The file must have three keys: meta (title & subtitle), nodes (array of node objects with label, type, r, desc) and links (array of edges with source, target, type).

{
  "meta": {
    "title": "My Graph",
    "subtitle": "A short description · Author"
  },
  "nodes": [
    { "label": "Concept A", "type": "concept",  "r": 22, "desc": "A core concept node." },
    { "label": "Method B",  "type": "method",   "r": 16, "desc": "A method or paradigm." },
    { "label": "Finding C", "type": "finding",  "r": 14, "desc": "An empirical observation." }
  ],
  "links": [
    { "source": "Concept A", "target": "Method B",  "type": "enables"  },
    { "source": "Method B",  "target": "Finding C", "type": "produces" }
  ]
}