Top 10 Financial APIs: Stripe, PayPal, World Bank Group

With more and more people using digital payments for purchasing online products and services, it’s no surprise that finance APIs are among the most popular on ProgrammableWeb. While the top 10 financial APIs list includes APIs for a wide range of capabilities, quite a few of the APIs in the list provide access to full-featured digital payments platforms or involve digital payments.

These days, newer companies like Dwolla and Stripe are giving long-established companies such as PayPal, 2Checkout, and Authorize.Net a real run for their money. It will be very interesting to see where these digital payment companies stand in the coming months.

The APIs that made it to our top 10 financial APIs list provide capabilities such as processing online payments, retrieving global financial data, accessing currency exchange rates, and much more. The APIs also scored well against a diverse set of criteria:

  • Popularity
  • Potential
  • Documentation
  • Ease of Use
  • Functionality

API popularity is determined using a variety of metrics including PW followers, GitHub activity, Twitter activity, and search engine popularity based on Google Trends.

There were several APIs that while popular, did not quite have the metrics to make it into the top 10 financial APIs list. These APIs are well worth mentioning and include ZohoCRM, Xero Software, American Express, and PaymentBloomberg.


Link: /api/stripe
Provider: Stripe
API Documentation URL:

Stripe, a leading digital payment solutions provider, publicly launched in September 2011 and initially served customers in the United States. Since the launch, Stripe has expanded its digital payment services to 20 countries including Australia, Canada, Denmark, Finland, Ireland, and the United Kingdom. According to a recent Bloomberg Business article, Stripe has formed several key partnerships with companies including Apple, China-based Alibaba, and Twitter. Stripe is now integrated with Apple Pay, has added support for Alipay to Stripe Checkout, and provides digital payments services for Twitter. In addition, Stripe and Braintree (owned by PayPal), will be handling the payments for Pinterest’s newly launched Buy Button feature.

The company provides nicely organized API documentation that includes example projects, API client libraries, plugins for third-party software, toolkits for iPhone and Android, full API Reference, an in-depth subscription service walkthrough, and much more.

Stripe has expanded its digital payments services to 20 countries in the span of four years and the Stripe API now holds the No. 1 position in the ProgrammableWeb top 10 Financial APIs list. It will be interesting to see what kind of success Stripe achieves in the coming months.


Google Search Interest Over Time - Data Source: Google Trends


Link: /api/paypal
Provider: PayPal
API Documentation URL:

PayPal was founded back in 1998 and currently has over 165 million active customer accounts. In 2014, eBay announced that PayPal will be separated from eBay and will become an independent publicly traded company in 2015. PayPal has recently received widespread criticism regarding its updated user agreement which goes into effect July 1st. The updated user agreement allows the company to contact customers by phone, robocall, or text about promotions, debt collection, and company surveys. On June 11th, the FCC sent a letter to PayPal warning that the updated user agreement may cause the company to be in violation of the Telephone Consumer Protection Act.

PayPal provides a well-organized developers site that contains comprehensive documentation for PayPal mobile SDKs, REST APIs, and classic APIs. PayPal’s REST APIs are hypermedia-style APIs, each call including an array of Hypermedia as the Engine of Application State (HATEOAS) links. PayPal provides a Sandbox environment for testing and there are SDKs available for Ruby, Python, Node.js, PHP, Java, and C#.

PayPal is a well-established, well-known digital payments company that many consumers use on a daily basis. How the company handles the issues related to the updated user agreement could have an impact on PayPal’s future success.


Google Search Interest Over Time - Data Source: Google Trends

World Bank Group

Link: /api/world-bank
Provider: World Bank
API Documentation URL:

The World Bank Group provides low-interest loans, grants, and other financial services to developing countries around the world. The World Bank Group is not a traditional bank; the primary goals of the organization are to help end extreme poverty and promote shared prosperity for all countries. In April 2010, the World Bank opened up a significant portion of its data, which can be used by anyone for free, and can be accessed using the World Bank Open API.

The World Bank Open API provides access to income level, lending types, world development indicators, and other types of data for over 200 countries going back more than 50 years. There are over 8,000 indicators that can be accessed via API including total population, gross national income, gross national expenditure, trade (% of GDP), etc.

The API documentation is well organized and there is a World Bank API query builder that can be used to configure country calls, data calls, and topic calls. The World Bank also offers the option of embedding indicators using copy and paste widgets. Much of the indicator data can be embedded as a table, map, or graph.


Google Search Interest Over Time - Data Source: Google Trends

Open Exchange Rates

Link: /api/open-exchange-rates
Provider: Open Exchange Rates
API Documentation URL:

Open Exchange Rates provides real-time and historical (back to 1999) rates for about 165 world currencies. The data is collected from various sources then combined, normalized, and converted to JSON format which can be retrieved using the Open Exchange Rates API. The API is free to use for personal use and there are paid plans for developers that would like to use the API for commercial projects.

The API documentation is a one-page document that is well organized and easy to follow. At the time of this writing, there are code examples provided for JavaScript, Node.js, and PHP. There is a nice page on the website that showcases apps using the Open Exchange Rates API, such as Nomad List, ExpenseShare, and Kindful.


Google Search Interest Over Time - Data Source: Google Trends


Link: /api/kiva
Provider: Kiva
API Documentation URL:

Kiva is a nonprofit organization that leverages a network of microfinance institutions on five continents in order to provide microfinancing to people who do not have access to traditional banking systems. Since Kiva’s launch in 2005, the total amount lent through Kiva is $718,839,975, the repayment rate is 98.71%, and the average loan size is $415.86.

The Kiva developer site is nicely organized, easy to follow, and provides a lot of detailed information about the Kiva API. There is a comprehensive API reference page, code samples, SDKs, and a small gallery of apps using the Kiva API.


Google Search Interest Over Time - Data Source: Google Trends


Link: /api/2checkout
Provider: 2Checkout
API Documentation URL:

Founded in 2000, 2Checkout is a leading payment services provider that supports transactions in 196 countries. The 2Checkout Platform features global payments, hosted checkout, shopping carts, fraud protection, a Payment API, and more.

The 2Checkout developers site is nicely designed and features comprehensive, well-organized API documentation as well as a sandbox for testing, knowledge base, cart Integration instructions, and more. At the time of this writing, there are SDKs available for PHP, Ruby, Python, Node.js, Java, and .Net.

2Checkout seems to be growing steadily and within the last two years, the company has formed partnerships with several companies, including FreshBooks, WooThemes, Shopify, and Brink’s.


Google Search Interest Over Time - Data Source: Google Trends


Link: /api/freshbooks
Provider: FreshBooks
API Documentation URL:

FreshBooks is a leading cloud-based accounting platform that provides tools for users to quickly create professional-looking invoices and estimates, accept credit card payments, track expenses, and more. In July 2014, Co-founder and CEO Mike McDerment announced that the company had secured its first round of funding in the amount of $30M USD, which is being used to further improve the FreshBooks platform and help increase worldwide adoption of the software.

FreshBooks provides a basic developers site that includes a lot of detailed information about the FreshBooks API. The documentation includes links to Sample Code, helper libraries, information about Webhooks, and more.


Google Search Interest Over Time - Data Source: Google Trends

OANDA fxTrade

Link: /api/oanda-fxtrade
Provider: OANDA
API Documentation URL:

OANDA fxTrade is a forex trading platform that was launched in 2001 and designed to reduce trading costs and speed up execution. OANDA fxTrade is cloud-based and there is no installation required; however, the software runs on and requires Java. The platform is designed primarily for traders, investment managers, financial institutions, and enterprises.

The OANDA API site is nicely designed and organized with a suite of APIs and tools for developers which includes an HTTP-based REST API, Java SDK, MetaTrader 4 (MT4), and Financial Information eXchange (FIX). The API site features comprehensive API documentation, API comparison chart, an Apigee console, API status dashboard, sample code, and more.


Google Search Interest Over Time - Data Source: Google Trends


Link: /api/dwolla
Provider: Dwolla
API Documentation URL:

Dwolla is a digital payment platform that allows users to request, send, and receive funds via bank transfers. Earlier this year, Dwolla was selected to be a live payment option (alongside PayPal) for the U.S. Department of the Treasury’s Bureau of the Fiscal Service digital wallet service In April of this year, the company announced a partnership with BBVA Compass, allowing BBVA Compass customers to send and receive real-time payments using Dwolla’s payment network. Earlier this month, the company announced the removal of the $0.25 per transaction fee for all Dwolla users and all transaction types.

The Dwolla developers site features an active forum, API status page, sandbox for testing, token generator, and more. The API documentation is comprehensive and very nicely designed (powered by Slate). The documentation includes JSON response examples, helper libraries, and sample code for PHP, Ruby, Python, and Node.js.

Dwolla’s independent, credit-card free, digital payment platform has been quickly gaining traction in recent months. Dwolla is now used by many individuals for sending and receiving money online and the platform has been integrated with a number of large banking institutions and government agencies.


Google Search Interest Over Time - Data Source: Google Trends


Link: /api/
Provider: Authorize.Net
API Documentation URL:

Founded in 1996, Authorize.Net is a leading payment gateway services provider offering products that enable online payments, mobile payments, fraud detection, automated recurring billing, and more. Authorize.Net is integrated with many popular shopping carts and financial software including Magento, PrestaShop, Shopify, and Xero. Authorize.Net also recently added Apple Pay support to its platform.

Authorize.Net provides a developer site that contains comprehensive API information, code samples, SDKs, sandbox, sample applications, and more. There is a fairly new getting started guide with detailed instructions and videos as well as a comprehensive, interactive API reference guide (beta).

Authorize.Net is a well-established, reliable, digital payments processing company and currently has over 400,000 merchant customers. There seems to be very little news in recent years when it comes to Authorize.Net, however. With companies like Stripe and Dwolla forming major partnerships and quickly gaining popularity with consumers, it will be interesting to see if Authorize.Net will continue to retain its current customer base.


Google Search Interest Over Time - Data Source: Google Trends


Disclaimer: The metrics used to determine ProgrammableWeb's top 10 Financial APIs were obtained shortly before the time of publication. The metrics used, pricing, and other product information provided in this article is accurate as of the time of publication.

Be sure to read the next Financial article: Thomson Reuters Launches Open Source Market Data APIs