Touchstone Assay
Dated SIU — SIU-2026a
$0.01251
30 Sep 2026 provisional
▼ -27.8% since 29 Sep 2026 — Cheaper than the previous print. Falling prices are the expected direction for this index over time.
Equal weighting, disclosed: basket costs span 4.4× across the 5 qualifying constituents. 2 of 5 constituents (40%) sit at or above the mean basket cost and together account for 65% of the summed basket cost Dated SIU is computed from — equal weighting still gives each of them the same 1÷5 nominal share. Dated SIU therefore tracks the more expensive end of the basket more closely than a demand-weighted index would. See the methodology's Weighting section, and Frontier SIU / Commodity SIU, the tier prints published alongside this one for exactly this reason.

Exchange-rate table

ModelUSD / SIUSpread to indexSIU per $1
claude-sonnet-5 $0.0233 +86% 42.9
gpt-5.1 $0.0090 -28% 110.5
gemini-3.1-pro-preview — — —
undefined class: T1 (no run records for this class); T2 (no run records for this class); T3 (no run records for this class)
grok-4.6 $0.0173 +38% 57.7
claude-haiku-4-5 $0.0076 -39% 131.1
gpt-5.4-mini $0.0053 -58% 190.3

Floor & market spread

Not yet published — the floor needs a measured hardware-rental rate for the reference configuration, which this print does not yet include.

Sensitivity

The print recomputed under alternative cache and batch-discount policies, so the effect of those policy choices is stated rather than hidden inside one number.

Policy variantDated SIUDeltaApplies to
cache-enabled: 40% of T2 input at 10% of input price $0.008659 -30.8% claude-sonnet-5, gpt-5.1, gemini-3.1-pro-preview, grok-4.6, claude-haiku-4-5, gpt-5.4-mini
batch-discount: 50% off input and output $0.006277 -49.8% claude-sonnet-5, gpt-5.1, gemini-3.1-pro-preview, grok-4.6, claude-haiku-4-5, gpt-5.4-mini

Methodology, signature & anchor

Methodology
v0-draft
Methodology revision
rules-2026-09-26
Cost of production
$1.0090
Signature
0x273278f8…79054a6f
Public key
0x030c598e…e25cb299
Anchor tx — Base Sepolia
0xe90f9c98…d5a07864 (base-sepolia)
Anchor tx — Arc Testnet
not anchored: anchoring on Arc Testnet began with the print dated 2026-10-15
Raw runs
https://github.com/petrkrulis2022/dated-siu-inference/tree/main/data/runs/2026-09-30-frontier

Dated SIU is an assessment of qualifying inference work under this basket version, model/provider configuration and quality gate — not a prediction of production agent costs, which vary with workflow design, tool reliability, retry policy and context handling.

Verify this yourself

Don't take this page's word for it — every value below is checkable independently. Read the steps, run one command, or have an agent read verify.json.

The body hash

Body hash
0xa8bec3091c9b38b2301b8b9d09274217836cea83119980caa78ce4cfc0015028
Recovered signer
0x284ff2f8605ff8afeda6959b856bb7e6d48f845a

The body hash is made like this:

  1. Download this print's JSON: https://raw.githubusercontent.com/petrkrulis2022/dated-siu-inference/main/data/prints/2026-09-30-frontier.json.
  2. Remove exactly these five fields and keep everything else as published: signature, public_key, anchor, superseded_by, correction_notes. The last three are added after signing, which is why they cannot be part of the hash.
  3. Canonicalise what is left with RFC 8785 (JCS): keys sorted, no whitespace, numbers and strings as JSON writes them.
  4. Take the keccak256 hash of the UTF-8 bytes of that text (the original Keccak padding Ethereum uses, not NIST SHA3-256). Written as 0x and 64 hex digits, it equals the body hash above.
Or run one command 
curl -O https://prints.touchstoneassay.com/verify-print.mjs
node verify-print.mjs 2026-09-30-frontier

Plain Node 18 or later, nothing to install, no keys. It does the four steps above, then looks the anchor transaction up on the chain's explorer and looks for a PrintPosted event carrying your hash. Exit code 0 means it matched. It does not check the signature: see the recovered signer above and the publisher below.

Anchored on Base Sepolia

TouchstoneAttestation
0xF60701793eD168ffd6e818e1DCcb600393297190 (base-sepolia · chain id 84532)
Publisher (fixed in the contract)
0x284ff2F8605Ff8AFeDa6959B856Bb7E6d48f845a — the recovered signer above is this publisher
Anchor tx
0xe90f9c98e3ef4188b7f135a4937959968af19805a1499da98a974320d5a07864 (base-sepolia)
  1. Open the contract link above on its explorer, go to "Read Contract", call publisher(), and confirm it equals the recovered signer shown above.
  2. On the same "Read Contract" tab, call postedAt(bytes32) with the body hash above and confirm it returns a non-zero timestamp: the Unix time, in seconds, at which this hash was first recorded.
  3. Open the anchor transaction, go to its Logs tab, and confirm a PrintPosted event whose bodyHash equals the body hash above.

Anchored on Arc Testnet

TouchstoneAttestation
0x12b886b043feABc3d90bBae3ae206d22b208160d (arc-testnet · chain id 5042002)
Publisher (fixed in the contract)
0x284ff2F8605Ff8AFeDa6959B856Bb7E6d48f845a — the recovered signer above is this publisher
Anchor tx
not anchored: anchoring on Arc Testnet began with the print dated 2026-10-15

All prints