How eBay’s Buy APIs Hit $5 Billion in Gross Merchandise Bought

eBay’s Buy APIs enable third-party developers to surface eBay inventory in their shopping experience, allowing consumers to purchase items without visiting an eBay site.

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At eBay, we have a large, powerful and vibrant ecosystem of third-party applications. For us, APIs are the foundation of the business-to-developer model and are instrumental in achieving business objectives and overall success. We treat our APIs as first-class products that democratize access to our marketplace platform — and we share the success with our partners.

We launched the developers program in November 2000, and the initial set of APIs brought a lot of value to our platform. Some of them are still heavily used and are important to our customers, but changes in the e-commerce space made it clear that it was time to revisit our portfolio to accelerate growth in the space. That’s why in 2016 we decided to completely revamp our developers program and deliver new, modern RESTful APIs.

In addition to agreeing on standards and patterns, the essential step was defining the API taxonomy. We classified our capabilities into four contexts:

  • Sell — includes APIs for sellers to manage their eBay business at scale.
  • Buy — encompasses capabilities that allow surfacing eBay items on third-party shopping sites and placing orders from anywhere online.
  • Commerce — consists of capabilities that benefit both buy and sell integrations.
  • Developer — provides insights to developers into their integration with our APIs.

By the end of 2020, our Buy APIs reached a significant milestone, surpassing more than $5 billion in cumulative GMB (Gross Merchandise Bought), as calculated from January 2017 to December 2020. Here is how we achieved that.

Buy APIs

eBay brings more than one billion listings together to surface the greatest inventory selection to our partners. This includes new, everyday items as well as rare, unique finds. If something exists in the world, you can most likely find it on eBay. Our focus is on enabling a shopping experience that is simple and data-driven, allowing buyers to find, compare and purchase items they need and want. The requirements for high-volume and low-latency buying radically influenced our API capabilities.

Four Buy APIs contributed most to the overall GMB milestone.

  • The Browse API gives partners access to eBay’s powerful in-house search capabilities. The API also supports creating a search refinement experience by further filtering responses by key aspects (e.g., brand, color, size).
  • The Feed API allows authorized developers to curate, mirror and surface eBay inventory at scale.
  • The Order API enables secure checkout for guests and members from anywhere online, without visiting eBay sites or using eBay’s native apps. Also, it provides updates on order status, shipment tracking details and expected delivery dates.
  • The Offer API allows buyers to place proxy bids and retrieve bidding details.

In addition to the above four APIs, partners leverage other APIs in our portfolio to integrate with various parts of their business — like the Deal API to retrieve deals and sales events, and the capabilities from our Commerce family of APIs. The Taxonomy API allows developers to understand the eBay taxonomy and choose the best categories to surface for their end-users. The Translation API is based on in-house models and state-of-the-art algorithms optimized for e-commerce that translate item titles and descriptions, helping cross the language barrier. Finally, the Charity API enables partners to discover the 101,000 charitable organizations supported on eBay, and to contribute to the more than $1 billion in funds raised by eBay for Charity since 2003.

How We Reached $5 Billion in 4 Years

What brings value to the APIs are successful integrations. APIs are the building blocks that developers use to create great experiences for their users. Not all API integrations are created equal, and third parties innovate by putting these building blocks together in unique ways.

Listen, Learn and Evolve 

While delivering APIs, it is crucial to partner with trusted developers and solicit direct feedback to help shape strategies and roadmaps. The design-first method allows the API providers to continuously evolve the interface while iterating with consumers. Initially, we released all our Buy APIs as a beta. We focused on building relationships with trusted partners, traversed the globe to meet them, and gathered feedback as often and as early as possible.

Indirect feedback is equally important. The API usage analysis points to workarounds and missing capabilities in the API portfolio. With that, accurate insights — including operational and business metrics — are among the main drivers to enhancing API capabilities.

Simplifying the Developer Experience

Delivering an API is only half the work. It’s important to consider the overall developer experience, by enabling tools that improve developer productivity and simplify integration in order to boost adoption. We joined the OpenAPI Initiative in 2017 to make it easier and faster for developers to integrate with our APIs. The OpenAPI specification is the industry standard for describing APIs. For all our RESTful APIs, we have OpenAPI documents published — which allow developers to call our APIs in no time.

Software development kits (SDKs) are another set of tools that improve developer productivity. In our case, they abstract some of the concepts — like the integration with our authorization services. An example is the Feed SDK. Since our data feeds are large and include the greatest selection of eBay inventory, the Feed SDK abstracts the file manipulation and simplifies the inventory curation. Our SDKs are open-sourced, to give developers full transparency into their integration with our APIs (and we appreciate contributions from our developer community).

Communication and Connection

Keeping your developer partners informed and connected is key to a successful partnership. Since 2017, we have been hosting the eBay Connect conference, where we showcase our new APIs and eBay’s top initiatives to our developer ecosystem. We have had numerous developer events worldwide — including in Japan, China, the U.K., Germany, Australia and Israel. The global pandemic did not prevent us from connecting with our top developers. Over the summer, we held our fourth — and this time virtual — Connect Developer Conference. Despite all of the challenges, we look forward to another great year of events and partnerships in 2021.

A Culture of Innovation

Delivering successful APIs for our developers is only made possible when the team is empowered to innovate. In the Developer Ecosystem organization, we nurture a blameless culture that is beyond just DevOps. Our team members are encouraged to innovate boldly on our customers’ behalf every day. Flexibility and joy are key to people feeling safe to take risks and try new things.

As an example of our innovative culture, last year we leveraged our API portfolio for a good cause, by partnering with the U.K. National Health Service (NHS) to launch a portal for distribution of personal protective equipment (PPE) to health care providers across the country. The integration with eBay is via Buy APIs, and our team worked diligently to deliver this solution within days. This integration was recently recognized by Modern Retail Awards in their Most Responsible Retailer category. But most importantly, we are all incredibly proud to have delivered more than 1 billion PPE items since launching in April 2020 and to have the opportunity to help save lives.

Continuous APIfication

2020 was the year of integration. The global pandemic turned many aspects of life digital, and continuous APIfication allows organizations like eBay to interact with customers more efficiently and more frequently. Getting great at digital enables agile business and adds a lot of flexibility. APIs play a critical role at eBay, so we will continue giving developers tools to propel their business and create great experiences for their users — who, in the end, are our customers. Our goal is always to share the success with our partners. To stay informed, please visit eBay’s developer portal.

This article was initially published on The New Stack on Feb. 4, 2021.