{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://w3id.org/em/schemas/em.v1.schema.json",
  "$comment": "PUBLISHED COPY. Source of truth: https://github.com/ExtendedMatrix/s3Dgraphy, spec/em-json/em.v1.schema.json, commit 8209cab. Do not edit it here: edit it there and republish (spec/em-json/tools/publish_site.py), or the two drift apart.",
  "title": ".em.json v1 (FROZEN 2026-07-11)",
  "description": "Extended Matrix native document: header + FLAT graph (nodes[]/edges[]) + optional layout. Reference implementation: s3Dgraphy emjson_exporter/emjson_importer. Consumers MUST ignore unknown top-level keys.",
  "type": "object",
  "required": [
    "header",
    "graph"
  ],
  "properties": {
    "header": {
      "type": "object",
      "required": [
        "format",
        "version"
      ],
      "properties": {
        "format": {
          "const": "em.json"
        },
        "version": {
          "type": "string",
          "pattern": "^1\\."
        },
        "generator": {
          "type": "object",
          "properties": {
            "tool": {
              "type": "string"
            },
            "version": {
              "type": "string"
            }
          }
        },
        "datamodel_versions": {
          "type": "object",
          "additionalProperties": {
            "type": "string"
          }
        },
        "ontology_versions": {
          "type": "object"
        }
      }
    },
    "graph": {
      "type": "object",
      "required": [
        "graph_id",
        "nodes",
        "edges"
      ],
      "properties": {
        "graph_id": {
          "type": "string"
        },
        "code": {
          "type": "string",
          "description": "The study's code (GT16), a mirror of StudyNode.data.code written at every save; the study wins on read."
        },
        "code_proposed": {
          "type": "boolean",
          "description": "Present (true) while the code is a proposal nobody confirmed."
        },
        "name": {
          "type": "string"
        },
        "description": {
          "type": "string"
        },
        "data": {
          "type": "object"
        },
        "nodes": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "id",
              "node_type"
            ],
            "properties": {
              "id": {
                "type": "string"
              },
              "node_type": {
                "type": "string"
              },
              "name": {
                "type": "string"
              },
              "description": {
                "type": "string"
              },
              "data": {
                "type": "object"
              }
            }
          }
        },
        "edges": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "id",
              "edge_type",
              "source",
              "target"
            ],
            "properties": {
              "id": {
                "type": "string"
              },
              "edge_type": {
                "type": "string"
              },
              "source": {
                "type": "string"
              },
              "target": {
                "type": "string"
              }
            }
          }
        }
      }
    },
    "layout": {
      "type": "object",
      "properties": {
        "canvas": {
          "type": "object",
          "properties": {
            "title": {
              "type": "string"
            },
            "width": {
              "type": "number"
            },
            "height": {
              "type": "number"
            }
          }
        },
        "swimlanes": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "epoch_id",
              "order"
            ],
            "properties": {
              "epoch_id": {
                "type": "string"
              },
              "order": {
                "type": "integer"
              },
              "y": {
                "type": "number"
              },
              "height": {
                "type": "number"
              }
            }
          }
        },
        "sectors": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "id",
              "order"
            ],
            "properties": {
              "id": {
                "type": "string"
              },
              "order": {
                "type": "integer"
              },
              "x": {
                "type": "number"
              },
              "width": {
                "type": "number"
              }
            }
          }
        },
        "positions": {
          "type": "object",
          "additionalProperties": {
            "type": "object",
            "required": [
              "x",
              "y"
            ],
            "properties": {
              "x": {
                "type": "number"
              },
              "y": {
                "type": "number"
              },
              "w": {
                "type": "number"
              },
              "h": {
                "type": "number"
              }
            }
          }
        },
        "folded_groups": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "group_spaces": {
          "type": "object",
          "additionalProperties": {
            "type": "object",
            "properties": {
              "positions": {
                "$ref": "#/properties/layout/properties/positions"
              }
            }
          }
        },
        "edge_routes": {
          "type": "object",
          "additionalProperties": {
            "type": "array",
            "items": {
              "type": "array",
              "prefixItems": [
                {
                  "type": "number"
                },
                {
                  "type": "number"
                }
              ]
            }
          }
        }
      }
    }
  }
}