Anime discovery platform.
Kitsu API is a free Anime API that requires OAuth authentication, is served over HTTPS and supports CORS, so it can be called from the browser.

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Yes. The Kitsu API is listed in the Anime 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 Kitsu API uses OAuth authentication, so you need to register for credentials before making requests.
Yes. The Kitsu API supports CORS, so front-end JavaScript can call it directly.
Yes. The Kitsu API is served over HTTPS, so it's safe to use in production.