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Version: v0.12.8

How Do I...

Quick answers to common tasks. Each answer includes a code snippet and a link to the full guide.

Verify a receipt?​

Three ways to verify:

CLI:

Terminal
npx peac verify eyJhbGciOiJFZERTQSIs... --issuer https://api.example.com

MCP Server (via AI agent):

MCP tool call
{ "tool": "peac_verify", "arguments": { "receipt": "eyJ...", "issuer_url": "https://api.example.com" } }

Programmatic:

verify.ts
import { verifyLocal } from '@peac/protocol';
const result = await verifyLocal(receipt, publicKey, { issuer: 'https://api.example.com' });

See: Verification | CLI Reference | MCP Server

Issue a receipt?​

issue.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',
    sub: 'user:agent-123',
    amt: '10.00',
    cur: 'USD',
    rail: 'x402',
  },
});

Or use Express middleware for automatic issuance:

express.ts
import { peacMiddleware } from '@peac/middleware-express';
app.use(peacMiddleware({ privateKey, kid, issuer }));

See: Quickstart | Express Middleware

Add receipts to my MCP server?​

Use @peac/mappings-mcp to attach evidence to MCP tool responses via _meta fields:

mcp-attach.ts
import { attachMcpCarrier } from '@peac/mappings-mcp';

const toolResponse = attachMcpCarrier(originalResponse, {
  receipt_ref: 'sha256:abc123...',
  receipt_jws: 'eyJhbGciOiJFZERTQSIs...',
});

See: Agent Protocols | MCP Server

Carry evidence through A2A?​

Use @peac/mappings-a2a to attach and extract evidence from A2A metadata:

a2a-attach.ts
import { attachA2aCarrier, extractA2aCarrier } from '@peac/mappings-a2a';

const artifact = attachA2aCarrier(originalArtifact, {
  receipt_ref: 'sha256:abc123...',
  receipt_jws: 'eyJhbGciOiJFZERTQSIs...',
});

const carrier = extractA2aCarrier(incomingMessage);

See: A2A Integration | Evidence Carrier

Record payment evidence?​

Use the appropriate rail adapter:

payment.ts
import { extractX402Evidence } from '@peac/adapter-x402';
const evidence = extractX402Evidence({ paymentHeader, amount: '0.001', currency: 'USDC', network: 'base' });

import { fromStripePaymentIntent } from '@peac/rails-stripe';
const evidence2 = fromStripePaymentIntent(paymentIntent);

See: Payment Rails | x402 Integration

Observe content signals?​

signals.ts
import { parseRobotsTxt, parseTdmRep, resolveSignals } from '@peac/mappings-content-signals';

const robots = parseRobotsTxt(robotsTxtContent, 'PEACBot');
const tdmrep = parseTdmRep(tdmrepJsonContent);
const observation = resolveSignals({ robotsTxt: robots, tdmRep: tdmrep });
// { train: 'deny', search: 'allow', inference: 'unspecified', ... }

See: Content Signals

Test conformance?​

Terminal
# Run basic conformance
npx peac conformance run --level basic

# Run full conformance suite
npx peac conformance run --level full --issuer https://api.example.com

See: Conformance Levels | CLI Reference

Create an evidence bundle?​

CLI:

Terminal
npx peac bundle create --receipts r1.jws r2.jws --issuer https://api.example.com --output evidence.peac.tar.gz

MCP Server:

MCP tool call
{ "tool": "peac_create_bundle", "arguments": { "receipts": ["<jws1>", "<jws2>"], "issuer_url": "https://api.example.com" } }

See: Evidence Bundles | CLI Reference

Record inference evidence?​

inference.ts
import { fromChatCompletion } from '@peac/adapter-openai-compatible';

const evidence = fromChatCompletion(response, { messages });
// SHA-256 digests only -- no raw text stored

See: Inference Receipts

Next steps​

Quickstart

Issue and verify your first receipt in under 5 minutes.

Choose Your Path

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