API reference
This URL is a redirect. The API reference is at /api.html.
Why this page exists: the documentation build generates navigation that links to
api/index.html, but the generated site contains no such file, so that
link returned 404 on every page that used it. Adding this single page makes the
existing link resolve. The alternative would have been to rewrite the generated
pages, which was avoided on purpose: a delivery referencing this site is under
review, and its files are kept byte-identical while that is pending.
The underlying generator behaviour is worth an upstream report.