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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.
Netspell exists (https://github.com/loresoft/NetSpell) it's pretty nice, if you add it to your solution with nuget you'll be able to use it within your project. Otherwise using an online api of some kind (as Str_) suggests.
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