{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Knotviz Graph",
  "description": "A graph data file for the Knotviz visualizer. Contains versioned node and edge definitions with optional properties for visualization and analysis.",
  "type": "object",
  "required": ["version", "nodes", "edges"],
  "additionalProperties": false,
  "properties": {
    "version": {
      "type": "string",
      "const": "1",
      "description": "Schema version. Must be \"1\"."
    },
    "nodes": {
      "type": "array",
      "description": "Array of node objects in the graph.",
      "items": {
        "type": "object",
        "required": ["id"],
        "additionalProperties": false,
        "properties": {
          "id": {
            "type": "string",
            "description": "Unique identifier for the node."
          },
          "label": {
            "type": "string",
            "description": "Display name shown on the canvas. Falls back to id if omitted."
          },
          "x": {
            "type": "number",
            "description": "Initial X position. If omitted, a random position is assigned."
          },
          "y": {
            "type": "number",
            "description": "Initial Y position. If omitted, a random position is assigned."
          },
          "properties": {
            "type": "object",
            "description": "Arbitrary key-value pairs for the node. Values can be number, string, boolean, or array of strings. ISO 8601 date strings (e.g. \"2024-01-15\") are auto-detected as dates.",
            "additionalProperties": {
              "oneOf": [
                { "type": "number" },
                { "type": "string" },
                { "type": "boolean" },
                { "type": "array", "items": { "type": "string" } }
              ]
            }
          }
        }
      }
    },
    "nodePropertiesMetadata": {
      "type": "object",
      "description": "Optional metadata for node properties. Maps property keys to objects with a description field.",
      "additionalProperties": {
        "type": "object",
        "required": ["description"],
        "additionalProperties": false,
        "properties": {
          "description": {
            "type": "string",
            "description": "Human-readable description of this property."
          }
        }
      }
    },
    "edges": {
      "type": "array",
      "description": "Array of edge objects connecting nodes.",
      "items": {
        "type": "object",
        "required": ["source", "target"],
        "additionalProperties": false,
        "properties": {
          "source": {
            "type": "string",
            "description": "ID of the source node."
          },
          "target": {
            "type": "string",
            "description": "ID of the target node."
          },
          "weight": {
            "type": "number",
            "description": "Edge weight used by the force-directed layout simulation."
          }
        }
      }
    }
  }
}