What is meant by application programming interface?

An application programming interface (API) is a set of programming codes that queries data, parse responses, and sends instructions between one software platform and another. APIs are used extensively in providing data services across a range of fields and contexts.

APIs have become increasingly popular tools, with the likes of Meta (formerly Facebook), Amazon, SalesForce, and many more establishing their own APIs that allow companies to access some of their services without having to fully migrate into their ecosystem. This new paradigm has led to the rise of what some experts call the "API economy," a model that enhances a company’s bottom line by improving interoperability and thus creating new systems from existing ones.

In the domain of financial markets and trading, one may use an API to establish a connection between a set of automated trading algorithms and the trader's preferred trading broker platform for the purpose of obtaining real-time quotes and pricing data or to place electronic trades.

Key Takeaways

  • An application programming interface (API) establishes an online connection between a data provider and an end-user.
  • For financial markets, APIs interface trading algorithms or models and an exchange's and/or broker's platform.
  • An API is essential to implementing an automated trading strategy.
  • More brokers are making their platforms available through an API.

Understanding Application Programming Interfaces (APIs)

APIs have become increasingly popular with the rise of automated trading systems. In the past, retail traders were forced to screen for opportunities in one application and separately place trades with their broker. Many retail brokers now provide APIs that enable traders to directly connect their screening software with the brokerage account to share real-time prices and place orders. Traders can even develop their own applications using programming languages like Python and execute trades using a broker's API.

Two types of traders use broker APIs:

  • Third-Party Applications - Many traders use third-party applications that require access to broker APIs for pricing data and placing trades. For example, MetaTrader is one of the most popular foreign exchange (forex) trading applications and requires API access to secure real-time pricing and place trades.
  • Developer Applications - A growing number of traders develop their own automated trading systems, using programming languages like Python, and require a way to access pricing data and place trades.

Despite the apparent benefits of APIs, there are many risks to consider. Most APIs are provided to a broker's customers free of charge, but there are some cases where traders may incur an extra fee. It's important to understand these fees before using the API.

Traders should also be aware of any API limitations, including the potential for downtime, which could significantly affect trading results.

Where to Find APIs for Traders

The most popular brokers supporting API access in the traditional stock and futures markets include TradeStation, TDAmeritrade, and InteractiveBrokers, but many smaller brokers have expanded access over time. APIs are more common among forex brokers where third-party applications and trading systems—such as MetaTrader—have been commonly used for many years.

Many brokers provide online documentation for their APIs. Developers can find out exactly how to authenticate with the API, what data is available for consumption, how to place orders through the API, and other technical details. It's essential to be familiar with these details before choosing a broker when looking for specific functionality.

Some brokers also provide libraries in various languages to make interaction with their API easier. For example, a broker may offer a Python library that provides a set of functions, or methods, for placing a trade rather than having to write your own functions to do so. This can help accelerate the development of trading systems and make them less costly to develop.

An application programming interface (API) is a set of protocols, routines, functions and/or commands that programmers use to facilitate interaction between distinct software services.

APIs allow one software service to access data from another software service without the developer's needing to know how the other service works. For example, the U.S. Postal Service’s Open APIs allow e-commerce developers to add package tracking to their websites so customers know when to expect delivery.

An API can be seen as composed of two fundamental elements: a technical specification that establishes how information can be exchanged between programs (which itself is made up of request for processing and data delivery protocols) and a software interface that somehow publishes that specification. Although APIs can work with any common programming language, the most popular approach to delivering web APIs is REST (REpresentational State Transfer). A RESTful API architecture uses HTTP coding for much of its functionality.

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Techopedia Explains Application Programming Interface (API)

APIs give authorized third-party partners “behind the firewall” access to specific data types.

The basic concept behind the API has existed in some form for the entire history of digital technology, as the interaction between unique programs and digital systems has been a primary objective for much of that technology's existence. But with the rise of the world wide web, and the subsequent turn-of-the-millennium dot-com boom, the incentive for this technology reached an unprecedented level.

The API became especially prominent in the burgeoning commercial sector of the world wide web in early 2000, when Salesforce.com incorporated the technology into its platform in order to help customers share and transmit data over their diverse business applications. Soon after that, eBay began rolling out similar technology, and with the rise of social media a few years later, companies like Flickr, Facebook, Twitter and Instagram began doing the same.

APIs are available for both desktop and mobile use, and are useful for programming GUI (graphic user interface) components, as well as allowing one software program to request and accommodate services from another program.

What is Application Programming Interface?

What is an application programming interface (API)? An application programming interface, or API, enables companies to open up their applications' data and functionality to external third-party developers and business partners, or to departments within their companies.

What is Application Programming Interface with example?

An example is the Apple (iOS) API that's used to detect touchscreen interactions. APIs are tools. They allow you as a programmer to deliver solid solutions fairly rapidly. If you have to rebuild everything from scratch every time, your solutions will be cumbersome.

What are the 4 types of API?

There are four principal types of API commonly used in web-based applications: public, partner, private and composite. In this context, the API "type" indicates the intended scope of use.

What is an application vs an API?

The biggest difference between an API (Application Programming Interface) and an App (short for application) is how each impacts the user. Both offer some form of connectivity, but while APIs are intended to be used by software applications, software applications themselves are intended to be used by humans.