After finalizing the blockchain instance, we need to work with API's, which will be used by developers to make applications interact with the blockchain. Usually, most of the platforms already provide predefined API's. If we require to build a blockchain platform from scratch, then we might have to look into the design and schemas for API's. Carefully as per our requirement, we need to make sure that only those API's are available, which are required for the applications and there is no leakage of information through our API's. Moreover, we can also add permissions or rules over API's. Some of the most used API's that might be required for the blockchain project could be generation of keepers, asset issuance, dot authentication, and so on.

Key generation API will be used by the users to generate private key and addresses, which is valid for the blockchain. Asset issuance provides features to generate assets over the blockchain. dot authentication can be used to verify and authenticate the data. Reading the blockchain parameter could be used to retrieve information about the blockchain. Apart from functional API's, we could also add the API's to manage addresses over the blockchain. Like we can add API's to check addresses balance, or check address permission.

We can also make API's available for the processes running on top of the blockchain, like the creation of smart contracts, or integrating with the smart contracts. We always need to make sure that only those API's are up available for your platform, which are required by the developers and applications. We don't need to reveal much of the information to everyone. And we also don't need a solution where nothing is visible. As no API's are provisioned. We need to find a balance for API's on over platform.

Now finally, everything is said and we are ready for over end users. So in the next step, we will see how you can define the applications for your end users.