{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://kb.local/wire/v1/answer.schema.json",
  "title": "Answer v1",
  "description": "Stub schema — declares the schema_version label and the required fields per design §2.3.",
  "type": "object",
  "required": [
    "schema_version",
    "answer",
    "citations",
    "grounded",
    "model",
    "prompt_template_version",
    "retrieval",
    "usage",
    "created_at"
  ],
  "properties": {
    "schema_version":          { "const": "answer.v1" },
    "answer":                  { "type": "string" },
    "citations":               { "type": "array" },
    "grounded":                { "type": "boolean" },
    "refusal_reason":          { "type": ["string", "null"] },
    "model":                   { "type": "object" },
    "embedding":               { "type": ["object", "null"] },
    "prompt_template_version": { "type": "string" },
    "retrieval":               { "type": "object" },
    "usage":                   { "type": "object" },
    "created_at":              { "type": "string", "format": "date-time" },
    "conversation_id":         {
      "type": ["string", "null"],
      "description": "p9-fb-15: same conversation 의 turn 들이 공유. CLI single-shot / TUI 첫 turn 은 null."
    },
    "turn_index":              {
      "type": ["integer", "null"],
      "minimum": 0,
      "description": "p9-fb-15: 같은 conversation 안 0-based 순서. null 이면 single-shot."
    }
  }
}