index41

index41 proves transaction A executed before transaction B inside an Ethereum block — a fact carried in no payload and readable by no oracle — and makes a relay’s bond pay for breaking its no-sandwich promise.

The 30-second path

1. Open the landing page and scroll to the ledger. Three rows of a real Ethereum mainnet block light up in sequence — the positions are decoded live, in front of you.
2. Read the banner above the ledger. It names which of the two real sources is on screen right now: a live chain read, or the captured artifact if the public node is down. There is no third source.
3. Click re-read the chain. That hits /api/proof, which performs a real eth_getTransactionReceipt against a public CC3 node every time.
4. Check us against a stranger: the ruling on Blockscout (the contract is source-verified, so the explorer decodes the events itself), and the mainnet block the positions came from.

The receipt

Read live from the chain just now. Every row is checkable at a link on this page.

Reproduce it

No flags switch the judged capability on or off. There is no offline mode, no mock and no demo toggle anywhere in this repository.

# the demo surface — zero config, no .env, no wallet
npm install && npm run dev            # → http://localhost:3000

# re-read every live source and diff the committed artifact
node scripts/capture-proof.mjs --check

# the full on-chain run: deploy → bond → prove → pay, on CC3 testnet
# (needs a funded CC3 key at ~/.config/creditcoin/index41-testnet.json)
npm run build:cc3 && npm run prove -- --fresh-court

# the contract suite
npm test                              # forge test --summary — 120 tests

# one-line independent check of a position, against a stranger's API
curl -s https://eth.blockscout.com/api/v2/transactions/0xec3777f9d0e55d03b9caa3a4b8a786dd62e16eeb327a9f1c45dfbc79af618436 | jq .position

What this does not do

• It cannot prove state. Attestcoin commits transaction history, not state, so harm is the attacker's realized profit read from proven Swap logs — never a counterfactual against a pre-sandwich reserve ratio. A contract claiming otherwise would be lying, so this one does not offer it.
• It does not detect sandwiches on-chain. The caller supplies three transaction hashes; the contract rules on them. The pipeline and scripts/find-sandwich.ts find real ones off-chain.
• One bonded relay, one ruling. A multi-relay registry and a historical-claim browser were cut deliberately, not missed. The unit tests cover the mechanism; the deployed contract has ruled once, on the sandwich above.
• Testnet, unaudited. CC3 testnet, 102031. The bond is play money until it is not.
• Three of the 120 unit tests prove the mock, not the precompile. Unit tests run on a bare EVM where the precompile address holds no code, so the laterality tests assert against MockVerifier's Solidity reimplementation. The real precompile was confirmed separately, live on CC3 — docs/spike-output.txt.

Everything else

• The demo surface
• The proof, as JSON
• README — the full argument
• docs/PIPELINE.md — how the proof is built and audited
• docs/DEPLOYMENT.md — every deploy, bond and balance
• The ruling transcript
• The replay guard refusing a second claim
• Index41.sol

The three mainnet transactions this ruling is over: 14 0xec3777…618436 · 15 0x7b0541…4485a0 · 16 0xb0cae3…5be23a