License URL catalog (26,945 entries)

GET

/api/v1/research/crossref/license-catalog

Last modified:2026-05-10 09:22:39

Maintainer:Not configured

OperationId:research_crossref_license_catalog

Return the aggregated license-URL catalog - the distinct set of license URLs that publishers have deposited across the Crossref corpus. Each entry carries the URL and the count of works depositing that exact URL. Useful for analytics of open-access licensing distribution. Values vary in casing and normalisation because Crossref preserves publisher-supplied strings. The catalog shifts slowly; Sugra caches for 7 days. Data licensed CC0 by Crossref.

Request

Authorization

API Key

Add parameter in header

x-api-key

Example:

x-api-key: ********************

Query Params

Header Params

Request Code Samples

Shell

JavaScript

Java

Swift

PHP

Python

HTTP

Objective-C

Ruby

OCaml

Dart

Responses

🟢200

application/json

License URL entries with work counts, plus pagination block.

Bodyapplication/json

Example

{
    "data": {
        "items": [
            {
                "URL": "string",
                "work-count": 0
            }
        ],
        "list_meta": {
            "total_results": 0,
            "items_per_page": 0,
            "next_cursor": "string"
        }
    },
    "meta": {
        "endpoint": "/api/v1/fred/us/cpi",
        "data_time": "2026-04-16T14:30:00Z",
        "response_time": "2026-04-16T14:30:12Z",
        "provider": "Sugra API v1.0.1",
        "source": "string",
        "fallback_used": true,
        "fallback_chain": [
            "string"
        ],
        "cached": true
    }
}

🟠401

🟠422

🟠429

🔴503

Modified at 2026-05-10 09:22:39

Publication-type catalog (30 stable entries)

References cited by a DOI