{
  "version": "SIU-2026a",
  "print_id": "2026-09-18-commodity",
  "date": "2026-09-18",
  "status": "provisional",
  "basket_costs": [
    {
      "model_id": "deepseek-v3.2",
      "cost_usd": "0.001813"
    },
    {
      "model_id": "llama-3.3-70b-deepinfra",
      "cost_usd": "0.000701"
    },
    {
      "model_id": "mistral-small-3.2-24b-instruct",
      "cost_usd": "0.000651"
    },
    {
      "model_id": "qwen-2.5-72b-instruct",
      "cost_usd": "0.002504"
    }
  ],
  "weights": {
    "source": "equal",
    "values": [
      {
        "model_id": "deepseek-v3.2",
        "weight": "0.250000"
      },
      {
        "model_id": "llama-3.3-70b-deepinfra",
        "weight": "0.250000"
      },
      {
        "model_id": "mistral-small-3.2-24b-instruct",
        "weight": "0.250000"
      },
      {
        "model_id": "qwen-2.5-72b-instruct",
        "weight": "0.250000"
      }
    ]
  },
  "dated_siu": "0.0014",
  "exchange_rate_table": [
    {
      "model_id": "deepseek-v3.2",
      "usd_per_siu": "0.0018",
      "spread_to_index": "0.2792",
      "siu_per_usd": "551.4"
    },
    {
      "model_id": "llama-3.3-70b-deepinfra",
      "usd_per_siu": "0.0007",
      "spread_to_index": "-0.5055",
      "siu_per_usd": "1426.5"
    },
    {
      "model_id": "mistral-small-3.2-24b-instruct",
      "usd_per_siu": "0.0007",
      "spread_to_index": "-0.5405",
      "siu_per_usd": "1535.2"
    },
    {
      "model_id": "qwen-2.5-72b-instruct",
      "usd_per_siu": "0.0025",
      "spread_to_index": "0.7667",
      "siu_per_usd": "399.3"
    }
  ],
  "sensitivity_block": [
    {
      "policy_variant": "cache-enabled: 40% of T2 input at 10% of input price",
      "dated_siu": "0.0009",
      "delta": "-0.3317",
      "applies_to": [
        "deepseek-v3.2",
        "llama-3.3-70b-deepinfra",
        "mistral-small-3.2-24b-instruct",
        "qwen-2.5-72b-instruct"
      ]
    },
    {
      "policy_variant": "batch-discount: 50% off input and output",
      "dated_siu": "0.0007",
      "delta": "-0.5000",
      "applies_to": [
        "deepseek-v3.2",
        "llama-3.3-70b-deepinfra",
        "mistral-small-3.2-24b-instruct",
        "qwen-2.5-72b-instruct"
      ]
    }
  ],
  "rounding": {
    "dated_siu_dp": 4,
    "basket_cost_dp": 6,
    "usd_per_siu_dp": 4,
    "spread_dp": 4,
    "siu_per_usd_dp": 1,
    "mode": "ROUND_HALF_UP",
    "siu_per_usd_mode": "ROUND_DOWN",
    "notes": "Applied at publication only; all intermediate arithmetic is full-precision decimal. basket_cost carries more decimal places than dated_siu so the published print is reproducible from its own published figures. siu_per_usd truncates so it never overstates the work a dollar buys."
  },
  "cost_of_production_usd": "0.0921",
  "price_snapshot_ref": "price-snapshot-merged-2026-09-18T00-59-09.366Z.json",
  "methodology_version": "v0-draft",
  "series": "commodity",
  "signature": "0xee8671870b6a20f16bdae9c18725ad70f882741a47772d419922c81b90fc3258477caa28b8af87bc9c25debbffd56283eb36301bd21b9ff5a39b0f6856525342",
  "public_key": "0x030c598ee35bd24b6942e9155bd36c1dbbe77936c700f859e75b0168b0e25cb299",
  "anchor": {
    "chain": "base-sepolia",
    "status": "anchored",
    "tx_hash": "0x7454228c4876a481001afcb544994dd63eca95c4c8b2a1ff85ccdbc6045d23c6",
    "posted_at": "2026-09-18T01:03:12.000Z"
  },
  "correction_notes": [
    {
      "published_at": "2026-09-25",
      "note": "dated_siu previously rounded to a fixed 4 decimal places rather than 4 significant figures — found live and fixed the same day, 2026-09-25 (docs/methodology.md's Rounding section). At this print's price level that was too coarse to show real day-to-day movement. This print's signed body is never edited — the published figure (0.0014) stands. Recomputed from this print's own published basket_costs and weights (Σ weight × basket_cost, rounded under the corrected 4-significant-figure rule, reproducible by anyone from this print's own published figures alone), the real value is 0.001417."
    },
    {
      "published_at": "2026-09-25",
      "note": "This print was published under the belief that cached-input pricing (rules-2026-09-13, commit 29d4be2) was already live — docs/methodology.md stated this as fact. It was not: buildModelInputs never forwarded a price snapshot's price_cached_in_usd_per_1m to the cost formula, for any model, from any source, until this was found and fixed live 2026-09-25 (commit 327d7b9, docs/methodology.md's rules-2026-09-25b). For this print specifically, real nonzero cached_input usage on deepseek-v3.2, mistral-small-3.2-24b-instruct — already present in this print's own run records — was still priced at zero in this print's own signed cost_of_production_usd and basket_costs, contrary to what the methodology this print's date falls under claimed. This print's signed body is never edited. The exact, per-model corrected dollar figure is not computed here — that quantified backfill is separate, deferred follow-up work; this note discloses the structural fact, not yet the number."
    }
  ]
}