What are some cloud notifications services that offer an HTTP API to initiate a notification and can send it to push (iOS, Android, browser), SMS, slack etc.<p>Nice to have: support some escalation rules and feedback from the receiver of the notification.<p>Preferable with a free tier or at least low cost tier.<p>Thanks
I’ve used OneSignal and their generous free tier in the past with great success. It has nifty features like using an external user ID (your backend can just say: send a message to @user123). I had to switch to Firebase Cloud Messaging for compatibility reasons but I still highly recommend OneSignal.
Since you're looking for free or low cost, how about self hosting?<p>Gotify allows push notifications to Android.<p>NodeRED can expose an API and trigger actions such as SMS through plugins.