{
  "name": "Contract",
  "type": "object",
  "properties": {
    "contract_number": {
      "type": "string",
      "description": "Contract Number format CT-#### (auto-generated)",
      "pattern": "^CT-[0-9]{4}$"
    },
    "contract_name": {
      "type": "string",
      "description": "Descriptive contract name"
    },
    "contract_type": {
      "type": "string",
      "enum": [
        "MSA",
        "SOW",
        "Rate Agreement",
        "Service Agreement",
        "NDA",
        "Amendment"
      ],
      "description": "Type of contract"
    },
    "vendor_id": {
      "type": "string",
      "description": "Vendor party to this contract"
    },
    "vendor_name": {
      "type": "string",
      "description": "Vendor name"
    },
    "client_id": {
      "type": "string",
      "description": "Client/Business ID party to this contract"
    },
    "client_name": {
      "type": "string",
      "description": "Client/Business name"
    },
    "sector_id": {
      "type": "string",
      "description": "Sector this contract falls under (if applicable)"
    },
    "sector_name": {
      "type": "string"
    },
    "partner_id": {
      "type": "string",
      "description": "Partner ID (if partner-specific)"
    },
    "partner_name": {
      "type": "string"
    },
    "procurement_manager": {
      "type": "string",
      "description": "Procurement manager who owns this contract"
    },
    "rate_card_id": {
      "type": "string",
      "description": "Reference to RateCard entity if rates are defined there"
    },
    "effective_start_date": {
      "type": "string",
      "format": "date",
      "description": "Contract effective start date"
    },
    "effective_end_date": {
      "type": "string",
      "format": "date",
      "description": "Contract end date"
    },
    "status": {
      "type": "string",
      "enum": [
        "draft",
        "pending_review",
        "active",
        "expiring",
        "expired",
        "terminated",
        "amended"
      ],
      "default": "draft",
      "description": "Contract lifecycle status"
    },
    "billing_terms": {
      "type": "string",
      "description": "Net 15, Net 30, Net 45, Net 60, etc."
    },
    "payment_terms": {
      "type": "string",
      "description": "Payment terms and conditions"
    },
    "auto_renew": {
      "type": "boolean",
      "default": false,
      "description": "Whether contract auto-renews"
    },
    "renewal_notice_days": {
      "type": "number",
      "description": "Days notice required before renewal/termination"
    },
    "document_url": {
      "type": "string",
      "description": "URL to the signed contract document"
    },
    "total_contract_value": {
      "type": "number",
      "minimum": 0,
      "description": "Total estimated contract value"
    },
    "signed_by_vendor": {
      "type": "string",
      "description": "Name of vendor signer"
    },
    "signed_by_client": {
      "type": "string",
      "description": "Name of client signer"
    },
    "signed_date": {
      "type": "string",
      "format": "date",
      "description": "Date contract was fully executed"
    },
    "amendments": {
      "type": "array",
      "description": "List of contract amendments",
      "items": {
        "type": "object",
        "properties": {
          "amendment_number": {
            "type": "number"
          },
          "description": {
            "type": "string"
          },
          "effective_date": {
            "type": "string",
            "format": "date"
          },
          "document_url": {
            "type": "string"
          }
        }
      }
    },
    "compliance_requirements": {
      "type": "array",
      "description": "Compliance requirements tied to this contract",
      "items": {
        "type": "string"
      }
    },
    "notes": {
      "type": "string",
      "description": "Additional notes"
    }
  },
  "required": [
    "contract_name",
    "contract_type",
    "vendor_id",
    "client_id",
    "status"
  ]
}