1.novuhq / novuThe open-source communication infrastructure for agents and productsnotificationscommunicationemailsmspush-notificationstransactional+9 moreTypeScriptOther license40K total4.5K forks+959 starsfrom 39,288 · score 6.87
2.dittofeed / dittofeedOpen-source customer engagement. Automate transactional and marketing messages across email, SMS, mobile push, WhatsApp, Slack, and more 📨open-sourcetypescriptjavasciptcustomer-engagementcustomer-segmentationemail-notification+14 moreTypeScriptMIT3K total423 forks+163 starsfrom 2,874 · score 5.10
3.invertase / react-native-firebase🔥 A well-tested feature-rich modular Firebase implementation for React Native. Supports both iOS & Android platforms for all Firebase services.firebaseanalyticsandroidiosdatabasepush-notifications+14 moreTypeScriptOther license12K total2.3K forks+46 starsfrom 12,279 · score 3.85