Novu is an open-source notifications platform with a unified API, workflow orchestration, and embeddable in-app inbox for email, SMS, push, and chat.

39.4k stars4.4k forkslast commit Actively maintained
Braze is a customer engagement platform for personalized cross-channel messaging (email, SMS, push, in‑app). It offers audience segmentation, journey orchestration and automation, real-time data activation, AI decisioning, and campaign analytics for lifecycle marketing.
Novu is an open-source notifications platform with a unified API, workflow orchestration, and embeddable in-app inbox for email, SMS, push, and chat.

39.4k stars4.4k forkslast commit Actively maintained
Self-hosted open-source marketing automation platform with campaign builder, email/landing page editors, REST API, segmentation, and extensible plugins.

10.2k stars3.4k forkslast commit Actively maintained
Open-source product analytics platform with SDKs for mobile, web and desktop; provides dashboards, events, crash reporting, messaging, A/B testing and APIs.

5.9k stars980 forkslast commit Actively maintained
Developer-focused platform for automated, omnichannel messaging (email, SMS, push, WhatsApp) with low-code journeys, segmentation, templates, and self-hosting.

2.9k stars368 forksMITlast commit Actively maintained
Open-source customer engagement and product onboarding platform for building event-triggered journeys and sending email, SMS, push notifications, and webhooks.
2.6k stars204 forkslast commit Actively maintained
Every option on this page is open source and free to run on your own hardware, so you own the data and there is no subscription to cancel. 5 of 5 shipped a commit in the last six months. Licences in this list: MIT. In exchange you take on hosting, backups and updates yourself.
Browse everything in Automation & Workflow Builders (Low-code).