Intent to Ship: Web Authentication Immediate UI mode

[Ken Buchanan]

Contact emails

ke...@chromium.org, der...@google.com

Explainer

https://github.com/w3c/webauthn/wiki/Explainer:-WebAuthn-immediate-mediation

Specification

https://github.com/w3c/webauthn/pull/2291

Design docs

https://github.com/w3c/webauthn/wiki/Explainer:-WebAuthn-immediate-mediation

Summary

A new mode for navigator.credentials.get() that causes browser sign-in UI to be displayed to the user if there is a passkey or password for the site that is immediately known to the browser, or else rejects the promise with NotAllowedError if there is no such credential available. This allows the site to avoid showing a sign-in page if the browser can offer a choice of sign-in credentials that are likely to succeed, while still allowing a traditional sign-in page flow for cases where there are no such credentials.

Blink component

Blink>WebAuthentication

Web Feature ID

webauthn

Motivation

Most sign-in experiences on the web use sign-in pages that offer multiple options for accessing an account, such as username/password input fields, federated sign-in buttons, and sometimes explicit WebAuthn or passkey buttons. When the browser is aware of passkeys or passwords that the user has for the site, this API mode makes the sign-in page unnecessary by instead showing simple browser account selection UI when the user begins a sign-in attempt. Signing in with this flow reduces friction and avoids user confusion from having to remember which sign-in option they have used previously on a given site. The main difference between this and current modal WebAuthn sign-in UI is that for users without any such credentials, no browser UI will be shown, and their sign-in experience will be unchanged from what it is today (typically, a navigation to the site's sign-in page).

Initial public proposal

https://github.com/w3c/webauthn/issues/2228

TAG review

https://github.com/w3ctag/design-reviews/issues/1092

TAG has closed its review with unsatisfied on the basis that they do not believe a modal browser dialog is preferable to a form for user sign-in experiences. There was extensive discussion of this topic on both the TAG review issue and the WebAuthn WG issue.

This conflicts with the feedback we have received from developers of major relying parties who believe this enables them to build meaningfully better user experiences. They believe that a modal dialog that appears only when passkeys are available will be more successful for users attempting to sign in. Additionally, achieving the goal of signing in a user while keeping them in the current page context is very difficult with the current API.

Apple has stated that it supports the goals of this mode, but has objected on a different basis from TAG. It favors an alternative API form that it believes will have better privacy properties (https://github.com/w3c/webauthn/issues/2228#issuecomment-3443764943). Notably, Apple's proposal and Immediate mode would be invoked in different situations, and are not mutually exclusive.

Since Immediate mode does not guarantee that UI will be shown on invocation, we maintain flexibility to tweak this later in ways that limit its use.

TAG review status

Issues addressed

Origin Trial Name

Immediate Mediation for Passkeys and Passwords

Chromium Trial Name

WebAuthenticationImmediateGet

Origin Trial documentation link

https://github.com/w3c/webauthn/wiki/Explainer:-WebAuthn-immediate-mediation

WebFeature UseCounter name

kCredentialsGetImmediateMediationWithWebAuthnAndPasswords

Risks

Interoperability and Compatibility

Gecko: No signal (https://github.com/mozilla/standards-positions/issues/1239)

WebKit: Negative (https://github.com/WebKit/standards-positions/issues/504) Feedback is on the WG issue: https://github.com/w3c/webauthn/issues/2228#issuecomment-3443764943

Web developers: Positive (https://github.com/w3c/webauthn/issues/2228#issuecomment-3999513181)

Other signals:

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

No information provided

Debuggability

No information provided

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

Yes
https://wpt.fyi/results/webauthn/getcredential-ui-mode-immediate.https.html?label=master&label=experimental&aligned&q=getcredential-ui-mode-immediate.https.html

DevTrial instructions

https://docs.google.com/document/d/18iV5eUBM4NVoNx0gqPSxPyJAjPdrfIR75vcMDBewzZU/edit?tab=t.0#heading=h.uj0x12ysuohk

Flag name on about://flags

web-authentication-immediate-get

Finch feature name

WebAuthenticationImmediateGet

Rollout plan

Will ship enabled for all users

Requires code in //chrome?

True

Tracking bug

https://issues.chromium.org/issues/408002783

Launch bug

https://launch.corp.google.com/launch/4394539

Measurement

Use counters: CredentialsGetImmediateMediationWithWebAuthnAndPasswords CredentialsGetImmediateMediationWithWebAuthnOnly CredentialsGetImmediateMediationWithPasswordsOnly We are also tracking user interactions with the modal UI that will be shown when this is used.

Estimated milestones

Shipping on desktop	147
Origin trial desktop first	139
Origin trial desktop last	141
Origin trial extension 1 end milestone	144
DevTrial on desktop	136
Shipping on Android	147
DevTrial on Android	142
Shipping on WebView	147

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5164322780872704?gate=5177075746734080

Links to previous Intent discussions

Intent to Prototype: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CALjHGKrQEs4TDzuzb%3D0B00S4OmkE4a1NbZGi19sCueTKvN_m9w%40mail.gmail.com
Ready for Trial: https://groups.google.com/a/chromium.org/g/blink-dev/c/zC13ioLIZ_E/m/P-P6B6gNCQAJ
Intent to Experiment: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CALjHGKpJkA9G6De6D4%3DRNSbLMRdy8Yfa6B%3DgDNWeqTyHfv8sSg%40mail.gmail.com
Intent to Extend Experiment 1: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CALjHGKpLbqYVnSMfNgxh45TSbP9j6AU2JvLWow%3DH1ihr5v%2Bj0A%40mail.gmail.com

This intent message was generated by Chrome Platform Status.