Compatibility with Fabric versions

hlf-core works with Hyperledger Fabric 2.x and 3.x: both on the chaincode side (fabric-shim) and on the client side. In practice this means that the framework can be deployed onto both an already running 2.x network and a fresh 3.x one, without changing application code: the version differences are hidden inside the @hlf-core/api and @hlf-core/transport layers.

If you are planning a new network, it is reasonable to take the current 3.x line. But if you already have a deployed Fabric 2.x, there is no need to move to a newer version for the sake of hlf-core — it will support that one too.