Today, APIs are essential for building high-performance, scalable applications. But what is an API? How do they work? And how do we use them in our platforms?
Simply put, an API is an Application Programming Interface. It enables applications to communicate with each other and exchange information according to predefined standards and conditions. The most important thing you need to know about an API is the list of functions it enables you to call up directly within a computer program, without knowing exactly how it works. In effect, an API exposes a service to another application, but does not frame the execution of the processing behind it.
The APIs we naturally think of are those that expose the services of the application to which they are attached. In the case of social networks, for example, the data in a Facebook publication is not the same as that in a Twitter publication, due to the structure of the publication, which is very specific to each social network. As a result, each network has voluntarily developed its own API to enable the exchange of data, making this programming interface central to the application's development strategy.
On the other hand, the service offered by an API may be of public utility. In this case, the API is standardized for widespread use by different players. Today, for example, open banking/DSP2 is a service offered by all banks and made possible thanks to the functionalities of payment APIs. Unlike Facebook, banks are obliged by regulation to develop these payment APIs, whose signature (i.e. the function contract) is standardized.
Please note:
Here are a few concrete examples of APIs in our daily lives:
There are several types of API: repositories, SOAP, REST... This article is not intended as a catalog of programming interfaces. If you'd like to know more about this subject, we invite you to read articles specifically devoted to the different types of API (such as this article or this video):
In this article, we'll be focusing on how the REST APIs we use in our platforms work . REST APIs were first developed in the 2000s, and have gained widespread acceptance in recent years thanks to their simple, flexible operation. They are web APIs, meaning that they operate via the Internet by means of calls in the form of http requests, the web's communication protocol.
More concretely, REST uses http requests (with the secure https version) via various methods, the main ones being: GET - PUT - POST - DELETE. In return for a request sent in the form of a URL link to the API, the latter will generate an action adapted to the method used during the request:
This action can take different formats (JSON, XML etc.) depending on the choice of the API sender. For response integration, the JSON (JavaScript Object Notation) format is generally used, as it is lighter and less verbose than XML (Extensible Markup Language).
To learn more about how a REST API works, we recommend you watch this video.
ESG Connect is a SaaS (Software as a Service) platform we have developed to democratize socially responsible investment by connecting data, teams and financial players.
We have integrated existing APIs to take advantage of services offered by other applications such as :
At the same time, we developed our own APIs via the AWS API Gateway cloud service to enable the two existing parts of our platform to communicate.
As a reminder, a platform generally consists of the :
Our APIs enable the exchange of financial or non-financial data (structured or unstructured) between the two parties, which is then stored in a database (in our case DynamoDB, a NoSQL database). In more technical terms, the APIs enable data to be exchanged between Angular (the frontend) and our lambda functions (Python), which in turn communicate with DynamoDB.
Why would you want to integrate this data into such a database?
An example: integrating data from a new provider
The difficulty lies inintegrating any type of ESG data source (excel/pdf) in which the provider's information is contained, and then controlling the quality of this new data.
The first step is to define the parameters of the integrated data. At the outset of the project, we defined a set of data we wanted to retrieve from suppliers: ESG scores, ESG KPIs, Controversies, Screening, Climate (2° Alignment, etc.), SDGs, Commitment, Votes... (non-exhaustive list).
Parameters are defined according to the data source (for Excel, for example, we will select only the few columns containing the data we are interested in). The long-term objective is to standardize data processing for all suppliers.
Secondly, data is loaded and integrated into the database via the APIs we have developed.
Orion is a platform for comparing the offerings of ESG data providers, currently listing over 60 suppliers. Thanks to this "TripAdvisor of ESG data", any user can find the supplier best suited to their needs in just a few searches.
To achieve this, we have used services exposed by various existing APIs, such as :
We have also developed our own REST APIs to display on-screen the results of a user's search on the providers. The providers' catalog is based on a database stored in the cloud backend, whose information is fed back to the front end after each search via APIs.
In a nutshell, APIs are capable of collecting, processing and analyzing complex, unstructured data more optimallyand more quickly than in-house developments would have allowed.
APIs have facilitated the connection of multiple data sources and the integration of new services/features into our platforms, making them more dynamic and efficient.
