4.0.0 (2025-10-20)

react-native-mmkv V4 is the next major evolution of the library - it features:

• A full rewrite to Nitro! 🔥
  • ..this implies that V4 now works again on the old-architecture, until react-native 0.82 at least.
• react-native-mmkv V4 now uses MMKVCore from CocoaPods/Gradle instead of shipping it as source - this means you can use the native MMKV library from your native code again without causing duplicate symbols!
• Make set(...) throw a useful Error when the value couldn't be saved
• Adds useMMKVKeys()
• Make remove(...) return a bool
• Add AppGroup again
• Make remove(...) and clearAllKeys() invoke listeners properly

‼️ Before upgrading, please read the V4 upgrade guide. ‼️

✨ Features

• add React Native Harness (#918) (cbcb4bd)
• Throw if set(...) was not successful (#921) (0d3b833)
• Upgrade MMKVCore to 2.2.4 (Android) (#912) (cf77676)
• Upgrade Nitro to 0.30.0 (#923) (03dd7c9)
• Upgrade to Nitro 0.31 (#929) (176e4f3)
• Upgrade to react-native 0.82.0 (#930) (5f7d595)

🐛 Bug Fixes

• Fix example app build for Xcode 26 (#922) (965a549)
• Notify listeners when keys get removed (remove/clearAll) (#920) (09643c3)
• Throw if key is empty in set(...) (#919) (3d3b793)