Sulu: What if Everything You Knew About Online Payments was Wrong?

An interview with Susan O'Neill, CEO and Sam Alarco, CTO of Sulu, by Joe Gorman NDRC Programme Manager.

Susan O'Neill, CEO and Sam Alarco, CTO of Sulu

If your job involves working with startups, you get pretty good at picking up acronyms and terminology and using them in sentences. Sometimes, you even learn what they mean.

Though I’ll admit it took me a while to get around the technical terms when learning about NDRC Accelerator startup Sulu, an API monetisation platform aimed at developers. The verbiage is no hindrance to the developers (or AI agents - more on that later) who will be using their platform. But I am interested to hear how CTO Sam Alarco explains his job to his mum, the postman, or someone shouting into your ear in a loud bar.

Alarco takes a deep breath: “I like to use the weather app example for people who have no idea what an API is. If you check the weather on your phone, which we do a lot in Ireland, your phone doesn’t just know the weather. Your phone needs to get that weather information from somewhere - the internet. It talks to another computer to get that information. Now, that data isn’t free - nothing’s free, right? You’re probably watching an ad on the app.”

I’m still following at this point. 

“At that point, the person is usually nodding and it all makes sense. “No problem - I have to pay for the weather data.” At Sulu, we’re the people that help companies pay for that data or monetize that data. Then the person usually says “so you move money around?,” and I can say yep, we’re the money movement platform. Then they say “okay, okay, I get it now.” I don't know if they get it completely, but at least they get it more than before.”

I’m nodding and almost catch myself saying “okay, okay, I get it now,” before we start into the actual questions. 

Alarco and CEO Susan O’Neill have a healthy glow on the video call. It’s better than anything that an Amazon ring light can bestow. The inner nosy Irishman in me comes out: “Were ye away?”

As it turns out, they had been. The pair are just back from a conference in Nashville where they met with new customers and partners, stoking the buzz around their product. 

If you check out Sulu’s API Hub, you will see a fleshed-out list of APIs that can give you access to anything from weather forecasts or global exchange rates to an API that allows you to retrieve popular memes. My personal favourite is Dog API, providing “a wealth of information on dog breeds, groups, and fun facts.” Their biggest problem now is meeting demand, onboarding the ever-growing list of suppliers that want a spot on their marketplace. How did they get to this point?

“At our core, we're a money movement platform,” says O’Neill. “Our aim is to revolutionise the monetization of data, services, and compute, but right now we’re focusing specifically on API monetization. Traditional payment rails just won’t work well and there’s a much better way to do it - that’s where we come in.”

O’Neill has always been interested in how we pay for things. “Nobody likes subscriptions, whether it’s Netflix or SaaS. It’s much easier to just pay for what you're actually using,” she says, when I ask why they focus on micropayments rather than a subscription model. “We're seeing a big move in the market generally towards pay-per-use. Stripe and OpenAI have announced usage-based billing. One of the key value propositions of our API Hub is that every API can be monetized on a usage basis.”

Does that ruffle feathers with API producers who like SaaS pricing and smooth upward curves on revenue projection graphs?

“It comes up sometimes - people like subscriptions because it's guaranteed revenue, but we’re seeing a huge push for pay-per-call or usage-based payment from the user side. For API producers, subscription pricing makes you inflexible - you can’t offer things like dynamic pricing. There are huge benefits for both parties.”

The founders are essentially micropayments evangelists who just happen to be building an API marketplace. What makes APIs interesting? O’Neill sums it up succinctly: “If you look at a heavy hitter like Stripe, they have fixed minimum payments, say 25 cent. API calls are a fraction of a cent. As a result, you actually couldn't put in an API call on a pay per use basis through Stripe because the value of the transaction is less than the fixed minimum payment. The fact that API calls are microtransactions makes them a perfect first use case.”

O’Neill and Alarco during mentoring session in the NDRC Accelerator Core Week 1

Alarco presenting Sulu’s API Marketplace to the NDRC Accelerator Cohort

O’Neill knows a thing or two about payments, cutting her teeth as an accountant and financial controller in banking, insurance, and Irish multinational Glanbia. Today she sits on the Fintech Ireland Advisory Council in addition to her full-time job building a startup. I’m interested to hear that she first met Sam Alarco on the New Frontiers programme at SETU in Waterford. 

Alarco was barking up an entirely different tree at the time, having joined the programme with his nascent computational geometry startup. But as he sat in the room and heard O’Neill’s ambitious idea pitched again and again over the six months of the programme, technical solutions were percolating in the back of his mind. 

Eventually, O’Neill approached to ask if he knew anyone in his network that might be a good CTO to lead development. Alarco put his own hand up and the build began. 

As a developer, he knew the pains of API payments “and internet native payments in general.” But the emergence of AI agents which autonomously use internet resources has been a deciding factor in how they think about the online economy. 

Startups have breakthrough moments when they know they have something special. For Alarco and O’Neill, that moment came the first time that an AI agent accessed and paid for a Sulu API endpoint autonomously in the US, and the payment settled in Europe within a matter of seconds. In those seconds, their thinking on customers changed. For O’Neill, “the main consumers of APIs on the internet in the future will be AI agents, and we are building for that future.”

O’Neill and Alarco are modest, but their end goal is not to make a niche product that developers think is cool. When O’Neill originally got in touch, she told Alarco that her ambition was to solve payments. “Anything that can be monetized on the internet is where we're moving to in the long run,” is her summation of the long term plan. 

Sulu have already raised €1.2 million through strategic angels and Enterprise Ireland. What’s next on the roadmap? O’Neill thinks for a moment: “In the next eighteen months, we think Sulu’s API Hub will be the go-to API source for developers and AI agents everywhere.”

Alarco got married in the Phillippines in February, where his in-laws grilled O’Neill about what he did for a living. She smiles: “It’s complex when you explain it at first. They just know we spend a ridiculous amount of hours every week working on something that they don't really understand. And that our ambitions are truly, absolutely massive.”

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