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libfido2
Provides library functionality for FIDO2, including communication with a device over USB or NFC.
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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.
They suggest using this libfido2 library to connect with the hardware devices. I don't really know much about OSS licenses and which are the most "free" so you'll have to decide that for yourself.
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