Overview of the Microsoft Authentication Library (MSAL)

The Microsoft Authentication Library (MSAL) enables developers to acquire security tokens from the Microsoft identity platform to authenticate users and access secured web APIs. It can be used to provide secure access to Microsoft Graph, other Microsoft APIs, third-party web APIs, or your own web API. MSAL supports many different application architectures and platforms including .NET, JavaScript, Java, Python, Android, and iOS.

MSAL gives you many ways to get tokens, with a consistent API for many platforms. Using MSAL provides the following benefits:

• No need to directly use the OAuth libraries or code against the protocol in your application.
• Acquires tokens on behalf of a user or application (when applicable to the platform).
• Maintains a token cache and refreshes tokens for you when they're close to expiring. You don't need to handle token expiration on your own.
• Helps you specify which audience you want your application to sign in. The sign in audience can include personal Microsoft accounts, social identities with Azure AD B2C organizations, work, school, or users in sovereign and national clouds.
• Helps you set up your application from configuration files.
• Helps you troubleshoot your app by exposing actionable exceptions, logging, and telemetry.

Application types and scenarios

Using MSAL, a token can be acquired for many application types: web applications, web APIs, single-page apps (JavaScript), mobile and native applications, and daemons and server-side applications.

MSAL can be used in many application scenarios, including the following:

• Single page applications (JavaScript)
• Web app signing in users
• Web application signing in a user and calling a web API on behalf of the user
• Protecting a web API so only authenticated users can access it
• Web API calling another downstream web API on behalf of the signed-in user
• Desktop application calling a web API on behalf of the signed-in user
• Mobile application calling a web API on behalf of the user who's signed-in interactively.
• Desktop/service daemon application calling web API on behalf of itself

Languages and frameworks

Library	Supported platforms and frameworks
MSAL for Android	Android
MSAL Angular	Single-page apps with Angular and Angular.js frameworks
MSAL for iOS and macOS	iOS and macOS
MSAL Go (Preview)	Windows, macOS, Linux
MSAL Java	Windows, macOS, Linux
MSAL.js	JavaScript/TypeScript frameworks such as Vue.js, Ember.js, or Durandal.js
MSAL.NET	.NET Framework, .NET Core, Xamarin Android, Xamarin iOS, Universal Windows Platform
MSAL Node	Web apps with Express, desktop apps with Electron, Cross-platform console apps
MSAL Python	Windows, macOS, Linux
MSAL React	Single-page apps with React and React-based libraries (Next.js, Gatsby.js)

Migrate apps that use ADAL to MSAL

Active Directory Authentication Library (ADAL) integrates with the Azure Active Directory (Azure AD) for developers (v1.0) endpoint, where MSAL integrates with the Microsoft identity platform. The v1.0 endpoint supports work accounts, but not personal accounts. The v2.0 endpoint is the unification of Microsoft personal accounts and work accounts into a single authentication system. Additionally, with MSAL you can also get authentications for Azure AD B2C.

For more information about how to migrate to MSAL, see Migrate applications to the Microsoft Authentication Library (MSAL).