A brief history of the TM Forum Open APIs

I spent most of Q4 2020 researching the TM Forum Open APIs for our new report, How to lead in the Open API economy. The idea was to take an independent and critical look at the interfaces, exploring not only how companies are using them (and plan to use them), but also what the primary challenges are to adopting them. In addition, we wanted to find out what it will take for the Open APIs to become the de facto standard in telecoms. During the next several weeks, we’ll publish highlights of the report here on Inform. This edited excerpt from its introduction explains how the Open APIs got their start. Next week we will look at what’s driving Open API adoption.

In December 2013, 150 coders crowded into a conference room in San Francisco, the first-ever public users of TM Forum’s new Open APIs. There were only three at the time: the Product Catalog API, Product Ordering API and Trouble Ticket Management API. The idea was to demonstrate how standard interfaces could make operators more attractive to developers and easier to do business with.

The event offered $6,000 in cash prizes and featured teams working feverishly into the night to create applications ranging from ecommerce and office-in-a-box to management of prison inmates’ needs. The winners of the hackathon used the APIs to develop an app that allowed users to offer goods for trade with no money changing hands. The team used the Product Catalog API to show listings, the Product Ordering API to handle the exchange and the Trouble Ticket Management API to share offer status.

“When we ran that hackathon in San Francisco, it was a risky but important exercise,” says Joann O’Brien, the Forum’s VP of Digital Ecosystems. “We had really been trying to ‘de-telcoize’ the APIs and had been out there saying they could be used anywhere. The success of that event was groundbreaking.”

The hackathon was the first of many to publicly demonstrate the power and versatility of the Open APIs, which have been developed by member companies under the guidance of TM Forum Chief API Architect Pierre Gauthier to solve common challenges to IT integration and help operators participate in platform-based digital ecosystems. BT, Orange and Vodafone Group are Open API pioneers. As Dr. Lester Thomas, Chief Systems Architect at Vodafone Group, explained when the Open API program was formally launched in 2016:

“We strongly believe that there’s an ecosystem model we need to adopt. So, between operating models we need to have integration based on these Open APIs, and also, we build it in a way that we can expose these services even to external partners… In the [Vodafone operating companies] which have adopted this most strongly, we’re seeing in excess of 60% of demand-driven re-use – more than 60% of the time, that market can meet new demand through existing APIs. That’s huge agility, huge time-savings, and of course it’s a huge cost savings as well.”

Thomas, Laurent Leboucher, VP of Digital IT, Customer Relations and Global Architecture at Orange, and George Glass, who was previously Chief Systems Architect at BT and is now the Forum’s CTO, recorded the videos below in 2016 to explain why their companies were pioneering the Open API initiative.





The Open APIs are technology agnostic and can be used in any digital services scenario, from developing next-generation IT systems to enabling IoT services and smart cities, or onboarding virtual network functions. The interfaces are REST-based and can be used by almost any programming language.

They are developed using a crowdsourcing approach, and members are encouraged to contribute extensions and enhancements for the benefit of everyone who uses them. The Open APIs also are easy to test, and TM Forum offers formal conformance certification and Vodafone have been joined by dozens more CSPs and suppliers pushing for the Open APIs to become the de facto standard in the telecoms industry.

It has not been an easy sell with every company. Most CSPs and suppliers have invested heavily in developing their own APIs, and the value of adopting an industry standard is not always readily apparent to everyone working inside a company, especially during ongoing IT transformation when teams are able to implement workarounds such as API gateways and “wrappers” for existing APIs.

But as understanding grows about how industry fragmentation impedes innovation and the ability to compete, so does adoption of the Open APIs. Today, most of the world’s largest CSPs and telecoms suppliers are pledging their support not only for the interfaces, but even more importantly the Open Digital Architecture (ODA). (Logos of the companies supporting the Open APIs and ODA are shown in the image below.)

Today, TM Forum provides more than 50 Open APIs that CSPs and others can use for IT transformation and end-to-end management of complex digital services. Over 22,000 people from 1,900 companies are using the interfaces. In 2020 alone, 886 companies downloaded 106,300 API assets.

To date, 75 companies – 18 of the world’s leading CSPs and 57 of their suppliers and other partners – have signed the Open API Manifesto publicly demonstrating their endorsement of the Open APIs. In signing the manifesto, CSPs agree to position the Open APIs as a requirement in their IT requests for proposal and other methods of procurement such as proofs of concept and hackathons. Their supplier partners commit to using Open APIs in relevant product applications and to provide feedback and extensions to the APIs.

A combined Open API and Open Digital Architecture Manifesto is supported by 44 companies, including 15 global service providers. The ODA is a framework under development which aims to create a software marketplace where CSPs can easily procure Lego-like IT components in order to speed innovation, improve customer experience and reduce costs.

The idea is to define standardized, interoperable and reusable software components that are organized loosely into coupled domains. The components expose business services through the Open APIs, which are built on a common data model. Importantly, ODA provides machine-readable assets and software code, including a reference implementation and test environment, which is the first step toward a viable marketplace.