Why we built oneapi.finance
After paying $99/mo for a markets API on a portfolio tracker that hadn't yet made a euro, we did the obvious thing — we built the cheaper one.
The bill that started it
In December 2023 our portfolio tracker side-project was paying $99 a month for markets data. The tracker had 47 weekly active users at the time. The math, if you squinted, said we were paying roughly $2.10 per user per month for data, on an app that earned $0 in revenue.
We could have shut the project down. Instead we did the obvious thing. We spent six weeks reading exchange data licensing pages, three weeks prototyping the gateway, four weeks negotiating two upstream contracts, and a weekend writing this landing page.
What’s wrong with the existing options
The markets-data market is shaped like a barbell. On one end you have the budget incumbent at $29/mo with restrictive caps and no fundamentals on the entry tier. On the other end you have legacy providers starting at $199–$499/mo and a sales call to even see prices. There is no middle.
That’s strange because the middle is where every indie dev sits. We need fundamentals (every portfolio tracker does). We need 70+ exchanges (retail investors hold European ETFs and US stocks in the same account). We need predictable EUR pricing (because we are Europeans). We need a free tier that lets us ship before paying.
Nobody serves the middle, so we are.
What we built
A gateway in front of normalized markets data, priced in EUR, on a soft-cap plan that emails you before it bills you. €19/mo includes intraday (15-min delayed), fundamentals, dividends, news, and corporate actions — all the things every portfolio tracker actually needs. The free tier is 800 requests per day, no card.
We are explicit about what we don’t sell: tick-level data, options Greeks, Level-2 books, satellite imagery. If you need those, you are not our customer, and we will say so before you sign up.
Building in public
We will publish a quarterly metrics post with ARR, gross margin, and infra cost. The first one drops in July 2026. Our roadmap lives on GitHub. If you are also building an indie API and want to compare notes, our DMs are open.
The whole reason we built this thing is to be the kind of provider we wished we had as customers. That includes being legible — about prices, about scope, about when we screw up. We will, occasionally, screw up. When we do, the post-mortem goes here.
— Sam