v136 · miscellaneous

FedCM multi IDP in single get() call and remove add accounts in passive mode

Allows FedCM to show multiple identity providers in the same dialog. This provides developers with a convenient way to present all supported identity providers to users. We are planning to first tackle the simple case of having all providers in the same get() call.

concepts

  1. Multi-IdP

    FedCM can negotiate with multiple IdPs in one get() call. Users pick which provider in the browser UI; sites don't have to gate on per-IdP detection.

  2. Passive-mode add-account removal

    The other half of the v136 change: switch between passive (auto) and active (gesture-required) mediation modes — the "Add account" row disappears in passive.

  3. IdP List Composer

    Drag together a multi-IdP call shape, set each provider's context and the call's mediation mode, then watch the validator catch the two v136 rule changes: only one IdP can request add, and passive-mode add is rejected.

  4. Conflict resolver

    Simulate two IdPs returning overlapping accounts (same email in both). See how the chooser groups them by IdP, understand why each entry is a separate credential (not a duplicate), and explore how the user picks which IdP to authenticate through.

why it shipped

Currently, the FedCM API enables RPs to show federated login prompts to users without requiring the use of third-party cookies. However, the API only supports showing one IDP at a time. Many RPs support more than one IDP, so extending the API to allow showing more than one IDP will benefit these RPs and let users choose an account from the IDP of their choice.

references