API: programming interfaces for data transmission.
API is an acronym we are gradually becoming familiar with, albeit a little more slowly than with others perhaps because the concept it represents is not as trivial as is the impact that APIs are having in the field of computing, finance and beyond. Even if we already know what they are, it is important to stop and reflect on the importance these elements have in the current panorama and how they are allowing the financial world to evolve towards a new paradigm in which those who collaborate win; no longer those who compete by closing themselves in their fortresses.
APIs: what they are and the exchange of instructions between parts of the programme.
The acronym API stands for Application Programming Interface, and therefore refers to interfaces that enable communication between different software applications, even if they are written in different programming languages. It sounds like a banal and obvious concept, but it is not. It is revolutionary in terms of what APIs can do. We can imagine them as an access point to another piece of software through which two programmes can communicate with each other, exchange data and issue commands. These new modes of freedom for programmers affect desktop software as well as web applications and mobile devices: it is now possible anywhere to build a single program so that different modules communicate with each other thanks to these interfaces that standardise the transmission of data and the exchange of instructions between the parts of the program.
APIs: what they are used for and how they interface programmers with software components.
Having understood what Application Programming Interfaces are and that they open up a greater number of degrees of freedom to a programmer’s range of action, we can get down to the nitty gritty and imagine what actions become possible in this new set-up in which numerous software producers make APIs available to facilitate programmers’ access to software components. Developers can use the interfaces made available by SAP, Amazon and Google, for example, but to do what?
For reusing app code through program interaction, to embed content in web services, to forward a programmer’s command to the software and receive a response, or control access of other programmers.
Even if we don’t often realise it, Application Programming Interfaces are also present in the sites we use on a daily basis, allowing us to perform certain actions that we take for granted but which would be impossible without these last. Think about when you want to book a hotel in Paris, obviously at the best price, through a site that is able to find it for you. By clicking on search we start the process and from that moment the website communicates with the APIs of the various hotel chains to check prices and availability. Everything happens in a few seconds and without our knowledge.
How API interfaces and the REST protocol work.
Although they have an impact on the end user, APIs are, and remain, in the hands of programmers to whom they are usually provided by software developers. These interfaces define how information and data is received and returned between modules. and for convenience, a specific standard is used to which external software must adhere. This is where the REST protocol comes in. and we talk about REST APIs when they use the same commands as HTTP, making the exchange of information simple and the connection of programmers to the API more fluid. Standardisation is certainly at the heart of this mechanism, regardless of the protocol used for the exchange. Essential for everything to work, however, is the preparation of the programmers, who must be ‘trained’ in detail on the syntax and functions of the APIs they are going to use.
The 4 types of API.
There are four main classes of Application Programming Interface that we can encounter today:
Protocol-oriented: for standardised communication between programs, regardless of operating systems or hardware.
Function-oriented: for accessing hardware components (only functions are always called).
File-oriented: allowing connectivity at the file level.
Object-oriented: can be used flexibly.
A second distinction can also be made between private and public interfaces. The former are APIs that are only available within a certain company and are mostly used to connect proprietary functionalities for employees to access via private networks. Public interfaces are accessible to everyone and are used by software developers, and they are the ones who often make them public inviting them to use them and develop APIs in turn.
Benefits of using API interfaces.
Both internal and external developers have seen their work improve thanks to these programming interfaces, and have gained greater flexibility and ‘creative’ power. External developers can freely extend the functionality of their software by linking up with other applications, while internal developers can benefit from greater dissemination by equipping their programs with good programming interfaces. Finally, there are also benefits for all users, who can enjoy more convenient and high-performant services and applications precisely because Application Programming Interfaces allow a more agile and extensive combination of different programmes that previously did not speak so well of each other.