Novu

Novu gives you one API for all your notifications: email, SMS, push, in-app, and chat, replacing the duct tape of Twilio, SendGrid, Firebase, and Slack APIs. Define a notification workflow once, and it handles routing to the right channel based on user preferences.

The open source version (self-hosted) is free and includes the core workflow engine, template management, subscriber preferences, and all channel integrations. The managed cloud has a free tier with 30,000 events/month, then $250/mo for the Business tier.

Self-hosting runs via Docker Compose with MongoDB, Redis, and the Novu workers. Setup takes 1-2 hours and the docs walk you through it. Moderate ops burden. You're running a multi-service stack with queues and a database. Solo developers: the cloud free tier at 30K events/month covers most side projects. Small teams: cloud free tier still works unless you're sending heavy volume. Growing teams: self-host to avoid per-event costs or pay $250/mo for managed.

The catch: Novu has pivoted its architecture multiple times. The latest version (v2) shifted to a code-first approach which is cleaner but broke backward compatibility. If you adopted v1 patterns, migration takes work.