Entra App Registration

## Overview

Microsoft Entra ID (formerly Azure Active Directory) is Microsoft's cloud-based identity and access management service. App registrations allow applications to authenticate users and access Azure resources securely.

### Key Concepts

| Concept | Description | |---------|-------------| | **App Registration** | Configuration that allows an app to use Microsoft identity platform | | **Application (Client) ID** | Unique identifier for your application | | **Tenant ID** | Unique identifier for your Azure AD tenant/directory | | **Client Secret** | Password for the application (confidential clients only) | | **Redirect URI** | URL where authentication responses are sent | | **API Permissions** | Access scopes your app requests | | **Service Principal** | Identity created in your tenant when you register an app |

### Application Types

| Type | Use Case | |------|----------| | **Web Application** | Server-side apps, APIs | | **Single Page App (SPA)** | JavaScript/React/Angular apps | | **Mobile/Native App** | Desktop, mobile apps | | **Daemon/Service** | Background services, APIs |

## Core Workflow

### Step 1: Register the Application

Create an app registration in the Azure portal or using Azure CLI.

**Portal Method:** 1. Navigate to Azure Portal → Microsoft Entra ID → App registrations 2. Click "New registration" 3. Provide name, supported account types, and redirect URI 4. Click "Register"

**CLI Method:** See [references/cli-commands.md](references/cli-commands.md) **IaC Method:** See [references/BICEP-EXAMPLE.bicep](references/BICEP-EXAMPLE.bicep)

It's highly recommended to use the IaC to manage Entra app registration if you already use IaC in your project, need a scalable solution for managing lots of app registrations or need fine-grained audit history of the configuration changes.

### Step 2: Configure Authentication

Set up authentication settings based on your application type.

- **Web Apps**: Add redirect URIs, enable ID tokens if needed - **SPAs**: Add redirect URIs, enable implicit grant flow if necessary - **Mobile/Desktop**: Use `http://localhost` or custom URI scheme - **Services**: No redirect URI needed for client credentials flow

### Step 3: Configure API Permissions

Grant your application permission to access Microsoft APIs or your own APIs.

**Common Microsoft Graph Permissions:** - `User.Read` - Read user profile - `User.ReadWrite.All` - Read and write all users - `Directory.Read.All` - Read directory data - `Mail.Send` - Send mail as a user

**Details:** See [references/api-permissions.md](references/api-permissions.md)

### Step 4: Create Client Credentials (if needed)

For confidential client applications (web apps, services), create a client secret, certificate or federated identity credential.

**Client Secret:** - Navigate to "Certificates & secrets" - Create new client secret - Copy the value immediately (only shown once) - Store securely (Key Vault recommended)

**Certificate:** For production environments, use certificates instead of secrets for enhanced security. Upload certificate via "Certificates & secrets" section.

**Federated Identity Credential:** For dynamically authenticating the confidential client to Entra platform.

### Step 5: Implement OAuth Flow

Integrate the OAuth flow into your application code.

**See:** - [references/oauth-flows.md](references/oauth-flows.md) - OAuth 2.0 flow details - [references/console-app-example.md](references/console-app-example.md) - Console app implementation

## Common Patterns

### Pattern 1: First-Time App Registration

Walk user through their first app registration step-by-step.

**Required Information:** - Application name - Application type (web, SPA, mobile, service) - Redirect URIs (if applicable) - Required permissions

**Script:** See [references/first-app-registration.md](references/first-app-registration.md)

### Pattern 2: Console Application with User Authentication

Create a .NET/Python/Node.js console app that authenticates users.

**Required Information:** - Programming language (C#, Python, JavaScript, etc.) - Authentication library (MSAL recommended) - Required permissions

**Example:** See [references/console-app-example.md](references/console-app-example.md)

### Pattern 3: Service-to-Service Authentication

Set up daemon/service authentication without user interaction.

**Required Information:** - Service/app name - Target API/resource - Whether to use secret or certificate

**Implementation:** Use Client Credentials flow (see [references/oauth-flows.md#client-credentials-flow](references/oauth-flows.md#client-credentials-flow))

## MCP Tools and CLI

### Azure CLI Commands

| Command | Purpose | |---------|---------| | `az ad app create` | Create new app registration | | `az ad app list` | List app registrations | | `az ad app show` | Show app details | | `az ad app permission add` | Add API permission | | `az ad app credential reset` | Generate new client secret | | `az ad sp create` | Crea