{
  "tool_id": "art-681-best-execution-evidence-pack",
  "note": "Golden vectors authored by BESTEX-PACK-BUILD-1 per BESTEX-PACK-BUILD-SPEC.md. Vector 1 is the spec canonical preimage; its execution_hash pins 6bd25c0cf93b2ab0a11d5df456dcb996c1f2c9a04c8b6d49f01a07532518d5e3 (byte-exact parity target). Vector 2 is the opposite-verdict vector (WITHIN_POLICY, no negative-improvement venues declared). Vector 3 is the fail-closed vector. All venue fills and improvements are declared inputs; no runtime clock anywhere. human_sign_off: PENDING.",
  "vectors": [
    {
      "name": "spec-canonical-preimage (parity pin 6bd25c0c)",
      "policy_parameters": {
        "venues": [
          { "venue": "V1", "fills": 60, "avg_improvement_bps": 2.1 },
          { "venue": "V2", "fills": 40, "avg_improvement_bps": -0.4 }
        ]
      },
      "output_payload": {
        "weighted_improvement_bps": 1.1,
        "negative_venues": ["V2"],
        "trace": "(60*2.1 + 40*-0.4)/100 = (126-16)/100 = 1.1",
        "overall": "REVIEW_ITEM_FLAGGED"
      },
      "golden_hash": "6bd25c0cf93b2ab0a11d5df456dcb996c1f2c9a04c8b6d49f01a07532518d5e3"
    },
    {
      "name": "opposite-verdict within policy",
      "policy_parameters": {
        "venues": [
          { "venue": "A", "fills": 10, "avg_improvement_bps": 1.25 },
          { "venue": "B", "fills": 30, "avg_improvement_bps": 0.5 }
        ]
      },
      "output_payload": {
        "weighted_improvement_bps": 0.69,
        "negative_venues": [],
        "trace": "(10*1.25 + 30*0.5)/40 = (12.5+15)/40 = 0.69",
        "overall": "WITHIN_POLICY"
      },
      "golden_hash": "d97459e8706d7121b80ede539550909442586eceebe7f5791e30bf32b10e38d1"
    },
    {
      "name": "fail-closed empty input",
      "policy_parameters": {},
      "output_payload": {
        "weighted_improvement_bps": null,
        "negative_venues": null,
        "trace": "fail-closed: venues must be a non-empty array of declared venue records; no evidence pack computed -- correct the named inputs and resubmit. Best-execution monitoring arithmetic over caller-declared synthetic inputs only: not investment advice, not a best-execution determination, and not a regulatory submission. Rounding declaration: emitted numbers are 2dp half-up.",
        "overall": null,
        "domain_errors": ["INVALID_VENUES"]
      },
      "golden_hash": "ce0cd10a1a96dee0cc385ad11ed12497a742fa94e796017ce611f4bfa7d13b76"
    }
  ]
}