Repository: public-apis/public-apis
What public-apis actually is
public-apis is a community-curated directory of free and public APIs, maintained by contributors together with staff at APILayer. It is not a library, SDK, or gateway: there is no package to import and nothing to run in production. The repository is essentially one very large, structured README that catalogs APIs across roughly fifty categories, from Animals and Anime to Finance, Machine Learning, Security, and Weather. Each entry is a row in a table with five columns: the API, a short description, the authentication model (apiKey, OAuth, or none), whether it serves over HTTPS, and whether it sets permissive CORS headers. That last detail is the part most engineers undervalue.
Why engineers keep coming back to it
The star count, now past 438,000, is less interesting than the metadata discipline. When you are prototyping and need a currency-exchange or geocoding endpoint, the Auth/HTTPS/CORS columns let you filter candidates before you ever open a browser tab. "No auth, HTTPS yes, CORS yes" tells you that you can call the endpoint directly from a front-end spike without standing up a proxy or registering for a key. For throwaway demos, hackathons, internal tools, and teaching material, that triage saves real time. The category index doubles as a map of what kinds of public data are actually available, which helps when you are scoping whether an idea is even feasible.
