{
  "schema_version": "1.0",
  "id": "prompt-lab-token-metrics",
  "source": "PROMPT_LAB",
  "destination": "TOKEN_LAB",
  "status": "CONTRACT_READY",
  "fields": {
    "original_tokens": { "type": "integer", "minimum": 0 },
    "optimized_tokens": { "type": "integer", "minimum": 0 },
    "token_reduction": { "type": "number", "unit": "percent" },
    "estimated_cost": { "type": "number", "minimum": 0, "unit": "currency" },
    "model": { "type": "string" },
    "prompt_efficiency_score": { "type": "number", "minimum": 0, "maximum": 100 }
  },
  "notes": [
    "The score remains experimental until Prompt Lab defines its calculation method.",
    "The model field must refer to a record in /token-lab/models/index.json when cost is calculated."
  ]
}