{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://hermes.bstein.dev/contracts/hux/v1/citation.schema.json",
  "title": "HUX sources, passages, citations, research notebook",
  "description": "Research model (HUX-08). A source is where evidence came from; a passage is the exact excerpt; a citation ties a claim in a message to passages with an explicit support verdict; a notebook collects them per research question with assumptions and unresolved questions kept visible.",
  "$defs": {
    "source": {
      "type": "object",
      "additionalProperties": false,
      "required": ["schema", "id", "kind", "title", "classification", "retrieved_at"],
      "properties": {
        "schema": {"const": "hux.source.v1"},
        "id": {"$ref": "common.schema.json#/$defs/id"},
        "kind": {"type": "string", "enum": ["web", "document", "artifact", "memory", "tool_output", "dataset"]},
        "uri": {"type": "string", "maxLength": 2000},
        "title": {"type": "string", "minLength": 1, "maxLength": 300},
        "publisher": {"type": "string", "maxLength": 200},
        "published_at": {"$ref": "common.schema.json#/$defs/timestamp"},
        "retrieved_at": {"$ref": "common.schema.json#/$defs/timestamp"},
        "classification": {"type": "string", "enum": ["primary", "secondary", "unknown"]},
        "content_hash": {"$ref": "common.schema.json#/$defs/sha256"},
        "provenance": {"$ref": "common.schema.json#/$defs/provenance"}
      }
    },
    "passage": {
      "type": "object",
      "additionalProperties": false,
      "required": ["schema", "id", "source_id", "text", "hash"],
      "properties": {
        "schema": {"const": "hux.passage.v1"},
        "id": {"$ref": "common.schema.json#/$defs/id"},
        "source_id": {"$ref": "common.schema.json#/$defs/id"},
        "text": {"type": "string", "minLength": 1, "maxLength": 4000},
        "hash": {"$ref": "common.schema.json#/$defs/sha256"},
        "locator": {
          "type": "object",
          "additionalProperties": false,
          "properties": {
            "page": {"type": "integer", "minimum": 1},
            "selector": {"type": "string", "maxLength": 500},
            "line_start": {"type": "integer", "minimum": 1},
            "line_end": {"type": "integer", "minimum": 1},
            "char_start": {"type": "integer", "minimum": 0},
            "char_end": {"type": "integer", "minimum": 0}
          }
        }
      }
    },
    "citation": {
      "type": "object",
      "additionalProperties": false,
      "required": ["schema", "id", "message_id", "claim", "passage_ids", "support"],
      "properties": {
        "schema": {"const": "hux.citation.v1"},
        "id": {"$ref": "common.schema.json#/$defs/id"},
        "message_id": {"type": "string", "minLength": 1, "maxLength": 120},
        "claim": {"type": "string", "minLength": 1, "maxLength": 1000},
        "passage_ids": {"type": "array", "minItems": 1, "maxItems": 32, "uniqueItems": true, "items": {"$ref": "common.schema.json#/$defs/id"}},
        "support": {"type": "string", "enum": ["supports", "partially_supports", "contradicts", "unverified"]},
        "note": {"type": "string", "maxLength": 500}
      }
    },
    "notebook": {
      "type": "object",
      "additionalProperties": false,
      "required": ["schema", "id", "conversation_id", "question", "status", "source_ids", "passage_ids", "citation_ids", "assumptions", "unresolved_questions", "updated_at"],
      "properties": {
        "schema": {"const": "hux.research_notebook.v1"},
        "id": {"$ref": "common.schema.json#/$defs/id"},
        "conversation_id": {"$ref": "common.schema.json#/$defs/id"},
        "question": {"type": "string", "minLength": 1, "maxLength": 1000},
        "status": {"type": "string", "enum": ["open", "answered", "abandoned"]},
        "source_ids": {"type": "array", "uniqueItems": true, "items": {"$ref": "common.schema.json#/$defs/id"}},
        "passage_ids": {"type": "array", "uniqueItems": true, "items": {"$ref": "common.schema.json#/$defs/id"}},
        "citation_ids": {"type": "array", "uniqueItems": true, "items": {"$ref": "common.schema.json#/$defs/id"}},
        "assumptions": {"type": "array", "maxItems": 64, "items": {"type": "string", "minLength": 1, "maxLength": 500}},
        "unresolved_questions": {"type": "array", "maxItems": 64, "items": {"type": "string", "minLength": 1, "maxLength": 500}},
        "updated_at": {"$ref": "common.schema.json#/$defs/timestamp"}
      }
    }
  },
  "oneOf": [
    {"$ref": "#/$defs/source"},
    {"$ref": "#/$defs/passage"},
    {"$ref": "#/$defs/citation"},
    {"$ref": "#/$defs/notebook"}
  ]
}