PnP Core SDK - Azure Function with Managed Identity Sample

Important

Beginning 10 November 2026, the in-process model for .NET apps in Azure Functions will no longer be supported. To ensure that your apps that use this model continue being supported, you'll need to transition to the isolated worker model by that date. Retirement: Support for the in-process model for .NET apps in Azure Functions ends 10 November 2026. This sample is a new version of the Azure V4 Function using managed identity (in-process) using in-process model.

This solution demonstrates how to build Azure function that connects to a SPO site using:

  • System-Managed Identity, when running in Azure and
  • Azure Ad application (App Registration) during local development.

The Authentication Provider is selected based on the presence of the MSI_SECRET token, which is only available if Managed Identity is enabled.

When the function is executed in Azure, it uses custom ManagedIdentityTokenProvider authentication provider, which invokes Azure.Identity.ManagedIdentityCredential class to attempt authentication using a managed identity that has been assigned to the Azure Function.

For local development, certificate-based authentication with X509CertificateAuthenticationProvider is required.

App-only authentication against SharePoint Online requires certificate based authentication for calling the "classic" SharePoint REST/CSOM APIs. The SharePoint Graph calls can work with clientid+secret, but since PnP Core SDK requires both type of APIs (as not all features are exposed via the Graph APIs) you need to use certificate based auth.

This solution follows the principle of least privilege, by using Sites.Selected application permissions for Graph and SharePoint APIs, and Read/Write/FullControl permissions granted to a specific SPO site.

Always choose minimum required permissions.

Source code

Note

This sample was authored by Kinga Kazala 💪🥇.

You can find the sample source code here: /samples/Demo.AzFunction.ManagedIdentityV2

Note

This sample was created with Visual Studio Code using .NET 8.0 and has been created as an Azure Function v4 running in the isolated worker model.

Sample configuration

Note

For the sample setup, you will need to have a recent version of PnP.PowerShell installed on your machine.

Create and configure the Azure AD applications

The Azure Function must have System-Managed Identity enabled. Before you execute the next steps, make sure you enable System-Managed Identity.

The configuration script:

  • Creates a new App Registration with a name {$appName}-LocalDev and generates a new self-signed certificate
  • Grants Sites.Selected API Permissions to the {$appName} Managed Identity and the {$appName}-LocalDev Azure AD application
  • Grants permissions defined in Permissions parameter to the {$appName} Managed Identity and the {$appName}-LocalDev Azure AD application
  • saves the site and tenant information, client id and the certificate thumbprint to the local.settings.json configuration file.
{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet",
    "SiteUrl": "",
    "TenantId": "[TENANT ID]",
    "ClientId": "[CLIENT ID]",
    "CertificateThumbPrint": "[CERTIFICATE THUMBPRINT]",
    "WEBSITE_LOAD_CERTIFICATES": "[CERTIFICATE THUMBPRINT]"
  }
}
Important

Currently, you cannot manually grant API Permissions to the System-Managed Identity

Execute the Configure.ps1, defining the Permissions level that your application requires.

This sample requires FullControl permissions because it creates a new list.

Note

You may decide to only grant Write permissions to see the REST errors once the code reaches method requiring FullControl permissions.

access denied

.\Configure.ps1 -SiteUrl $siteUrl -TenantId $tenantId -AzureADAppName $appName -Permissions FullControl -CertificatePwd ""
Important
  • To consent to the application permissions, make sure you are an Azure AD admin or a global admin in your tenant

Run the sample locally

Note

Before you get started, make sure to configure your environment.

To test your code locally, follow the Run the function locally procedure.

Observe the output printed to the Terminal. It will confirm you are running your code locally ("Local DEV using cert auth"), authenticate to the SharePoint site and attempt to execute functions requiring Read, Write and FullControl permissions.

In case you only granted Write permissions to the app, you will see an error message when the function attempts to create a new list.

terminal output error

If you granted FullControl permissions, all the steps will be completed successfully.

terminal output success

Deploy the sample to Azure

Create Azure Function App

Go to the Azure Portal and create a new Function App (consumption plan) using following settings:

  • Runtime stack: .NET
  • Version: 8 (LTS), isolated worked model
  • Region: pick the region that works best for you
  • Operating System: Windows

Note: This sample has only been tested with the above configuration.

Click Review + create, verify the settings and click Create. Now your function is provisioned in Azure.

Configure the Function App

Once the Function App has been created navigate to Settings -> Configuration and add the following Application setting:

Name Value
SiteUrl the Url of your SPO site, e.g. https://contoso.sharepoint.com/sites/subsiteName

Click Save to persist the changes.

Note

You don't need TenantId, ClientId, CertificateThumbPrint or WEBSITE_LOAD_CERTIFICATES application settings when using Managed Identity authentication.

Under Function runtime settings verify the Runtime version is set to ~4.

Deploy the Function App code from Visual Studio

To deploy the project to Azure:

Test your Function App in Azure

Test the function in Azure using the run the function in Azure procedure.

Performance optimizations

See Performance optimizations for changes you can implement to improve performance of your Azure Function.