demo · v131
FedCM sign-in as a Storage Access trust signal
A successful FedCM credential counts as the user's prior interaction with the embedded origin, so Storage Access prompts can be auto-granted instead of throwing a confirmation. Step through the simulated flow below.
step 1embedded page loadscross-site iframe boots
step 2FedCM sign-in completesnavigator.credentials.get()
step 3document.requestStorageAccess()iframe asks for first-party storage
step 4browser decisionuses FedCM as trust signal
Press request Storage Access to see the outcome.
the api
// Inside the embedded iframe
const credential = await navigator.credentials.get({ identity: {/* FedCM config */} });
// In Chrome 131+ the browser records the FedCM grant as a Storage Access trust signal.
await document.requestStorageAccess(); // auto-grants when the signal is present