HAL — ENPC Open-Access Collection (tenant)
ENPC's institutional open-access repository is the ENPC collection inside HAL, the French national open archive operated by CCSD/CNRS, with an ENPC-branded portal at enpc.hal.science. 43,955 records, 31,437 of them carrying author ORCID iDs. Machine access exists in two forms, both on CCSD's shared national host and scoped to ENPC by path or set selector: the Solr search API at api.archives-ouvertes.fr/search/ENPC/ and the OAI-PMH 2.0 provider with set=collection:ENPC. Recorded as ONE tenant relationship, not as separate APIs: api.archives-ouvertes.fr is generic national infrastructure shared by every French research institution and its contract is CCSD's, not ENPC's. The portal host answers 200 with an Anubis bot challenge.