In the world of software development, understanding the difference between SDKs and APIs and their uses and benefits can be invaluable.
Software development is a complex field, and SDKs and APIs can make this complexity more manageable for developers of any level.
However, every useful tool needs to include documentation that helps get the most out of it.
Technical writers have the knowledge and skills to make great documentation for SDKs and APIs. But first, they need to learn what each of them entails.
Let’s get started!
What Is SDK Documentation
SDK documentation is crucial for software developers who want to be consistent and efficient.
That type of documentation accompanies SDKs, so before delving any deeper into it, we have to answer one question—what is an SDK?
SDK stands for software development kit. Here’s how Keerthi Rangan, content management and SEO specialist, explains it:
In other words, it’s helpful to think about it as a literal kit that has various tools which make developers’ work easier.
Similar to, for instance, a toolbox for mechanics, SDK has a wide range of specific tools for software developers.
Sure, a skilled mechanic can improvise with what he or she has at the moment, but it’s far more efficient and logical to have everything needed in one place.
The same goes for software developers.
Also, SDKs are specific, as Rangan mentioned above. That means they differ based on a specific programming language, platform, or framework.
For instance, ClickSend has ten different SDKs.
That way, developers can choose what they need based on the programming language they create software in.
So, what is in an SDK? Here are some of the things it can contain:
- Code libraries
- Code samples
As you can see, documentation is also a part of it.
It’s a resource that helps developers understand and use the tools in the SDK and create new software with it.
It can include tutorials, code snippets, installation guides, etc. As its purpose is to accompany an SDK, the contents depend on the toolkit it comes with.
For example, below, you can see what a part of Stripe’s SDK documentation for Android looks like.
As you can see, it’s a setup guide for installing the SDK. The instructions are straightforward, and the guide provides a helpful code example.
At this point, you probably understand why it can be important to have SDK documentation.
Let’s go into more detail about those reasons in the next section.
Why Is SDK Documentation Important
In the previous section, we already touched on the reason why SDK documentation is important.
Essentially, it guides developers through using all the helpful parts of an SDK. Now, let’s go into the specifics of what that means.
SDKs are immensely valuable in software development because they can make the development process quicker and more streamlined.
Developers have the tools necessary to create software on different platforms.
For instance, SDKs usually have code samples for Android, iOS, and websites, and developers can use and reuse those samples as they see fit.
Take a look at the example from Amity. If a developer wants to add a function of mentioning someone in the comments or replies in iOS, all they have to do is add the code you can see below.
That’s important because they don’t have to write it from scratch whenever they want to implement that function, saving them time for other work.
As you can also see from the link above, Amity writers created documentation for their SDKs so that developers could know all the properties related to the mentioned function, and how it works, see an example of what it looks like in a comment, etc.
That way, the developers get all the context and information about the function.
In other words, great SDK documentation has significant educational value.
For instance, without Google’s SDK documentation, this developer wouldn’t have learned how to style Google Maps in Android.
Luckily for developers, Google has comprehensive SDK documentation.
It includes everything they need, like tutorials, links to the code for specific functions, step-by-step instructions, API keys, styling wizard, etc.
In a nutshell, SDKs are very valuable to developers.
They create conditions for a more efficient workflow, reduce the need for repetitive work, make integrations with other software easier, etc.
They’re like the Swiss Army knives of software development.
But they also need well-written documentation to go along with them to put all of those valuable tools into context and provide instructions on how, when, where, and why to use them.
SDK vs. API Documentation: Key Differences
SDKs and APIs can be easily confused because they share certain similarities. However, there are some key differences between them, as well as between their documentation.
For starters, let’s define what an API is.
It stands for application programming interface, and as the author and web developer Kristopher Sandoval, puts it, it’s basically a way of communication between different pieces of software.
As he further explains, an API is like a translator between two languages so that two instruction sets can be transferred and understood by different pieces of software.
Keerthi Rangan, whom we’ve mentioned earlier, gives an example of an API that connects Google calendar and travel software.
That way, when a user schedules a trip in the travel software, the API synchronizes with the calendar and inputs the same trip into it.
It's at this point that we look at API documentation. Its purpose is to provide instructions on how to use and integrate API effectively.
For instance, how to do precisely what we just described—integrate Google Calendar and your app.
In other words, API documentation tells developers what to do with APIs, how to do it, provides use cases, samples, ways to handle errors, etc.
The crucial difference between API documentation described above and SDK documentation is that the former can be a part of the latter, but not the other way around.
In short, APIs are one of the components of SDKs, one of the tools in the toolbox that is SDK. And they have the specific purpose of allowing communication between pieces of software.
On the other hand, SDKs contain tools for building whole systems and creating entire applications—something APIs can’t be used for.
Therefore, SDK documentation, like Twilio’s below, has instructions and information about all of those tools, including APIs.
To sum up, API documentation can be a part of SDK documentation, but not vice versa.
Likewise, APIs are a part of the kit, while SDKs are an entire kit.
How to Write Good SDK Documentation
As we’ve established by now, SDK documentation is undeniably useful.
However, because of its complexity, producing high-quality SDK documentation can be a real challenge for a technical writer.
One reason is that SDKs are not the same for every programming language.
For example, as Tom Johnson, a technical writing expert and blogger, points out, PayPal has SDKs for Node JS, PHP, Python, Ruby, Java, etc.
Of course, those are different programming languages and frameworks, so a technical writer can’t create documentation that is universally applicable to all of them.
So, there is comprehensive documentation just for PHP SDK, for example.
And creating detailed documentation like that is a tall order.
A technical writer needs to have a good understanding of the programming language he writes the documentation for. Otherwise, it simply can’t be useful as a guide for developers.
Tom Johnson shares some more insights on this matter:
When deciding whether to call a block of code a function, class, method, or another name, you need to have a basic understanding of the terms used in that language.
While we’re on the topic of understanding the terms, you shouldn’t assume that a developer is an expert in every programming language you write SDK documentation for.
Therefore, a glossary of terms can benefit them, elevating the usefulness of SDK documentation.
For instance, Microsoft included a glossary of terms for their Visual Studio SDK documentation.
That makes reading complex technical documentation like SDK documentation more manageable.
Another great addition to the SDK documentation you can make is to include code samples.
They show the reader exactly what the code for a specific feature looks like, but they also make the documentation more readable by breaking up large chunks of text.
Below you can see what that looks like in Nexweave’s SDK documentation.
Its documentation is built in Archbee, a platform great for creating all sorts of documentation, including SDK.
In addition to implementing code samples, which you can see above, Archbee has helpful collaboration features that can make a technical writer’s job a lot easier.
For instance, writers can collaborate directly in documents with developers and other experts who can check for any mistakes or help writers with particularly complex parts.
That way, SDK documentation will be accurate, and any issues noticed in proofreading can be easily corrected by anyone with permission to edit.
Good SDK documentation is challenging to create, but with the tips we’ve discussed in this section, it’s a challenge that you can undoubtedly conquer.
Differentiating between SDK and API documentation can be difficult at times.
That’s because they sometimes contain similar information and are both highly technical in nature.
However, we hope that we’ve cleared the confusion with this article.
SDKs and APIs are immensely useful tools for developers, and creating quality documentation for them is crucial for getting the most out of them.