Build Python apps with Microsoft Graph and app-only authentication

2025-06-11

This tutorial teaches you how to build a Python console app that uses the Microsoft Graph API to access data using app-only authentication. App-only authentication is a good choice for background services or applications that need to access data for all users in an organization.

Note

To learn how to use Microsoft Graph to access data on behalf of a user, see this user (delegated) authentication tutorial.

In this tutorial, you will:

List users

Tip

As an alternative to following this tutorial, you can download or clone the GitHub repository and follow the instructions in the README to register an application and configure the project.

Prerequisites

Before you start this tutorial, you should have Python and pip installed on your development machine.

You should also have a Microsoft work or school account with the Global administrator role. If you don't have a Microsoft 365 tenant, you might qualify for one through the Microsoft 365 Developer Program; for details, see the FAQ. Alternatively, you can sign up for a one-month free trial or purchase a Microsoft 365 plan.

Note

This tutorial was written with Python version 3.10.4 and pip version 20.0.2. The steps in this guide might work with other versions, but that hasn't been tested.

Register application for app-only authentication

Microsoft Entra admin center
PowerShell

Open a browser and navigate to the Microsoft Entra admin center and sign in using a Global administrator account.
Select Microsoft Entra ID in the left-hand navigation, expand Identity, expand Applications, then select App registrations.
Select New registration. Enter a name for your application, for example, Graph App-Only Auth Tutorial.
Set Supported account types to Accounts in this organizational directory only.
Leave Redirect URI empty.
Select Register. On the application's Overview page, copy the value of the Application (client) ID and Directory (tenant) ID and save them. You'll need these values in the next step.
Select API permissions under Manage.
Remove the default User.Read permission under Configured permissions by selecting the ellipses (...) in its row and selecting Remove permission.
Select Add a permission, then Microsoft Graph.
Select Application permissions.
Select User.Read.All, then select Add permissions.
Select Grant admin consent for..., then select Yes to provide admin consent for the selected permission.
Select Certificates and secrets under Manage, then select New client secret.
Enter a description, choose a duration, and select Add.
Copy the secret from the Value column, you'll need it in the next steps.

Important

This client secret is never shown again, so make sure you copy it now.

To use PowerShell, you need the Microsoft Graph PowerShell SDK. If you don't have it, see Install the Microsoft Graph PowerShell SDK for installation instructions.

Create a new file named RegisterAppForAppOnlyAuth.ps1 and add the following code.

param(
  [Parameter(Mandatory=$true,
  HelpMessage="The friendly name of the app registration")]
  [String]
  $AppName,

  [Parameter(Mandatory=$true,
  HelpMessage="The application permission scopes to configure on the app registration")]
  [String[]]
  $GraphScopes,

  [Parameter(Mandatory=$false)]
  [Switch]
  $StayConnected = $false
)

$graphAppId = "00000003-0000-0000-c000-000000000000"

# Requires an admin
Connect-MgGraph -Scopes "Application.ReadWrite.All AppRoleAssignment.ReadWrite.All User.Read" -UseDeviceAuthentication -ErrorAction Stop

# Get context for access to tenant ID
$context = Get-MgContext -ErrorAction Stop
$authTenant = $context.TenantId

# Create app registration
$appRegistration = New-MgApplication -DisplayName $AppName -SignInAudience "AzureADMyOrg" -ErrorAction Stop
Write-Host -ForegroundColor Cyan "App registration created with app ID" $appRegistration.AppId

# Create corresponding service principal
$appServicePrincipal = New-MgServicePrincipal -AppId $appRegistration.AppId -ErrorAction SilentlyContinue `
  -ErrorVariable SPError
if ($SPError)
{
  Write-Host -ForegroundColor Red "A service principal for the app could not be created."
  Write-Host -ForegroundColor Red $SPError
  Exit
}

Write-Host -ForegroundColor Cyan "Service principal created"

# Lookup available Graph application permissions
$graphServicePrincipal = Get-MgServicePrincipal -Filter ("appId eq '" + $graphAppId + "'") -ErrorAction Stop
$graphAppPermissions = $graphServicePrincipal.AppRoles

$resourceAccess = @()

foreach($scope in $GraphScopes)
{
  $permission = $graphAppPermissions | Where-Object { $_.Value -eq $scope }
  if ($permission)
  {
    $resourceAccess += @{ Id =  $permission.Id; Type = "Role"}
  }
  else
  {
    Write-Host -ForegroundColor Red "Invalid scope:" $scope
    Exit
  }
}

# Add the permissions to required resource access
Update-MgApplication -ApplicationId $appRegistration.Id -RequiredResourceAccess `
 @{ ResourceAppId = $graphAppId; ResourceAccess = $resourceAccess } -ErrorAction Stop
Write-Host -ForegroundColor Cyan "Added application permissions to app registration"

# Add admin consent
foreach ($appRole in $resourceAccess)
{
  New-MgServicePrincipalAppRoleAssignment -ServicePrincipalId $appServicePrincipal.Id `
   -PrincipalId $appServicePrincipal.Id -ResourceId $graphServicePrincipal.Id `
   -AppRoleId $appRole.Id -ErrorAction SilentlyContinue -ErrorVariable SPError | Out-Null
  if ($SPError)
  {
    Write-Host -ForegroundColor Red "Admin consent for one of the requested scopes could not be added."
    Write-Host -ForegroundColor Red $SPError
    Exit
  }
}
Write-Host -ForegroundColor Cyan "Added admin consent"

# Add a client secret
$clientSecret = Add-MgApplicationPassword -ApplicationId $appRegistration.Id -PasswordCredential `
 @{ DisplayName = "Added by PowerShell" } -ErrorAction Stop

Write-Host
Write-Host -ForegroundColor Green "SUCCESS"
Write-Host -ForegroundColor Cyan -NoNewline "Client ID: "
Write-Host -ForegroundColor Yellow $appRegistration.AppId
Write-Host -ForegroundColor Cyan -NoNewline "Tenant ID: "
Write-Host -ForegroundColor Yellow $authTenant
Write-Host -ForegroundColor Cyan -NoNewline "Client secret: "
Write-Host -ForegroundColor Yellow $clientSecret.SecretText
Write-Host -ForegroundColor Cyan -NoNewline "Secret expires: "
Write-Host -ForegroundColor Yellow $clientSecret.EndDateTime

if ($StayConnected -eq $false)
{
  Disconnect-MgGraph | Out-Null
  Write-Host "Disconnected from Microsoft Graph"
}
else
{
  Write-Host
  Write-Host -ForegroundColor Yellow `
   "The connection to Microsoft Graph is still active. To disconnect, use Disconnect-MgGraph"
}

Save the file.
Open PowerShell and change the current directory to the ___location of RegisterAppForAppOnlyAuth.ps1.

Run the following command.

.\RegisterAppForAppOnlyAuth.ps1 -AppName "Graph App-Only Auth Tutorial" -GraphScopes "User.Read.All"

Follow the prompt to open https://microsoft.com/devicelogin in a browser, enter the provided code, and complete the authentication process.

Copy the Client ID, Tenant ID, and Client secret values from the script output. You'll need these values in the next step.

SUCCESS
Client ID: ae2386e6-799e-4f75-b191-855d7e691c75
Tenant ID: 5927c10a-91bd-4408-9c70-c50bce922b71
Client secret: ...
Secret expires: 10/28/2024 5:01:45 PM

Note

Notice that, unlike the steps when registering for user authentication, in this section you did configure Microsoft Graph permissions on the app registration. App-only auth uses the client credentials flow, which requires that permissions be configured on the app registration. See The .default scope for details.

Create a Python console app

Begin by creating a new Python file.

Create a new file named main.py and add the following code.
```
print ('Hello world!')
```
Save the file and use the following command to run the file.
```
python3 main.py
```
If it works, the app should output Hello world!.

Install dependencies

Before moving on, add dependencies that you use later.

Azure Identity client library for Python to authenticate the user and acquire access tokens.
Microsoft Graph SDK for Python (preview) to make calls to the Microsoft Graph.

To install the dependencies, run the following commands in your CLI.

python3 -m pip install azure-identity
python3 -m pip install msgraph-sdk

Load application settings

Add the details of your app registration to the project.

Create a file in the same directory as main.py named config.cfg and add the following code.

[azure]
clientId = YOUR_CLIENT_ID_HERE
clientSecret = YOUR_CLIENT_SECRET_HERE
tenantId = YOUR_TENANT_ID_HERE

Update the values according to the following table.

Setting Value

clientId The client ID of your app registration

clientSecret The client secret of your app registration

tenantId The tenant ID of your organization

Tip

Optionally, you can set these values in a separate file named config.dev.cfg.

Setting	Value
`clientId`	The client ID of your app registration
`clientSecret`	The client secret of your app registration
`tenantId`	The tenant ID of your organization

Design the app

Create a console-based menu.

Create a new file named graph.py and add the following code to that file.
```
# Temporary placeholder
class Graph:
    def __init__(self, config):
        self.settings = config
```
This code is a placeholder. You implement the Graph class in the next section.

Open main.py and replace its entire contents with the following code.

import asyncio
import configparser
from msgraph.generated.models.o_data_errors.o_data_error import ODataError
from graph import Graph

async def main():
    print('Python Graph App-Only Tutorial\n')

    # Load settings
    config = configparser.ConfigParser()
    config.read(['config.cfg', 'config.dev.cfg'])
    azure_settings = config['azure']

    graph: Graph = Graph(azure_settings)

    choice = -1

    while choice != 0:
        print('Please choose one of the following options:')
        print('0. Exit')
        print('1. Display access token')
        print('2. List users')
        print('3. Make a Graph call')

        try:
            choice = int(input())
        except ValueError:
            choice = -1

        try:
            if choice == 0:
                print('Goodbye...')
            elif choice == 1:
                await display_access_token(graph)
            elif choice == 2:
                await list_users(graph)
            elif choice == 3:
                await make_graph_call(graph)
            else:
                print('Invalid choice!\n')
        except ODataError as odata_error:
            print('Error:')
            if odata_error.error:
                print(odata_error.error.code, odata_error.error.message)

Add the following placeholder methods at the end of the file. You implement them in later steps.

async def display_access_token(graph: Graph):
    # TODO
    return

async def list_users(graph: Graph):
    # TODO
    return

async def make_graph_call(graph: Graph):
    # TODO
    return

Add the following line to call main at the end of the file.
```
# Run main
asyncio.run(main())
```

This implements a basic menu and reads the user's choice from the command line.

Next step

Add app-only authentication

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Build Python apps with Microsoft Graph and app-only authentication

Prerequisites

Register application for app-only authentication

Create a Python console app

Install dependencies

Load application settings

Design the app

Next step

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