Links entities extracted by OpenMed to UMLS Metathesaurus CUIs using the USER'S OWN UTS API key, with nothing from the Metathesaurus bundled or cached. Use when the user wants to normalize concepts across vocabularies to a single CUI, resolve synonyms via the UMLS, filter by semantic type, or cross-walk between SNOMED CT, ICD-10, RxNorm and MeSH through their shared CUI. Trigger keywords: UMLS, CUI, Metathesaurus, UTS API key, semantic type, TUI, MetaMap, QuickUMLS, concept normalization, cross-vocabulary. Pairs after OpenMed NER: consume Disease/Pharmaceutical/Chemical/Anatomy entities from openmed.analyze_text and resolve each span to a CUI out-of-process. UMLS is license-restricted — the Metathesaurus is NEVER bundled; every call uses the user's UTS account.