Recreation Information Database
Recreational areas, federal lands, historic sites, museums, and other attractions/resources(US)
UK company data: profiles, directors, PSC, iXBRL-parsed financials, ECCTA status.
Registrum API is a free Open Data API that requires apiKey authentication, is served over HTTPS and does not support CORS, so it should be called from a server.
Details from api.registrum.co.uk.

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Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Recreational areas, federal lands, historic sites, museums, and other attractions/resources(US)
Consumer product-safety recall notices from 11 government registers, looked up by barcode (EAN/GTIN)
The Registrum API is provided by Registrum API (api.registrum.co.uk).
Yes. The Registrum API is listed in the Open Data 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.
Yes. The Registrum API uses apiKey authentication, so you need to register for credentials before making requests.
Not directly. The Registrum API does not allow CORS, so call it from a server, serverless function or proxy instead of front-end JavaScript.
Yes. The Registrum API is served over HTTPS, so it's safe to use in production.