@notary402/x402

Audit & compliance wrapper for x402 payments. Budget enforcement, audit logging, and spike detection for AI agent micropayments.

Install

npm install @notary402/x402

Quick Start

import { wrapWithNotary, standardPolicy } from "@notary402/x402";

const fetch = wrapWithNotary(x402Fetch, {
  agentId: "researcher-01",
  budget: standardPolicy(),
});

// Every payment is now tracked, budget-enforced, and audit-logged
const res = await fetch("https://api.example.com/data");

Budget Policies

import { standardPolicy, conservativePolicy, permissivePolicy } from "@notary402/x402";

// Standard: $1/call, $25/hr, $100/day, $1000 total
standardPolicy()

// Conservative: $0.10/call, $5/hr, $20/day, $200 total
conservativePolicy()

// Permissive: $10/call, $100/hr, $500/day, $10000 total
permissivePolicy()

// Custom
standardPolicy({
  perCall: 0.5,
  hourly: 10,
  allowlist: ["https://api.example.com/*"],
})

Stateful Client

import { NotaryClient, standardPolicy } from "@notary402/x402";

const notary = new NotaryClient({
  agentId: "researcher-01",
  budget: standardPolicy(),
  onAuditEvent: (event) => console.log(event),
});

const fetch = notary.wrap(x402Fetch);
await fetch("https://api.example.com/data");

// Check stats
console.log(notary.stats());
// { totalPayments: 1, totalSpent: 0.002, ... }

// Export audit log
const csv = notary.exportCSV();

Webhook Integration

const fetch = wrapWithNotary(x402Fetch, {
  agentId: "researcher-01",
  budget: standardPolicy(),
  webhookUrl: "https://hooks.slack.com/services/...",
});

Error Handling

import { BudgetExceededError, EndpointBlockedError } from "@notary402/x402";

try {
  await fetch("https://api.example.com/data");
} catch (err) {
  if (err instanceof BudgetExceededError) {
    console.log(`Budget exceeded: ${err.policy} limit $${err.limit}`);
  }
  if (err instanceof EndpointBlockedError) {
    console.log(`Endpoint blocked: ${err.url}`);
  }
}

License

MIT