{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://memabra.local/schemas/trajectory.schema.json",
  "title": "Trajectory",
  "description": "Replayable task-level trace for routing and learning in memabra.",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "trajectory_id",
    "task",
    "context_snapshot",
    "candidate_sets",
    "decisions",
    "events",
    "outcome",
    "reward"
  ],
  "properties": {
    "trajectory_id": {"type": "string", "minLength": 1},
    "task": {
      "type": "object",
      "additionalProperties": false,
      "required": ["task_id", "input", "channel", "created_at"],
      "properties": {
        "task_id": {"type": "string", "minLength": 1},
        "input": {"type": "string", "minLength": 1},
        "channel": {"type": "string", "minLength": 1},
        "created_at": {"type": "string", "format": "date-time"},
        "user_id": {"type": ["string", "null"]}
      }
    },
    "context_snapshot": {
      "type": "object",
      "additionalProperties": false,
      "required": ["conversation_summary", "environment_summary"],
      "properties": {
        "conversation_summary": {"type": "string"},
        "environment_summary": {"type": "string"},
        "recent_failures": {
          "type": "array",
          "items": {"type": "string"},
          "default": []
        }
      }
    },
    "candidate_sets": {
      "type": "object",
      "additionalProperties": false,
      "required": ["memory", "skill", "tool"],
      "properties": {
        "memory": {"type": "array", "items": {"$ref": "candidate_object.schema.json"}},
        "skill": {"type": "array", "items": {"$ref": "candidate_object.schema.json"}},
        "tool": {"type": "array", "items": {"$ref": "candidate_object.schema.json"}}
      }
    },
    "decisions": {
      "type": "array",
      "items": {
        "type": "object",
        "additionalProperties": false,
        "required": ["step", "decision_type", "selected_ids", "rationale"],
        "properties": {
          "step": {"type": "integer", "minimum": 1},
          "decision_type": {
            "type": "string",
            "enum": ["direct_answer", "inject_memory", "load_skill", "call_tool", "clarify", "composite_action"]
          },
          "selected_ids": {
            "type": "array",
            "items": {"type": "string"}
          },
          "rejected_ids": {
            "type": "array",
            "items": {"type": "string"},
            "default": []
          },
          "rationale": {"type": "string"},
          "estimated_cost": {"type": ["number", "null" ]}
        }
      }
    },
    "events": {
      "type": "array",
      "items": {"$ref": "event.schema.json"}
    },
    "outcome": {
      "type": "object",
      "additionalProperties": false,
      "required": ["status", "steps", "latency_ms", "user_corrections"],
      "properties": {
        "status": {"type": "string", "enum": ["success", "partial_success", "failure"]},
        "steps": {"type": "integer", "minimum": 0},
        "latency_ms": {"type": "integer", "minimum": 0},
        "user_corrections": {"type": "integer", "minimum": 0},
        "tool_errors": {"type": "integer", "minimum": 0},
        "notes": {"type": ["string", "null"]}
      }
    },
    "reward": {
      "type": "object",
      "additionalProperties": false,
      "required": ["total", "components"],
      "properties": {
        "total": {"type": "number"},
        "components": {
          "type": "object",
          "required": ["task_success", "retrieval_hit", "tool_error", "user_correction", "latency", "context_cost", "useful_reuse"],
          "properties": {
            "task_success": {"type": "number"},
            "retrieval_hit": {"type": "number"},
            "tool_error": {"type": "number"},
            "user_correction": {"type": "number"},
            "latency": {"type": "number"},
            "context_cost": {"type": "number"},
            "useful_reuse": {"type": "number"}
          }
        }
      }
    }
  }
}