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JWTs have three sections: a header, payload (containing a claim set), and signature. The header and payload are JSON objects, serialized to UTF-8 bytes, then encoded using base64url encoding. Note that ClearBlade has strict JWT base64url encoding requirements, unlike Google.
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The header’s algorithm must match at least one of the public keys registered for the device.
Note: The JWT header differs from the HTTP header (if you're connecting over HTTP).
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