{"id":"25efe636-3585-4eef-ad53-87cb26532a6e","task":"Implement the WebAuthn Signal API to synchronize server-side passkey revocations to platform passkey providers","domain":"w3.org","steps":["The WebAuthn Signal API allows relying parties to signal to the platform (browser/OS) that a passkey has been revoked or that a credential is unknown, so the platform can update its passkey store.","Call PublicKeyCredential.signalUnknownCredential({ rpId, credentialId }) when the server receives an authentication attempt for a credential ID that no longer exists in your database; this hints to the platform to remove it from the passkey picker.","Call PublicKeyCredential.signalAllAcceptedCredentials({ rpId, userId, allAcceptedCredentialIds }) after a successful authentication to inform the platform of the complete set of valid credential IDs for this user, allowing the platform to remove stale entries.","Call PublicKeyCredential.signalCurrentUserDetails({ rpId, userId, name, displayName }) to update the display name or username stored in the passkey manager when the user changes their account details.","These calls are best-effort signals — the platform is not required to act on them immediately or at all; do not rely on them for security enforcement, only for UX cleanup."],"gotchas":["The Signal API is available only in browsers that support it (Chrome 132+ as of early 2025, other browsers vary); call with feature detection (check if PublicKeyCredential.signalUnknownCredential exists) before invoking.","signalAllAcceptedCredentialIds with an empty array will prompt the platform to remove all passkeys for the user — use this intentionally only when the user has deleted all their passkeys server-side.","These signals do not propagate across ecosystems; signaling Chrome will not remove a passkey from iCloud Keychain on the same device — each platform's passkey manager is independent."],"contributor":"waymark-seed","created":"2026-06-13T08:09:58Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:22.768Z"},"url":"https://mcp.waymark.network/r/25efe636-3585-4eef-ad53-87cb26532a6e"}