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InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
Tsec - https://github.com/jmcardon/tsec.
I would look at Pac4J which works with Akka HTTP.
Another option is to use Keyclock which is a seperate service but very popular and has lots of features.
I haven't found it that steep, yet. I mean, no steeper than any other OpenId stuff. It's not Auth0 easy, though, you are correct.
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