@peac/adapter-eat is a Layer 4 adapter that decodes COSE_Sign1 structures (RFC 9052) containing Entity Attestation Token payloads and maps them into Interaction Record format claims. It verifies Ed25519 signatures, enforces a 64 KB size limit before CBOR decode to prevent denial-of-service, and hashes all claim values with SHA-256 by default so that no raw attestation data leaks into PEAC receipts.

How Do I Use It?

Decode and verify an EAT passport

import { decodeEatPassport } from '@peac/adapter-eat';

const result = await decodeEatPassport(coseBytes, publicKey);

if (result.verified) {
  console.log('Claims:', result.claims);
  console.log('Algorithm:', result.headers.alg); // -8 (EdDSA)
}

Map EAT claims to PEAC receipt claims

import { decodeEatPassport, mapEatClaims } from '@peac/adapter-eat';

const result = await decodeEatPassport(coseBytes, publicKey);
if (result.verified) {
  // Privacy-first: all values are SHA-256 hashed by default
  const mapped = await mapEatClaims(result.claims);
  console.log('Type:', mapped.type); // 'org.peacprotocol/attestation'
  console.log('Pillars:', mapped.pillars); // ['identity']
  console.log('Values:', mapped.values); // Map<number, string> with hashed values

  // Opt in to raw values when needed
  const raw = await mapEatClaims(result.claims, { includeRawClaims: true });
}

Integrates With

@peac/kernel (Layer 0): Wire constants and types
@peac/schema (Layer 1): Interaction Record format claim schemas
@peac/crypto (Layer 2): Ed25519 signature verification and SHA-256 hashing
@peac/protocol (Layer 3): Receipt issuance with mapped EAT claims

For Agent Developers

If you are building an agent that needs to verify device or entity attestations:

Use decodeEatPassport() to decode and verify COSE_Sign1 tokens from hardware or software attestation sources
Use mapEatClaims() to convert verified attestations into PEAC receipt claims with privacy-safe defaults
Only Ed25519 (COSE algorithm -8) is supported; all other algorithms are rejected
See the llms.txt for a concise protocol overview