The supported API for building client applications to interact with Hyperledger Fabric version 2.4 and later is the Fabric Gateway client API. Implementations are provided in Go, Node (TypeScript / JavaScript) and Java.
Legacy SDKs are available for Hyperledger Fabric versions prior to 2.4. Although these SDKs are no longer actively developed, they should continue to function with Fabric version 2.x releases. They will not work with Fabric 3.x using a BFT ordering service.