
Dated historical events as JSON, each quoted from a cited Wikipedia revision.
SlashYear API is a free Open Data API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Free, static, CORS-open JSON for every year, day, subject and timeline; the whole corpus as a gzipped download; and an MCP server for models. No key, no rate limit, no signup.
Details from slashyear.com.

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The SlashYear API is provided by slashyear (slashyear.com). Free, static, CORS-open JSON for every year, day, subject and timeline; the whole corpus as a gzipped download; and an MCP server for models. No key, no rate limit, no signup.
Yes. The SlashYear 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.
No. The SlashYear API requires no authentication, so you can start making requests without signing up.
Yes. The SlashYear API supports CORS, so front-end JavaScript can call it directly.
Yes. The SlashYear API is served over HTTPS, so it's safe to use in production.