arcsecond.io vs inspirehep.net

Arcsecond.io is the cloud API behind Arcsecond.local, a multi-user platform observatories run to manage telescopes, night logs, and data packages, but it still exposes the project's original public astronomy-lookup endpoints for object coordinates and exoplanets. Those endpoints are keyless and return live-synced records — /exoplanets/ pulls current rows from the NASA Exoplanet Archive. Paid tiers apply only to running a private observatory instance; the public data-lookup endpoints stay free.

INSPIRE-HEP is the high-energy physics community's literature database, covering papers, authors, institutions, and citation graphs going back decades. Its REST API returns JSON records for literature, author, and conference searches and is fully keyless, with no registration or rate-limit tier to opt into.