ZeroMQ socket is in and tested, now working on CurveZMQ (CurveCP for ZeroMQ). We had this in v3, but with the full ZeroMQ dependency (what would also now be a Libsodium dependency given that ZMQ dropped Tweet NaCl). This is so much simpler, since all we implement is ZMQ framing as an ASIO stream, and Curve as a privacy stream (same as the Boost Beast TLS stream, and our custom bip324 P2P privacy stream).
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