#ontology

The EMBL-EBI Ontology Lookup Service (OLS) as an API — a single access point to more than 280 biomedical and scientific ontologies and controlled vocabularies in one place: the Gene Ontology (GO), the Human Disease Ontology (DOID), the Human Phenotype Ontology (HP), ChEBI (chemical entities), Uberon (anatomy), the Experimental Factor Ontology (EFO), Mondo, NCIt and many more. /v1/search?q=diabetes searches terms across all ontologies (or restrict to one with ontology=doid), returning each match's label, OBO id (such as DOID:9351 or GO:0008150), ontology, IRI and a short definition. /v1/term?ontology=doid&id=DOID:9351 returns a single term's detail — its label, definition, IRI, synonyms and whether it is obsolete. /v1/ontologies browses the available ontologies with their id, title, description and number of terms. OBO ids look like DOID:9351, GO:0008150, HP:0000118 or CHEBI:15377. Ideal for biomedical natural-language processing, data annotation and harmonisation, autocomplete over scientific terminology, and semantic and knowledge-graph tooling. Data from EMBL-EBI OLS (open). This is a general ontology / controlled-vocabulary lookup spanning many domains — broader than a single medical thesaurus such as MeSH.

api.oanor.com/ols-api

Medical Subject Headings (MeSH) as an API, powered by the U.S. National Library of Medicine's official MeSH RDF service. MeSH is the NLM's authoritative controlled vocabulary used to index the biomedical literature in PubMed — a curated thesaurus of diseases, anatomy, chemicals and drugs, organisms, psychiatry and psychology, analytical and diagnostic techniques, health care and more. Each concept is a "descriptor" with a stable unique id (e.g. D003920), a preferred name, a set of entry terms (synonyms and lay variants), and a list of allowable qualifiers (subheadings such as drug therapy, diagnosis or epidemiology). /v1/search?q=diabetes searches descriptors by their preferred name (match=contains, exact or startswith) and returns each descriptor's id and label. /v1/term?q=heart attack resolves a lay term or synonym to the MeSH descriptor(s) it belongs to, so colloquial language maps onto the controlled vocabulary (heart attack to Myocardial Infarction). /v1/descriptor?id=D003920 returns a descriptor's full record — its preferred name, all entry terms (synonyms), the allowable qualifiers and see-also cross-references, with a link to the MeSH browser. Ideal for biomedical natural-language processing and text mining, tagging and indexing literature, building clinical and research search tools, autocomplete over medical terminology, and mapping free text onto a standard ontology. Data from NLM MeSH (public domain). For drug-specific clinical nomenclature and interactions, see the RxNorm API.

api.oanor.com/mesh-api

Biomedical ontologies as an API, powered by the EBI Ontology Lookup Service (OLS). Search across 280+ curated ontologies — diseases (MONDO), human phenotypes (HP), the Gene Ontology (GO), anatomy (UBERON), cell types (CL), chemistry (ChEBI), experimental factors (EFO), the NCI Thesaurus and many more — to find terms by name; browse the full ontology catalogue with versions and term counts; read any term for its definition, exact synonyms, OBO id, IRI and obsolete status; and walk the class hierarchy through a term's direct parents and children. Ideal for clinical-data harmonisation and coding, biomedical search and autocomplete, knowledge-graph enrichment, annotation and curation pipelines, and research and EHR applications that need standard vocabularies. OBO ids look like MONDO:0005148 or GO:0008150.

api.oanor.com/ontology-api