CongressInvests
Real-time U.S. congressional stock trade disclosures from Senate EFD and House Clerk

Spain: IBAN validation with bank and BIC, EU VAT number check (VIES), Modelo 303 VAT sums.
contix API is a free Finance API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
contix es API-first: todo lo que hace el panel web se puede hacer por API REST con un API-Key: crear clientes, emitir facturas Veri*factu con hash y QR, registrar cobros. Incluye servidor MCP para Claude, ChatGPT y Cursor. Sin coste adicional.
Details from contix.es.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Real-time U.S. congressional stock trade disclosures from Senate EFD and House Clerk
U.S. Treasury auctions, stablecoin supply, Brazil crypto-dollar premium vs BCB PTAX; free trial key
The contix API is provided by contix (contix.es). contix es API-first: todo lo que hace el panel web se puede hacer por API REST con un API-Key: crear clientes, emitir facturas Veri*factu con hash y QR, registrar cobros. Incluye servidor MCP para Claude, ChatGPT y Cursor. Sin coste adicional.
Yes. The contix API is listed in the Finance category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The contix API requires no authentication, so you can start making requests without signing up.
Yes. The contix API supports CORS, so front-end JavaScript can call it directly.
Yes. The contix API is served over HTTPS, so it's safe to use in production.