Using MSAL Node with the macOS Broker

Microsoft Authentication Library (MSAL) Node can use the macOS authentication broker to provide single sign-on (SSO) and secure token acquisition by using accounts known to the operating system. This article explains the macOS broker and how to enable and use brokered authentication in MSAL Node.

For an overview of broker support across all platforms, see Using MSAL Node with the Native Token Broker.

What is the macOS broker

On macOS, the authentication broker is provided by the Microsoft Enterprise SSO plug-in for Apple devices, which ships with the Company Portal app. The broker manages authentication handshakes and token lifecycle for connected accounts. Key benefits include:

• Enhanced security. Security improvements are delivered via broker updates without requiring app code changes. Refresh tokens are device-bound and protected from exfiltration.
• System integration. Users can reuse existing signed-in accounts from Company Portal, reducing credential re-entry.
• Token protection. The broker ensures refresh tokens are bound to the device context.

Supported platforms and architectures

Prerequisites

• Node.js 18 or later
• Install @azure/msal-node-extensions as a dependency
• The device must be enrolled via Company Portal. After enrollment, verify that other Microsoft apps can sign in via the SSO extension (for example, you can sign in to Word via Company Portal).
• Register the broker redirect URI on your app registration. For the supported URI values, see Redirect URI.

Redirect URI

For macOS broker flows, you must register a platform-specific redirect URI under the Mobile and desktop applications platform in the Azure portal.

For unsigned applications (scripts, CLI tools):

Use the following redirect URI for unsigned applications, such as scripts and CLI tools:

msauth.com.msauth.unsignedapp://auth

For signed/bundled applications:

Use the following redirect URI format for signed or bundled applications:

msauth.<your-bundle-id>://auth

Replace <your-bundle-id> with your application's Apple bundle identifier (e.g., msauth.com.example.myapp://auth).

Enable the feature

Enabling the macOS broker requires the same configuration as Windows. Pass a NativeBrokerPlugin instance in the broker configuration:

import { PublicClientApplication, Configuration } from "@azure/msal-node";
import { NativeBrokerPlugin } from "@azure/msal-node-extensions";

const msalConfig: Configuration = {
    auth: {
        clientId: "your-client-id",
    },
    broker: {
        nativeBrokerPlugin: new NativeBrokerPlugin(),
    },
};

const pca = new PublicClientApplication(msalConfig);

Acquiring tokens

Interactive token acquisition

Use acquireTokenInteractive to request a token through the macOS broker:

const tokenRequest = {
    scopes: ["User.Read"],
};

const result = await pca.acquireTokenInteractive(tokenRequest);
console.log("Access token:", result.accessToken);

Silent token acquisition

After an initial interactive sign-in, subsequent token requests can be made silently:

const accounts = await pca.getAllAccounts();

if (accounts.length > 0) {
    const silentRequest = {
        scopes: ["User.Read"],
        account: accounts[0],
    };

    const result = await pca.acquireTokenSilent(silentRequest);
    console.log("Access token (silent):", result.accessToken);
}

Token caching

The authentication broker handles refresh and access token caching. Tokens acquired through the broker are managed by the broker itself and are device-bound. You don't need to set up custom caching when using the broker.

Differences when using the macOS broker

• When the broker needs to prompt for interaction, a native macOS authentication dialog appears. This changes the user experience (UX) compared to browser-based authentication.
• The forceRefresh parameter for acquireTokenSilent is not supported. You may receive a cached token from the broker regardless of this flag.
• Access token proof-of-possession (PoP) is supported through the broker.

Limitations

• Azure AD B2C and Active Directory Federation Services (AD FS) authorities are not supported via the macOS broker.
• Third-party identity providers (IDPs) are not supported.
• Company Portal must be installed and the device must be enrolled for the broker to function.
• msal-node does not fall back to a browser if the broker is unavailable. Only enable the broker in environments that support it.