Quickstart

Issue and verify your first PEAC receipt in under 5 minutes. By the end, you'll have a signed receipt and a working verification pipeline.

Prerequisites

Node.js 22+ required. Check with node --version.

Step 1: Install

Terminal

npm install @peac/protocol

This installs the core protocol package with issuance, verification, and schema validation.

Step 2: Generate a signing key

Terminal

npx @peac/cli keygen

This outputs an Ed25519 keypair. You'll get two values:

• Private key: Store securely (environment variable, secret manager)
• Public key: Publish at /.well-known/peac-issuer.json for verifiers

Keep your private key secret

Never commit private keys to source control. Use environment variables or a secret manager.

Step 3: Issue a receipt

Wire 0.1 (flat claims)

issue-wire-01.ts

import { issue } from '@peac/protocol';

const receipt = await issue({
  privateKey: process.env.PEAC_PRIVATE_KEY,
  kid: 'peac-2026-03',
  claims: {
    iss: 'https://api.example.com',
    aud: 'https://client.example.com',
    amt: 100,
    cur: 'USD',
    rail: 'x402',
  },
});

// Deliver as HTTP header
res.setHeader('PEAC-Receipt', receipt);

Wire 0.2 (structured kinds + extensions)

issue-wire-02.ts

import { issueWire02 } from '@peac/protocol';

const receipt = await issueWire02({
  privateKey: process.env.PEAC_PRIVATE_KEY,
  kid: 'peac-2026-03',
  claims: {
    iss: 'https://api.example.com',
    kind: 'evidence',
    type: 'org.peacprotocol/payment',
    pillars: ['commerce'],
    extensions: {
      'org.peacprotocol/commerce': {
        payment_rail: 'x402',
        amount_minor: '10000',
        currency: 'USD',
      },
    },
  },
});

res.setHeader('PEAC-Receipt', receipt);

The receipt is a compact JWS string: a single line of base64url-encoded data.

Step 4: Verify a receipt

verify.ts

import { verifyLocal } from '@peac/protocol';

const result = verifyLocal(receiptJWS, publicKey);

if (result.valid) {
  console.log('Wire version:', result.wireVersion); // '0.1' or '0.2'
  console.log('Claims:', result.claims);

  if (result.wireVersion === '0.2') {
    console.log('Kind:', result.claims.kind);
    console.log('Type:', result.claims.type);
  }
} else {
  console.log('Verification failed:', result.reason);
}

verifyLocal() auto-detects wire version and works completely offline: no network calls to the issuer.

Step 5: Publish your policy

Create /.well-known/peac.txt on your domain:

/.well-known/peac.txt

version: 0.12.3
protocol: peac
peac:
  consent:
    ai_training: conditional
  economics:
    pricing: $0.01/gb
  attribution:
    required: true

This is your machine-readable terms file. AI agents discover it automatically before making requests.

Step 6: Publish your keys

Create /.well-known/peac-issuer.json:

/.well-known/peac-issuer.json

{
  "keys": [
    {
      "kty": "OKP",
      "crv": "Ed25519",
      "use": "sig",
      "kid": "peac-2026-03",
      "x": "<base64url-encoded-public-key>",
      "alg": "EdDSA"
    }
  ],
  "receipt_versions": ["peac-receipt/0.1", "interaction-record+jwt"]
}

This is a standard JWKS. Verifiers fetch it to validate your receipts.

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What you've built

After completing these steps, you have:

1. A signing pipeline: Your service can issue receipts on every response
2. A verification pipeline: Any client can verify your receipts offline
3. Machine-readable policy: Agents discover your terms automatically
4. Published keys: Verifiers can validate without contacting you

Next steps

Express middleware

Auto-issue receipts on every Express.js response with one middleware.

MCP server

Let AI agents verify receipts natively via Model Context Protocol.

Receipt format

Deep dive into claims, lifecycle stages, and extensions.

Payment rails

Attach payment evidence from x402, Stripe, Razorpay, or card networks.