App registration

An app registration in Microsoft Entra ID is the registration that represents an application (or service, or integration) in the directory. From an app registration:

• A client ID uniquely identifies the application.
• A client secret or certificate authenticates the application.
• OAuth permissions declare what the application can access — Dataverse user-or-application permissions, Microsoft Graph permissions, etc.
• A service principal is created in the tenant; the app registration's permissions and credentials become the service principal's.
• Redirect URIs for OAuth flows are configured.

For Dynamics 365 integrations, an app registration is the prerequisite for any service-to-service automation — Power Automate flows authenticating to Dataverse, Azure Functions writing to Dataverse, CI/CD pipelines deploying solutions, custom apps consuming Dataverse APIs. Maintain credentials in Azure Key Vault; rotate secrets periodically; audit permissions.