{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://caugi.org/schemas/caugi-v1.schema.json",
  "title": "Caugi Graph Format",
  "description": "JSON schema for causal graph serialization format version 1",
  "type": "object",
  "required": [
    "format",
    "version",
    "graph"
  ],
  "properties": {
    "format": {
      "type": "string",
      "const": "caugi",
      "description": "Format identifier, must be 'caugi'"
    },
    "version": {
      "type": "string",
      "pattern": "^1\\.\\d+\\.\\d+$",
      "description": "Schema version (semantic versioning: 1.x.x)"
    },
    "graph": {
      "type": "object",
      "required": [
        "class",
        "nodes",
        "edges"
      ],
      "properties": {
        "class": {
          "type": "string",
          "enum": [
            "DAG",
            "PDAG",
            "ADMG",
            "UG",
            "UNKNOWN"
          ],
          "description": "Graph class/type"
        },
        "nodes": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "uniqueItems": true,
          "description": "Array of unique node names"
        },
        "edges": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "from",
              "to",
              "edge"
            ],
            "properties": {
              "from": {
                "type": "string",
                "description": "Source node name"
              },
              "to": {
                "type": "string",
                "description": "Target node name"
              },
              "edge": {
                "type": "string",
                "description": "Edge type using DSL operator (e.g., '-->', '<->', '---', 'o->', '--o', 'o-o')"
              }
            },
            "additionalProperties": false
          },
          "description": "Array of edges between nodes"
        }
      },
      "additionalProperties": false
    },
    "meta": {
      "type": "object",
      "properties": {
        "comment": {
          "type": "string",
          "description": "Optional comment describing the graph"
        },
        "tags": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "Optional tags for categorizing the graph"
        }
      },
      "additionalProperties": false
    }
  },
  "additionalProperties": false
}