{
  "version": "SIU-2026a",
  "print_id": "2026-09-20-commodity",
  "date": "2026-09-20",
  "status": "provisional",
  "basket_costs": [
    {
      "model_id": "deepseek-v3.2",
      "cost_usd": "0.001835"
    },
    {
      "model_id": "llama-3.3-70b-deepinfra",
      "cost_usd": "0.000719"
    },
    {
      "model_id": "mistral-small-3.2-24b-instruct",
      "cost_usd": "0.000660"
    },
    {
      "model_id": "qwen-2.5-72b-instruct",
      "cost_usd": "0.002537"
    }
  ],
  "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": "0.2763",
      "siu_per_usd": "544.8"
    },
    {
      "model_id": "llama-3.3-70b-deepinfra",
      "usd_per_siu": "0.0007",
      "spread_to_index": "-0.4999",
      "siu_per_usd": "1390.6"
    },
    {
      "model_id": "mistral-small-3.2-24b-instruct",
      "usd_per_siu": "0.0007",
      "spread_to_index": "-0.5411",
      "siu_per_usd": "1515.4"
    },
    {
      "model_id": "qwen-2.5-72b-instruct",
      "usd_per_siu": "0.0025",
      "spread_to_index": "0.7646",
      "siu_per_usd": "394.1"
    }
  ],
  "sensitivity_block": [
    {
      "policy_variant": "cache-enabled: 40% of T2 input at 10% of input price",
      "dated_siu": "0.0010",
      "delta": "-0.3319",
      "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": "0.0934",
  "price_snapshot_ref": "price-snapshot-merged-2026-09-20T04-31-44.700Z.json",
  "methodology_version": "v0-draft",
  "series": "commodity",
  "signature": "0x7994300c8838d5e1d0c3dfec56f32e92270c5bcf0e6aa6e2fbb03c2f6d0835ef7b4f508c9fb3bc2e916492a3bfbbb7d2140546c8bb918edbf326dfd5205f1536",
  "public_key": "0x030c598ee35bd24b6942e9155bd36c1dbbe77936c700f859e75b0168b0e25cb299",
  "anchor": {
    "chain": "base-sepolia",
    "status": "anchored",
    "tx_hash": "0xb42674616c372222336098b7c7eece3cadd517b69b94e9561a12efad384f5725",
    "posted_at": "2026-09-20T04:34:38.000Z"
  },
  "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 0.001438."
    },
    {
      "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."
    }
  ]
}