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Quickstart: Verify Reputation

Look up and verify an on-chain attestation.

1. Install​

npm install @oma3/omatrust ethers @ethereum-attestation-service/eas-sdk

2. Look Up Attestations by Subject​

Use the same did:web:example.com from the Publish quickstart to find all attestations about that service:

import {
  listAttestations,
  verifyAttestation,
} from "@oma3/omatrust/reputation";

// You need an ethers v6 Provider connected to the chain where the attestation lives
const attestations = await listAttestations({
  subject: "did:web:example.com",                                                   // The DID you published in the quickstart
  provider,                                                                         // ethers v6 Provider
  easContractAddress: "0x8835AF90f1537777F52E482C8630cE4e947eCa32",                 // EAS contract on OMAChain Testnet
  schema: "string subject, string version, uint256 ratingValue, string reviewBody, string[] screenshotUrls, string[] proofs",
});

console.log(`Found ${attestations.length} attestation(s)`);
console.log(attestations[0].data.subject);      // "did:web:example.com"
console.log(attestations[0].data.ratingValue);   // 5

3. Verify Each Attestation​

for (const attestation of attestations) {
  const verification = await verifyAttestation({
    attestation,
    provider,
  });

  console.log(attestation.uid, verification.valid, verification.reasons);
}

verifyAttestation checks that the attestation is on-chain, not revoked, and that any attached proofs are valid. If no proofs were submitted with the attestation, it will flag that.

What's Next​