Back in late August, Nothing unveiled Nothing OS 5.0 based on Android 17 and opened its beta to the Phone (3). The program has since expanded to more devices, and the Phone (3) is already receiving the stable version. Today the open beta is becoming available for the Nothing Phone (2a) and Phone (2a) Plus.
To join, download the latest Nothing Beta Hub app from Nothing's website and install it, then go to Settings > System > Nothing Beta Hub, tap Check version, and then Join Beta. The open beta build should then arrive as an over-the-air update within a few minutes. This is unfinished software, so back up your data first, because rolling back to a stable version through Request Rollback in the same menu wipes your phone.
Nothing OS 5.0 brings a visual refresh with a new system font, a redesigned Settings menu, a new default home screen theme, new lock screen clock faces, a dedicated Glyph app, separate notifications and Quick Settings, live updates in the status bar, and MCP support in Essential Space, among plenty of other changes listed in the full changelog.
The stable version of Nothing OS 5.0 should reach the Phone (2a) and (2a) Plus in mid-November. The Phone (4b) is next in line for the open beta in mid-December, while the Phone (3a) Lite and CMF Phone 2 Pro skip it and get the stable release in late December and mid-January, respectively. If you own a Phone (1), Phone (2), or CMF Phone 1, you're out of luck, as Nothing says these have reached the end of major software support and won't get Nothing OS 5.0 at all.