If you are professionally inclined – like I am – to read all about the business of APIs, you may have gotten the impression that APIs are going to take over everything and bring world peace.
Okay, I’m exaggerating but it is sometimes hard to remember that an API is really just a means to an end. That (business) end can vary. It might mean reaching more or different customers using mobile apps. It might mean integrating with partners. It might also mean giving access to services or data that provide enough value for them to be monetized. But in the end, I’m not using an API for the sake of using an API but because I want to use the services or data served by the API with the least amount of friction to myself because I – as a developer – have a job to do.
So here I am, using APIs via libraries/SDKs. In fact, I am not even sure when I last implemented a client using API documentation. In terms of priority, I only care if the service offered through the API meets my (business) needs – and then I use its library. And if it doesn’t have one, I might just move right along and look for the next one. (Remember: I have a job to do!)
For most developers out there in the real world, does consuming an API mean consuming an SDK that implements the API via a library? Should we talk about portable library design, efficient library loading (eager or lazy, async or sync) etc? Which platforms do I need to support to maximize my developer reach? What are the tradeoffs between offering (and having to support) a number of libraries versus just the API? Do dynamically-loaded libraries solve the API versioning challenge?
In any case, none of this reduces the importance of providing a well-designed and documented API. Libraries and SDKs simply provide a convenient wrapper around an API and APIs are about removing friction. And client libraries are just another few steps in the march towards frictionless integration. (I still remember fondly the ease with which I was able to create client stubs and OSGI bundles from WSDL during the Web service days.) Nevertheless, we at Layer 7 – as an API Management company – will certainly be looking into how we can provide more support for client libraries in the future.
The preference for using client libraries rather than developing API clients becomes even more pronounced if we look at the Internet of Things.
Almost all the IoT integration vendors I have talked to consider supporting a large amount of client libraries for the myriad different IoT platforms to be one of their key differentiators in the market. Partly, this is driven by the need to optimize client stacks for resource-constrained platforms but it is also driven by the emergence of new binary and publish-subscribe protocols designed to better deal with IoT’s asynchronous communications patterns (see this blog post for a good overview).
While there has been quite some activity around API definition languages lately, I’m not aware of any attempt to provide a formal description language for asynchronous APIs of this type. Maybe this is an area where we will see some new ideas and innovation in the coming months.