
High Energy Physics info. system.
inspirehep.net API is a free Science & Math API that requires no API key, is served over HTTPS and has unconfirmed CORS support.
Documentation of the INSPIRE REST API.
Details from github.com.

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ISRO Space Crafts Information
The inspirehep.net API is provided by inspirehep (github.com). Documentation of the INSPIRE REST API.
Yes. The inspirehep.net API is listed in the Science & Math 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 inspirehep.net API requires no authentication, so you can start making requests without signing up.
CORS support for the inspirehep.net API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The inspirehep.net API is served over HTTPS, so it's safe to use in production.