{
      "tool_id": "art-309-parametric-index-deriver",
      "tool_version": "1.0.0",
      "display_name": "Parametric Index Deriver",
      "mcp_name": "derive_parametric_index_from_receipts",
      "mandate_type": "compliance_mandate",
      "wave": 54,
      "gpu": false,
      "url": "https://ainumbers.co/chaingraph/art-309-parametric-index-deriver.html",
      "description": "Deterministically aggregates a named metric (mean, sum, count, max, or min) across a receipt set into a parametric index value: receipts as an oracle replacement, replay-on-challenge instead of trust-the-feed. Feeds the shipped compute_parametric_trigger_payout kernel, which performs the actual trigger-vs-payout math; this kernel never reimplements that logic. The index is a replayable derived value, never a settlement trigger by itself. Not the same as check_agency_eligibility_matrix or any lending eligibility tool -- this is an insurance-evidence parametric index. Zero network, zero PII.",
      "input_schema_ref": "chaingraph/art-309-parametric-index-deriver.html#manifest",
      "deadline": null,
      "consumes": [],
      "feeds": [
        "art-251-compute-parametric-trigger-payout"
      ],
      "status": "live",
      "conformance_fixtures": true,
      "compute_capability": "server",
      "compute_images": [{"system":"sha256-source","image_id":"sha256:69501cd554f59d8ca92176964a10773dad63d5b7c1e4ae06af5eda6fbe9d29c6","valid_from":"2026-07-10"},{"system":"risc0","image_id":"sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6","valid_from":"2026-06-28"}],
      "compute_proof": {
        "type": "ZkVmReceipt",
        "system": "risc0",
        "receiptFormat": "groth16-bn254",
        "imageId": "sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6",
        "seal": "Akf3Ftq4keVXkwYiCtB5/0v/ZdRv0H30cy2nH3k0Y5YnKEoNEDEcqyEjlzm/JTmRDG0UE0YsA9R+VqoB+zSv7gXZW8GCuWMtXO6YjZWYXNJCu4QMQfjVytF4pCg4utKNBrUtuDZBgXiYQpmrvJ7d56P0NtuQkqlAa6zeXq27tLsn+PbhGPiDNhdEXhhbAK0GhscBD7n7Ie/XmxTwdy/W9Ar/w535cV0DrCHsTacDXu4oGKgSKrwvWGIOT/i9UZ/KDHUhcBx6v3HxUofk8VNyP33994xDTg4EEu26r6qzILwVjbkPYcc5NH2wrph5OjWZDSKwNpVBJXbBtlHprhHfOw==",
        "journal": {
          "chaingraph_version": "0.4.0",
          "kernel_digest": "sha256:69501cd554f59d8ca92176964a10773dad63d5b7c1e4ae06af5eda6fbe9d29c6",
          "output": {
            "aggregation": "mean",
            "contributing_receipts": 3,
            "index_value": 20,
            "insufficient_evidence": false,
            "metric": "wind_speed_mph",
            "window": {
              "from": "2026-08-01",
              "to": "2026-08-31"
            }
          }
        }
      },
      "export_capability": [
        "json",
        "vc"
      ]
    }