Endpoint catalogue & notes

Code snippets

curl "https://api.oanor.com/opencitations-api/v1/meta" \
  -H "x-oanor-key: oanor_test_..."

await fetch("https://api.oanor.com/opencitations-api/v1/meta", {
  headers: { "x-oanor-key": "oanor_test_..." }
});

$ch = curl_init("https://api.oanor.com/opencitations-api/v1/meta");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);

import requests
requests.get(
    "https://api.oanor.com/opencitations-api/v1/meta",
    headers={"x-oanor-key": "oanor_test_..."}
)

Example response

A real response from this endpoint, captured by the latest health check.

{
    "data": {
        "note": "OpenCitations publishes scholarly citations as open data — each citation is a first-class object with its own OpenCitations Identifier (OCI), the citing and cited DOI, the date the citation was created, the timespan between the two works and whether it is a journal- or author-self-citation. /v1/citations?doi=10.1186/1756-8722-6-59 = the papers that CITE this DOI (incoming citations), each with citing DOI, OCI, creation date, timespan and self-citation flags; /v1/references?doi=10.1186/1756-8722-6-59 = the papers this DOI REFERENCES (outgoing), in the same shape; /v1/count?doi=10.1186/1756-8722-6-59 = the citation count (how often it is cited) and reference count (how many works it cites). Pass any DOI as doi=10.xxxx/yyyy (limit 1-200 on the lists; timespan is an ISO-8601 duration like P0Y0M11D). Data from OpenCitations (CC0). A citation-network / bibliometrics tool — incoming citations, self-citation detection and citation timespan, distinct from scholarly-metadata lookups (Crossref, OpenAlex). Ideal for bibliometrics, research-impact, science-mapping and reference-management tools.",
        "source": "OpenCitations — the open citation index, COCI (opencitations.net)",
        "endpoints": [
            "/v1/citations",
            "/v1/references",
            "/v1/count",
            "/v1/meta"
        ]
    },
    "meta": {
        "timestamp": "2026-06-01T16:23:10.603Z",
        "request_id": "19d1c43c-79b7-442a-9844-90227fe193ca"
    },
    "status": "ok",
    "message": "Meta retrieved",
    "success": true
}