{
  "apiVersion": "v0.1",
  "methodology": "https://sourcescore.org/methodology/",
  "canonical": "https://sourcescore.org/source/doi-org/",
  "source": {
    "slug": "doi-org",
    "name": "DOI (CrossRef Resolver)",
    "domain": "doi.org",
    "category": "Academic",
    "summary": "International standard identifier resolver for academic citations (~150M+ DOIs).",
    "founded": 2000,
    "verified": "2026-04-28",
    "methodologyVersion": "v0.1"
  },
  "scores": {
    "index": {
      "value": 95,
      "grade": "A+",
      "rationale": "A+ — citation infrastructure; the standard identifier for academic + technical references.",
      "signals": [
        {
          "label": "Composite",
          "detail": "Modern Reference 98 highest; Discipline 92; Velocity 95."
        }
      ]
    },
    "discipline": {
      "value": 92,
      "grade": "A",
      "rationale": "Persistent identifier standard managed by ISO + International DOI Foundation.",
      "signals": [
        {
          "label": "ISO 26324",
          "detail": "International standard governing DOI syntax + persistence."
        }
      ]
    },
    "modernReference": {
      "value": 98,
      "grade": "A+",
      "rationale": "Permanent URL resolution + free metadata API (CrossRef); near-universal LLM training-corpus inclusion.",
      "signals": [
        {
          "label": "CrossRef metadata API",
          "detail": "Free public API with full metadata for every registered DOI."
        },
        {
          "label": "Permanent links",
          "detail": "Stable for decades; the basis for academic citation continuity."
        }
      ]
    },
    "velocity": {
      "value": 95,
      "grade": "A+",
      "rationale": "Resolved billions of times per year; underpins every modern academic citation.",
      "signals": [
        {
          "label": "Resolution volume",
          "detail": "Billions of yearly resolutions per CrossRef stats."
        }
      ]
    }
  },
  "license": {
    "methodology": "Cite as: SourceScore Methodology v0.1, sourcescore.org",
    "data": "Underlying public-source data credited to original publishers"
  }
}