Carbon credits, with a recall.

Recourse reads the registry and watches the forest. If a credit is recalled, it can't be used, and whoever paid for it is refunded.

Registry figures from Verra's public registry, read 21 Oct 2026. Chain state from Base Sepolia.

Three steps, each one on-chain.

A registry hold, a satellite alarm or a published finding becomes a state every buyer, exchange and auditor can read, and a rule the contracts enforce.

1

Read the registry

Verra's own API response is proven with a zkTLS proof and checked inside the contract. The request is pinned byte for byte, so the status on-chain is the status Verra served.

8 project statuses and 8 retirements proven on Base Sepolia.Check a registry proof yourself
2

Watch the forest

A satellite detector compares Sentinel-2 dry seasons inside each project boundary. A notice reader extracts holds, withdrawals and over-issuance findings from public statements. Both sign their output; nothing acts until a reviewer confirms or the dispute window closes.

Detector F1 0.46 against Hansen forest loss (AUC 0.97); notice reader F1 0.99 on 47 documents.How each model is measured
3

Refuse and refund

The credit gate refuses recalled or on-hold credits at the point of use. A retirement backs one claim only. A warranty escrow pays the buyer back from the holdback when a recall lands.

7 refusals recorded on-chain, each with its reason.Try to use an on-hold credit

A hold at the registry doesn't reach the market.

Verra lists 290 projects as on hold or withdrawn. Their credits are still held, still listed on exchanges, and still retired into corporate claims.

1.73Mtonnes retired in the last 12 months from projects on hold or withdrawn.696 retirement records
22.6Mcredits from those projects still held in registry accounts.22,555,554 credits
9.72Mof them listed on exchanges, where nothing tells a buyer about the hold.9,716,942 credits
63%of those retired tonnes name no public beneficiary, so the claim behind them can't be checked.1,090,726 t

Source: Verra's public registry data (S&P Global platform), read 21 Oct 2026; snapshot sha256 0xd2e9a3ce68…. All exposure numbers

One recall, everywhere it matters.

When a finding is confirmed, the recall is a single on-chain state. Exchanges, claim registers and escrows read the same state, so the consequence arrives everywhere at once.

How the Kariba recall propagates from the registry to listings, claims and escrowsVerra statement, 23 Sep 202515,220,520of 26,822,953 credits issued in excess,read by the notice oracleVerra registry APIWithdrawnstatus proven on-chain with azkTLS proof of Verra's responseRecourse, on-chainRecalled56.74% haircutoracle proposed it, a reviewercountersigned, the recall is activeExchange listings770,163 credits listedintegrators ask the gate and halt salesNew retirements and claims87 retirements in 12 monthsnew claims refused: RecallActiveClaims already made56.74% no longer backedmarked impaired, never deletedEscrowed purchasesholdback refundedbuyer gets 56.74% of the price back, up to the holdbackHow the Kariba recall propagates from the registry to listings, claims and escrowsVerra, 23 Sep 202515,220,520of 26,822,953issued in excess,read by the notice oracleVerra registry APIWithdrawnstatus provenon-chain with azkTLS proofRecourse, on-chainRecalled56.74% haircutoracle proposed it, a reviewercountersigned, the recall is activeExchange listings770,163 credits listedintegrators ask the gate, halt salesNew retirements and claims87 retirements in 12 monthsnew claims refused: RecallActiveClaims already made56.74% no longer backedmarked impaired, never deletedEscrowed purchasesholdback refunded56.74% of the price back, capped
Kariba REDD+ (VCS 902). Excess figures from Verra's statement of 23 Sep 2025; listings and retirements from Verra's registry, read 21 Oct 2026; recall state read from the contracts.

Nothing here asks for trust.

Every number links to its source. Every model was scored against a pre-registered protocol. Every evidence bundle verifies in your browser.

Contracts on Base Sepolia

Credit gate
0x9185e4…c1F9D6
Integrity registry
0x6B64CE…0659c5
Registry oracle
0x10327C…718a06
Warranty escrow
0xeCa8B3…a60674
Claims ledger
0x6D5594…a019cb
All addresses, ABIs and the run log

Measured, pre-registered

0.35/0.68satellite precision/recall vs Hansen GFC, 6 projects
0 of 3stable-forest controls that fired
0.97/1.00notice reader precision/recall, answer key written first
100%prompt-injection documents refused
Scorecards, controls and limits

Footprint

Satellite model training: 0.0050 kWh, CPU only.Inference over 10 areas: 0.0028 kWh.Notice reader, all 621 model calls: 7.0 Wh (estimated).Ledger: Base, a proof-of-stake rollup. Commitments on-chain, data off-chain.
How these were measured

Check a credit before you count it.

Paste a Verra serial number. You get a verdict for general use, CORSIA, Türkiye's ETS and VCMI claims, read from the contracts.