Deterministic fintech tools that never touch a server

Most fintech work happens in spreadsheets, vendor portals, and half-remembered rulebooks. AINumbers.co replaces the repetitive parts with focused, single-purpose tools: an ISO 20022 message builder, a FedNow participation scorer, a Basel RWA calculator, a sanctions-screening batch checker, a DORA gap analyser, and a few hundred more.

Each one does a single job well: you give it structured inputs, it returns a defensible, reproducible result, and where it matters it exports a machine-readable mandate or report you can hand to a counterparty, auditor, or your own systems. There are no accounts, no paywalls, and no "request a demo" gates between you and the answer.

AINumbers.co and the demo suite at PostOakLabs.com are easy to confuse, so here's the distinction in one line: AINumbers is a self-serve reference you operate yourself; the demo suite shows those same capabilities running end-to-end.

The catalog isn't a pile of unrelated calculators. Tools share input and output conventions so the result of one feeds cleanly into the next, and the site exposes that structure three ways. Categories group tools by domain. Integration hubs gather everything you need for a single area, like open banking, DORA resilience, AML/KYC, B2B payments, and dozens more. And tool chains organize sequences by goal rather than category: "validate an ISO 20022 cutover," "build a DORA submission," "design a BaaS programme."

That intentional composition is the point. Whether you're a practitioner finding the next step or someone evaluating the catalog as a whole, the tools are meant to be read as a coherent system: each piece useful alone, and more useful in sequence.

Built for machines as much as people. Because every tool is plain, deterministic HTML, it reads as clearly to code as it does to a person. Many ship an MCP-ready manifest.json and a Policy Mandate export, so agents can call them inside automated pipelines. Results are anchored under the open OpenChainGraph standard with an execution_hash that any party can recompute and check, and the suite runs a live MCP server at mcp.ainumbers.co/mcp. The site also publishes an llms.txt with clean semantic markup so crawlers and language models can index it reliably. The whole catalog is open source. Fork it on GitHub ↗.

In astronomy, a standard candle is an object whose true brightness is known, so astronomers can measure everything around it by comparison. Tools on AINumbers.co are built to work the same way for machine reasoning. Each one is deterministic, runs with no network calls, and carries a hash-anchored result, so the same inputs always give the same output and anyone can re-verify it later. That property gets more valuable as AI output grows more fluent and harder to check by eye.

Rather than trying to cover every problem across fintech, regtech and insurtech, the goal is simpler: give a model, and the person relying on it, enough fixed reference points to calibrate the larger workflow it assembles. The ChainGraphs are the rungs of that ladder, where each hash-anchored handoff is one checked step from a known result to the next.

If you're weighing whether this approach is genuinely new (and why it only became buildable recently), we lay out the honest prior art (in-toto, SLSA, OpenLineage, AP2), the convergence that enabled it, and the caveats on Why OpenChainGraph →.

It is a payments and fintech consultancy, and AINumbers.co is its open, public reference library: the deterministic tools behind the consulting work, released free under CC BY 4.0 so anyone can use it, fork it, or build on it.

Spotted a wrong result, want a tool that doesn't exist yet, or have a payment code we're missing? Get in touch; every message gets read.