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GLOSSARY TERM

PEAC Protocol

PEAC Protocol is an open protocol for file-based policy discovery and verifiable receipts. Agents discover policies via /.well-known/peac.txt and present cryptographic PEAC-Receipt tokens as auditable proof of compliance.

How PEAC Protocol works

  1. Policy discovery - Agent fetches /.well-known/peac.txt to discover pricing, terms, and payment methods
  2. Payment flow - Agent makes payment through specified method (HTTP 402, x402, MCP, A2A, etc.)
  3. Receipt generation - Payment provider issues a PEAC-Receipt as a signed JWS token
  4. Receipt presentation - Agent presents receipt in PEAC-Receipt header for verified access

PEAC-Receipt format

A PEAC-Receipt is a JWS (JSON Web Signature) token containing payment proof, access rights, and compliance metadata. It can be verified offline using the issuer’s public key.

# Example PEAC-Receipt header
PEAC-Receipt: eyJhbGciOiJFZERTQSIsInR5cCI6InBlYWMtcmVjZWlwdC8wLjEiLCJraWQiOiJvcmlnaW5hcnktMjAyNS0wMSJ9...

# Decoded payload (example)
{
  "header": {
    "alg": "EdDSA",
    "typ": "peac-receipt/0.1",
    "kid": "originary-2025-01"
  },
  "payload": {
    "iss": "https://www.originary.xyz",
    "sub": "agent:client-123",
    "iat": 1734048000,
    "jti": "rcpt_xyz789",
    "peac": {
      "version": "0.11.0",
      "resource": "/api/content",
      "policy_hash": "sha256:9f3c..."
    },
    "payment": {
      "rail": "x402",
      "amount": "1.00",
      "currency": "USD"
    }
  }
}

PEAC vs x402

PEAC and x402 are complementary protocols:

  • PEAC - File-based policy discovery (/.well-known/peac.txt) and receipt format (PEAC-Receipt JWS)
  • x402 - HTTP 402-based payment flow with challenge-response pattern for inline payment negotiation

Many implementations use both: PEAC for policy discovery and x402 for payment enforcement.

Why verifiable receipts matter

  • Audit trails - Cryptographic proof of payment and access for compliance
  • Offline verification - JWS signatures can be verified without calling issuer APIs
  • Chargeback protection - Signed receipts prevent payment disputes
  • Attribution proof - Agents can prove they paid for content usage rights

Learn more