# Firefox for Android’s Play Integrity check hits custom ROMs

> Source: <https://www.omgubuntu.co.uk/2026/06/mozilla-firefox-android-google-play-integrity>
> Published: 2026-06-09 20:55:58+00:00

Mozilla has added support for Google’s Play Integrity API, known for blocking users of custom ROMs from accessing banking apps, to Firefox for Android. Per a resolved issue in Mozilla’s public tracker, a new lib-integrity-googleplay library was added to Firefox’s Android codebase. It requests a Play Integrity token which is then passed to Mozilla’s MLPA (Machine Learning Proxy) server. The token is used to access Firefox’s server-side AI tools, like Smart Window, for rate-limiting purposes, ensuring only unmodified, Play-installed copies of Firefox on Google-certified devices use Mozilla’s compute infra. Per documentation for the API, developers can: “…call the Integrity API […] to […]

You're reading [Firefox for Android’s Play Integrity check hits custom ROMs](https://www.omgubuntu.co.uk/2026/06/mozilla-firefox-android-google-play-integrity), a blog post from [OMG! Ubuntu](https://www.omgubuntu.co.uk). Do not reproduce elsewhere without permission.