integrations into other Azure services.

In this article, you'll learn how to register a public application in Microsoft Entra ID.

Client application registrations are Microsoft Entra representations of applications that can authenticate and ask for API permissions on behalf of a user. Public clients are applications such as mobile applications and single page JavaScript applications that can't keep secrets confidential. The procedure is similar to registering a confidential client, but since public clients can't be trusted to hold an application secret, there's no need to add one.

The quickstart provides general information about how to register an application with the Microsoft identity platform.

App registrations in Azure portal

  1. In the Azure portal, on the left navigation panel, select Microsoft Entra ID.

  2. In the Microsoft Entra ID blade, select App registrations:

    Azure portal. New App Registration.

  3. Select New registration.

Application registration overview

  1. Give the application a display name.

  2. Provide a reply URL. The reply URL is where authentication codes will be returned to the client application. You can add more reply URLs and edit existing ones later.

    Azure portal. New public App Registration.

To configure your desktop, mobile or single-page application as public application:

  1. In the Azure portal, in App registrations, select your app, and then select Authentication.

  2. Select Advanced settings > Default client type. For Treat application as a public client, select Yes.

  3. For a single-page application, select Access tokens and ID tokens to enable implicit flow.

    • If your application signs in users, select ID tokens.
    • If your application also needs to call a protected web API, select Access tokens.

API permissions

Permissions for Azure API for FHIR are managed through RBAC. For more details, visit Configure Azure RBAC for FHIR.


Use grant_type of client_credentials when trying to otain an access token for Azure API for FHIR using tools such as Postman. For more details, visit Testing the FHIR API on Azure API for FHIR.

Validate FHIR server authority

If the application you registered in this article and your FHIR server are in the same Microsoft Entra tenant, you're good to proceed to the next steps.

If you configure your client application in a different Microsoft Entra tenant from your FHIR server, you'll need to update the Authority. In Azure API for FHIR, you do set the Authority under Settings --> Authentication. Set your Authority to ``<TENANT-ID>`.

Next steps

In this article, you've learned how to register a public client application in Microsoft Entra ID. Next, test access to your FHIR Server using Postman.

FHIR® is a registered trademark of HL7 and is used with the permission of HL7.