Want to learn how to develop apps? One of the first things you need to do is understand APIs.

All manner of tasks can be completed with APIs, from scraping websites for data to tracking weather, flights, and even automating social networking posts. Here, we take a look at how to get started with API automation using Fixer.

What Is an API?

An Application Programming Interface (API) is a piece of software that allows two (or more) applications to communicate. Most daily tasks requiring a website or mobile app are centered around APIs. Phone dialers and messaging apps, social networks, weather apps – they all rely on APIs.

Such applications don’t deal directly with the underlying database that provides information to the app. Instead, the API exists as an intermediary, a go-between that takes instructions from the user, communicates with the server, grabs the information from the server, and returns it to the user.

APIs have been likened to waiting for staff in a restaurant, taking a customer order, handing it to the chef, then returning with your order.

However, an API might just as easily be compared with the steering system of a modern car. You handle the steering wheel, pedals, and gears (the app), and any actions are transferred to data (the API) and communicated to the steering machinery and engine (the server).

What Can You Do With an API?

Many types of API are available. Operating systems feature APIs for everything from creating dialog boxes to accessing the device camera. Many free APIs are available, particularly for web applications.

APIs can typically be accessed with popular programming languages. When it comes to web APIs, languages such as PHP, JavaScript, or anything else suitable for web development can be used.

With an API and suitable programming knowledge, you can develop an app that provides useful information, with data supplied through the API. Consider a news app, or one that monitors stocks and shares.

Convert Currency With Fixer, an API Providing Forex Rates

An example API that you can start developing with right now is Fixer.

Fixer offers an API that provides the tools to create an app for currency conversion or checking foreign exchange (Forex) rates on 170 world currencies.

Note, however, that Fixer demands a monthly subscription for anything over the basic 100 API calls per month. This isn’t unusual with API providers, so keep this in mind before proceeding. However, Fixer can be used free for development purposes, and under 100 API calls.

Get started with the base URL: 

        https://data.fixer.io/api/

Each Fixer account gets an API key, which can be used to authenticate the API call 

        https://data.fixer.io/api/latest

? access_key = API_KEY

Fixer returns data in JSON format, enabling easy parsing by your chosen programming language. Functions can also be specified with JSONP callbacks, which will wrap the callback response in the desired function name.

All currencies are relative to the base currency. Specifying a base currency is important for developing an app for use outside the EU. Fixer uses the Euro (EUR) as its base currency. To change this use a different base currency in the API call, for example: 

        https://data.fixer.io/api/latest

? access_key = API_KEY

& base = USD

& symbols = GBP,JPY,EUR

Fixer’s comprehensive API documentation provides further information.

APIs Help You Build the Apps Your Users Need

With Fixer, you can automate currency conversion queries and monitor Forex data. Numerous endpoints are provided, for the latest rates, conversion, historical rates, data between two dates, and even fluctuations.

Meanwhile, with a paid subscription you can use HTTPS and provide a secure connection for users of any app developed with Fixer.

But Fixer is just one of many APIs that enable developers of all levels to create useful mobile, desktop, and web applications.