The SDK or API is an integration layer responsible for connection in the blockchain network. It's normally developed using Node.js and plays an important role in the calling of smart contracts. Today, we can find API/SDK documentation covering Go and Java, with documentation for Python on the horizon.
You can refer to this link for more information on how to use APIs/SDKs to integrate your application with a blockchain network: https://hyperledger-fabric.readthedocs.io/en/release-1.3/fabric-sdks.html.
The following diagram shows an application integrated with an API/SDK that interacts with Hyperledger Fabric:
Composer JavaScript SDK is derived from Node.js, and it allows developers to integrate your application with their business networks.
There are two npm modules:
- composer-client: This module is usually installed as a local dependency of an application. It provides the API that's used by business applications to connect to a business network in order to access assets and participants and submit transactions. When in production, this is the only module that needs to be added as a direct dependency of the application.
- composer-admin: This module is usually installed as a local dependency of administrative applications. This API permits the creation and deployment of business network definitions.
Now let's move on to the last layer in our solution.