These APIs work inside a very standard systems architecture. Typically, end users will have a presentation tier running on their web browser or mobile device. This will communicate with an application server tier, using an API that is defined by the application according to the overall solution being developed. This application tier might be running in the cloud or on an on-premise system. It's where all the application logic for the application resides, and it is the consumer of the business network APIs provided by the blockchain. This application may be doing other work, such as accessing a database, or performing analytics—but from our perspective, it's the interaction point with the blockchain network. It consumes the blockchain APIs, not the end-device. Summarized, these APIs operate within a typical 3-tier systems architecture structure of presentation, application, and resource management.

Alternatively, if we have a device or system interacting with the blockchain, then it will not have a presentation tier—it will either use the application API or blockchain APIs directly. In a very real sense, a device is the presentation tier, and the system is the application tier. Again, this is all very standard.