/opencitations/citations

POST /api/opencitations/citations

Price: 1 credit

Get one citation link by its Open Citation Identifier: the identifiers of the citing and cited work, the date the citing work appeared, the interval between the two publications, and whether the pair is a journal or author self-citation

How to use it

An OCI is the two OpenCitations Meta numbers of the citing and cited work joined by a dash, so it comes from an edge returned by /opencitations/works/citations or /opencitations/works/references rather than from anything a paper carries. Use this to re-read one known link; to ask whether A cites B without holding the OCI, list one side's edges instead.

Parameters

• access-token string required

Request body

• timeout integer — Max scrapping execution timeout (in seconds) (default: 300; min: 20; max: 1500)
• oci string required — Open Citation Identifier of the citation link, the two dash-separated numbers a citation edge carries as `oci` (examples: "0629059472-06120344846"; minLength: 1)

Response

• @type string (default: "OpenCitationsCitation")
• oci string required
• citing object nullable
  • @type string (default: "OpenCitationsWorkRef")
  • omid string nullable
  • doi string nullable
  • pmid string nullable
  • pmcid string nullable
  • openalex string nullable
  • other_ids array (default: [])
• cited object nullable
  • @type string (default: "OpenCitationsWorkRef")
  • omid string nullable
  • doi string nullable
  • pmid string nullable
  • pmcid string nullable
  • openalex string nullable
  • other_ids array (default: [])
• creation_date string nullable
• timespan string nullable
• is_journal_self_citation boolean nullable
• is_author_self_citation boolean nullable

Errors

• 422 — The request body did not validate Check the fields against this schema. A URN with the wrong prefix is the most common cause.
• 408 — The request ran past its time limit Raise `timeout` in the request body, up to the maximum this endpoint documents. Lowering `count` or turning off the `with_*` flags also helps, because less work finishes sooner.
• 412 — The index holds no citation with this OCI Retrying will not help: either the entity does not exist, or the input points at a different one.
• 429 — Too many requests: a rate limit or a usage window is exhausted When the response carries an X-Retry-After header, wait that many seconds and retry: the same number is in the body as `detail.retry_after`, and the limit clears once that window passes. The message in the body names the limit that was hit.
• 500 — Something broke on our side Retrying will not help. If it keeps happening, send us the X-Request-ID from the response headers.
• 529 — Rate limit reached, or the endpoint is overloaded Wait at least 30 seconds, then retry.

Response headers

• X-Error — Error message text (present only on error)
• X-Request-ID — Unique request identifier
• X-Execution-Time — Execution time in seconds
• X-Result-Count — How many records the body carries. 0 means an empty result, which is a normal answer and not by itself an error. A non-zero count can come back together with X-Error when the failure happened partway through — read this header and X-Error independently.
• X-Total-Available-Results — How many records exist for this query, when the endpoint can say. On a `dry_run` request this is the answer and the body is empty. It saturates: the endpoint's documented maximum means 'at least that many', any smaller number is exact.
• X-Warning — Present when the request body carried keys this endpoint does not document. They were ignored, so any filter you meant to apply through them did not apply. Check the spelling against this schema and retry.
• X-Retry-After — Seconds to wait before retrying. Present only on 429.