Stop reinventing financial validation in TypeScript

If you've worked on a payment product, a banking app, or anything involving money, you've written this code before. An IBAN validator you copied from Stack Overflow. A Luhn check for card numbers someone found in a gist. A currency formatter that works in en-US but breaks for de-DE. A sort code regex that someone on the team "maintains." A loan calculator buried in a utility file no one touches. Every fintech team builds this stuff. Then rebuilds it. Then inherits the third version and tries to figure out why it exists. I built finprim to fix this. What finprim is finprim is a zero-dependency TypeScript library that handles the financial primitives every app needs: IBAN validation (80+ countries) and formatting BIC/SWIFT validation UK sort code and account number validation Card number validation (Luhn algorithm + network detection) EU VAT number validation US ABA routing number validation Loan/EMI calculations with full amortization schedules Multi-locale currency formatting and parsi