Blockchain development and use may often grow complex. There are tools available that help reduce this complexity, both for programmers and for non-technical audiences – APIs and SDKs. While the latter is aimed at blockchain developers, the former may be used both by developers and by technically-savvy end-users as well.
APIs use various software styles to enable their functionality. Representational State Transfer (REST) is the most popular API style. When using a REST-based API, you request data by providing a Uniform Resource Identifier (URI), a sequence of characters that uniquely identifies a web-based resource, e.g., a data file, a document, or a web page.
Crypto APIs are usually used by programmers as part of the software solutions they develop. Instead of developing the communication channel between two or more sources from scratch, programmers use pre-built APIs. The use of APIs can provide significant time savings on a blockchain development project.
However, some crypto APIs could also be used by technically-savvy users who do not necessarily have software development skills. These are usually the APIs that are well-documented and designed to be as user-friendly as possible.
Normally, the richer the functionality a crypto API offers, the harder it is for non-programmer audiences to use. Before trying to make use of any API, it is advisable to thoroughly study its documentation.