{
  "version": "SIU-2026a",
  "print_id": "2026-10-16-frontier",
  "date": "2026-10-16",
  "status": "provisional",
  "basket_costs": [
    {
      "model_id": "claude-sonnet-5",
      "cost_usd": "0.023440"
    },
    {
      "model_id": "gpt-5.1",
      "cost_usd": "0.009204"
    },
    {
      "model_id": "gemini-3.1-pro-preview",
      "cost_usd": "0.040094"
    },
    {
      "model_id": "grok-4.6",
      "cost_usd": "0.017467"
    },
    {
      "model_id": "claude-haiku-4-5",
      "cost_usd": "0.007679"
    },
    {
      "model_id": "gpt-5.4-mini",
      "cost_usd": "0.005294"
    }
  ],
  "weights": {
    "source": "equal",
    "values": [
      {
        "model_id": "claude-sonnet-5",
        "weight": "0.166667"
      },
      {
        "model_id": "gpt-5.1",
        "weight": "0.166667"
      },
      {
        "model_id": "gemini-3.1-pro-preview",
        "weight": "0.166667"
      },
      {
        "model_id": "grok-4.6",
        "weight": "0.166667"
      },
      {
        "model_id": "claude-haiku-4-5",
        "weight": "0.166667"
      },
      {
        "model_id": "gpt-5.4-mini",
        "weight": "0.166667"
      }
    ]
  },
  "dated_siu": "0.01720",
  "exchange_rate_table": [
    {
      "model_id": "claude-sonnet-5",
      "usd_per_siu": "0.0234",
      "spread_to_index": "0.3631",
      "siu_per_usd": "42.6"
    },
    {
      "model_id": "gpt-5.1",
      "usd_per_siu": "0.0092",
      "spread_to_index": "-0.4647",
      "siu_per_usd": "108.6"
    },
    {
      "model_id": "gemini-3.1-pro-preview",
      "usd_per_siu": "0.0401",
      "spread_to_index": "1.3316",
      "siu_per_usd": "24.9"
    },
    {
      "model_id": "grok-4.6",
      "usd_per_siu": "0.0175",
      "spread_to_index": "0.0158",
      "siu_per_usd": "57.2"
    },
    {
      "model_id": "claude-haiku-4-5",
      "usd_per_siu": "0.0077",
      "spread_to_index": "-0.5535",
      "siu_per_usd": "130.2"
    },
    {
      "model_id": "gpt-5.4-mini",
      "usd_per_siu": "0.0053",
      "spread_to_index": "-0.6922",
      "siu_per_usd": "188.9"
    }
  ],
  "sensitivity_block": [
    {
      "policy_variant": "cache-enabled: 40% of T2 input at 10% of input price",
      "dated_siu": "0.01247",
      "delta": "-0.2747",
      "applies_to": [
        "claude-sonnet-5",
        "gpt-5.1",
        "gemini-3.1-pro-preview",
        "grok-4.6",
        "claude-haiku-4-5",
        "gpt-5.4-mini"
      ]
    },
    {
      "policy_variant": "batch-discount: 50% off input and output",
      "dated_siu": "0.008713",
      "delta": "-0.4933",
      "applies_to": [
        "claude-sonnet-5",
        "gpt-5.1",
        "gemini-3.1-pro-preview",
        "grok-4.6",
        "claude-haiku-4-5",
        "gpt-5.4-mini"
      ]
    }
  ],
  "rounding": {
    "dated_siu_sig_figs": 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. dated_siu rounds to significant figures, not a fixed decimal-place count, so its precision scales with the price rather than being lost as it falls (found live, 2026-09-25 — see docs/methodology.md's Rounding section). basket_cost carries more decimal places than dated_siu needs at any price level so the published print stays reproducible from its own published figures. siu_per_usd truncates so it never overstates the work a dollar buys."
  },
  "cost_of_production_usd": "1.6478",
  "price_snapshot_ref": "price-snapshot-merged-2026-10-16T00-55-00.158Z.json",
  "methodology_version": "v0-draft",
  "methodology_revision": "rules-2026-09-26",
  "series": "frontier",
  "signature": "0xbe8caca2cdfb33913c3842f031d64193ab59d8070ac1db705438f64819e5fb0a30553db2f0a1057e00eebe0d111ee1b36ff96105876a6b40e2d0654aec926672",
  "public_key": "0x030c598ee35bd24b6942e9155bd36c1dbbe77936c700f859e75b0168b0e25cb299",
  "anchor": {
    "chain": "base-sepolia",
    "status": "anchored",
    "tx_hash": "0xde4f7b10ef3fc944809cfe8f49c92ca38b4deff94152008e6eb635ef48292a3d",
    "posted_at": "2026-10-16T00:58:08.000Z",
    "additional_anchors": [
      {
        "chain": "arc-testnet",
        "status": "anchored",
        "tx_hash": "0xc6c194d3dc6b774c6e66ab0b5688e66e29ef06174dc005ff744553be6b265c7a",
        "posted_at": "2026-10-16T00:58:10.000Z"
      }
    ]
  }
}