We think payment errors are a documentation problem.
Most payment failures aren't fraud, they're friction: an endpoint nobody explained properly, an error code with no plain-English meaning, a webhook that fires twice and nobody warned you. Ledgerline exists to remove that friction from the API itself.
What we build
A single, typed API for moving money: charges, refunds, payouts, and the webhooks that keep your system in sync with ours. No dashboard you have to reverse-engineer, no SDK that hides what's actually happening on the wire.
How we work
Every endpoint ships with the request that created it. When we change a response shape, the old shape keeps working behind a version header for at least eighteen months, and we tell you why we changed it, not just that we did.
Charges processed last year
38M+
Median API response time
94ms
Engineers on integration support
12
Who's behind it
A small, distributed team of people who have shipped payments integrations badly enough, at other jobs, to know exactly what they wished existed. We review every public API change as a group before it ships.
What we optimise for
Not features. Legibility. If a new endpoint needs three paragraphs to explain, we usually redesign the endpoint instead of writing the paragraphs.
How this site was built
Ledgerline is an alias: the client's real name has been substituted here to protect their privacy. The brief was a payments API site that feels as precise as the requests it documents, with a live request typing out in the first screen and nothing standing between a developer and the code they are about to run.
It's a Next.js App Router site written in TypeScript, styled with Tailwind, with no component library and no animation library. The travelling gradient borders, the beam grid behind the hero and the typing code panel are hand-built CSS and a few small client components.
The pricing, the company names in the "running on" strip and the metrics on this page stand in for the client's own figures, which stay private, and the endpoints in the code samples use the alias domain. If you'd like to see the actual work behind this, or talk about a real project, the links below go to us directly.
By Fuchan Studios · Website · GitHub · X · Instagram · Email