An ERC‑8004 validator
with no keys and
no opinion.

An agent finishes a job and says it was paid. Who checks?

ERC‑8004, the Trustless Agents standard, answers with a Validation Registry. Work is submitted, a validatorAddress responds with a score from 0 to 100, and that score becomes the agent's on‑chain reputation.

The standard names three ways to fill that slot. A human reviewer, who can be lazy or bought. A staked node, only as honest as its stake is large. A TEE, which is a hardware vendor's promise.

So the standard called "Trustless Agents" settles its most consequential question — did this actually happen? — by picking whom to trust.

A contract does not need an opinion.

validatorAddress is an address. The spec constrains it no further. An address can be a contract.

Creditcoin's Attestcoin Protocol exposes a block‑prover precompile at 0x0FD2 that verifies natively, with no oracle operator, that a transaction was included in a finalized block of an attested chain. So a validator can be a contract that answers 100 only when the work is provable on Ethereum mainnet.

No keys. No stake. No quorum. Nothing to bribe, because there is nobody to bribe.

Inclusion is not success.

The block prover precompile does not validate if a transaction was successful or not. Attestcoin Protocol documentation

A transaction that reverted, ran out of gas, or moved nothing at all is still in the block — and it proves exactly as well as one that transferred a million dollars. A validator that stops at "the proof verified" will settle a payment that never happened.

Warrant decodes the receipt from the proven transaction bytes. Four invariants must hold before it will answer 100.

Two payments. One block. Two answers.

Both are real USDC transfers on Ethereum mainnet, sitting in the same block. Same Merkle root, same continuity proof, same attestation. One moved 45.00 USDC. One reverted and moved nothing.

The protocol is the trust model, not a feature.

// AttestcoinValidator.sol — I-1 INCLUSION
try NativeQueryVerifierLib.getVerifier().verify(
    chainKey, c.blockHeight, txb, c.merkleProof, c.continuityProof
) returns (bool ok) {
    if (!ok) return _reject(requestHash, txKey, "INCLUSION");
} catch {
    return _reject(requestHash, txKey, "INCLUSION");
}

Warrant occupies the validatorAddress slot of an otherwise ordinary Validation Registry. ValidationRegistry.sol knows nothing about Attestcoin — it is the spec surface, unmodified. Warrant is a drop‑in for any ERC‑8004 deployment, not a fork of one.

Check it yourself.

Deployed on Creditcoin CC3 testnet, chain 102031. All three contracts verified on Blockscout.

# reproduce the thesis without deploying anything
git clone https://github.com/Leihyn/warrant && cd warrant
forge test                                     # 4/4
cd tools && npm install && cd ..
node tools/warrant.mjs preflight 0x415fab30…2d7ea6   # the reverted one