{
  "$schema": "../schemas/relaymark-directive.schema.json",
  "name": "Comparison",
  "ast_type": "relay.comparison",
  "version": 1,
  "category": "research",
  "description": "A structured, evidence-backed comparison of two or more referenced subjects.",
  "attributes": {
    "title": {
      "type": "string",
      "description": "Human-readable comparison title."
    },
    "subjects": {
      "type": "array",
      "items": "string",
      "required": true,
      "description": "Two or more entity or host references being compared."
    },
    "criteria": {
      "type": "array",
      "items": "string",
      "required": true,
      "description": "Ordered comparison criteria."
    },
    "values": {
      "type": "object",
      "required": true,
      "description": "Criterion-keyed JSON values for each subject."
    },
    "preferred": {
      "type": "string",
      "description": "Optional evidence-backed preferred subject reference."
    },
    "layout": {
      "type": "enum",
      "values": ["table", "bar", "timeline", "checklist", "radar", "heatmap"],
      "default": "table"
    },
    "evidence": {
      "type": "array",
      "items": "string",
      "description": "Block or source ids grounding the compared values."
    }
  },
  "children": {
    "mode": "mixed",
    "allowed_types": ["paragraph", "heading", "table", "text", "relay.entity_ref"],
    "min": 1
  },
  "validation": [
    "subjects must contain at least two distinct references",
    "criteria must contain at least one key",
    "values should provide a value or an explicit null for every subject and criterion",
    "preferred should resolve to one of subjects when present",
    "evidence refs should resolve to known blocks or source manifest entries"
  ],
  "projections": {
    "relay_kit": "Comparison",
    "html": "research-comparison",
    "plain_text": "comparison title and summary",
    "manifest": ["comparisons"]
  },
  "policy": {
    "requires_review": false,
    "requires_evidence": true,
    "allows_agent_creation": true
  }
}