Prompt behavior with MSAL.js

  • Article

MSAL.js allows passing a prompt value as part of its login or token request methods. Based on your application scenario, you can customize the Microsoft Entra prompt behavior for a request by setting the prompt parameter in the request object:

import { PublicClientApplication } from "@azure/msal-browser";

const pca = new PublicClientApplication({
    auth: {
        clientId: "YOUR_CLIENT_ID"
    }
});

const loginRequest = {
    scopes: ["https://microsoftgraph.chinacloudapi.cn/user.read"],
    prompt: 'select_account',
}

pca.loginPopup(loginRequest)
    .then(response => {
        // do something with the response
    })
    .catch(error => {
        // handle errors
    });

Supported prompt values

The following prompt values can be used when authenticating with the Microsoft identity platform:

Parameter Behavior
login Forces the user to enter their credentials on that request, negating single-sign on.
none Ensures that the user isn't presented with any interactive prompt. If the request can't be completed silently by using single-sign on, the Microsoft identity platform returns a login_required or interaction_required error.
consent Triggers the OAuth consent dialog after the user signs in, asking the user to grant permissions to the app.
select_account Interrupts single sign-on by providing an account selection experience listing all the accounts in session or an option to choose a different account altogether.
create Triggers a sign-up dialog allowing external users to create an account.

MSAL.js will throw an invalid_prompt error for any unsupported prompt values:

invalid_prompt_value: Supported prompt values are 'login', 'select_account', 'consent', 'create' and 'none'. Please see here for valid configuration options: https://azuread.github.io/microsoft-authentication-library-for-js/ref/modules/_azure_msal_common.html#commonauthorizationurlrequest Given value: my_custom_prompt

Default prompt values

The following shows default prompt values that MSAL.js uses:

MSAL.js method Default prompt Allowed prompts
loginPopup N/A Any
loginRedirect N/A Any
ssoSilent none N/A (ignored)
acquireTokenPopup N/A Any
acquireTokenRedirect N/A Any
acquireTokenSilent none N/A (ignored)

Note

Note that prompt is a protocol-level parameter and signals the desired authentication behavior to the identity provider. It does not affect MSAL.js behavior and MSAL.js does not have control over how the service will ultimately handle the request. In most circumstances, Microsoft Entra ID will try to honor the request. If this is not possible, it may return an error response, or completely ignore the given prompt value.

Interactive requests with prompt=none

Generally, when you need to make a silent request, use a silent MSAL.js method (ssoSilent, acquireTokenSilent), and handle any login_required or interaction_required errors with an interactive method (loginPopup, loginRedirect, acquireTokenPopup, acquireTokenRedirect).

In some cases however, the prompt value none can be used together with an interactive MSAL.js method to achieve silent authentication. For instance, due to the third-party cookie restrictions in some browsers, ssoSilent requests will fail despite an active user session with Microsoft Entra ID. As a remedy, you can pass the prompt value none to an interactive request such as loginPopup. MSAL.js will then open a popup window to Microsoft Entra ID and Microsoft Entra ID will honor the prompt value by utilizing the existing session cookie. In this case, the user will see a brief popup window but will not be prompted for a credential entry.

Next steps