Hyperledger client SDK is a component used to interact with Fabric network. It resides outside of the Fabric network but connected with its own Membership Service Provider (MSP) and network connection profiles. So, the SDK is actually the part in the business flow that interacts with the customer, and therefore it can be hosted anywhere.
- It can be a web application that acts as a front end, having the fabric as the back-end
- It can be a phone application that a user has
- It can be even an IoT device on a RaspBerry Pi that simply logs periodically real world data into the blockchain
- It can be a service that interacts with other services inside a data center.