Invoice Passport

Open-source building blocks for invoices that both people and AI agents can issue, pay and verify: compliant e-invoices for many countries, payments on any rail (bank transfer, stablecoins, agent payment protocols), and a signed proof that ties each invoice to its payment.

Why. AI agents are starting to buy and sell: API calls, data, services. They can already pay (x402, MPP, stablecoins), but businesses still need a proper invoice for every payment, in the format their country requires, and a way to prove which payment settled which invoice. This library is that missing layer, and the engine behind Billify.

What it does

• Invoices for every market. One invoice model, many official formats: Peppol BIS 3.0 (EU), XRechnung (Germany), Factur-X PDF/A-3 (France, Germany), PINT AE (UAE mandate), PINT SG (Singapore InvoiceNow) and RO e-Factura (Romania), all checked against the official validators. Per-country rules (VAT/GST, tax ids, the currency tax must be shown in, e-invoicing mandates) for the EU, UAE, Singapore, UK, Switzerland, Panama and offshore hubs.
• Payments by humans and agents. Payable invoices over HTTP 402: x402 and the Machine Payments Protocol (MPP) with USDC on Base. Direct stablecoin payments to the seller's own wallet (Base, Ethereum, BNB Chain, Robinhood Chain) matched by a unique amount. Bank transfers matched from ISO 20022 statements (camt.052/053/054) by RF reference. Agent micro-payments consolidated into one invoice per payer and month, with every transaction hash attached.
• Proof of payment. An Invoice Passport is a signed JSON record from the issuer with the invoice, the parties, the payment evidence on whichever rail the money moved, and the history. Anyone with the issuer's public keys can verify it (SPEC.md). A paid passport can also be issued as a UN/CEFACT Verifiable Trade Documents PaymentConfirmation credential (W3C VC, did:web).
• Privacy, optional. Agents and auditors can fetch invoices and proofs through the Anyone network so servers never see who is asking.
• Accounting. Exchange rates from the source each jurisdiction accepts (ECB, BNR, HMRC, the CBUAE peg) for tax amounts in local currency and accounting exports.

TypeScript for Deno, Node 20+, browsers and edge runtimes. The core uses only WebCrypto; Factur-X PDFs use pdf-lib. Apache-2.0.

What is included

Usage

import { loadSigningKey, signPassport, verifyPassport } from "./mod.ts";

const key = await loadSigningKey(Deno.env.get("PASSPORT_SIGNING_JWK"));
const jws = await signPassport(input, key!); // input: PassportInput, see src/passport.ts

const result = await verifyPassport(jws, { keys: [key!.publicJwk] });
if (result.ok) console.log(result.passport.payment);

RO e-Factura XML:

import { buildUblInvoice } from "./mod.ts";

const { xml, problems } = buildUblInvoice(invoice);
if (!xml) console.error(problems); // missing or invalid data is reported, never guessed

Peppol BIS Billing 3.0 with an RF payment reference:

import { buildPeppolInvoice, creditorReference } from "./mod.ts";

const reference = creditorReference(invoiceNumber); // e.g. "RF47INV20260042"
const { xml, problems } = buildPeppolInvoice({ ...invoice, payment: { iban, reference } });

Record the matching bank transfer as passport evidence:

import { bankTransferEvidence, findCreditorReference } from "./mod.ts";

const rf = findCreditorReference(remittanceText); // from the bank statement
const evidence = bankTransferEvidence({ scheme: "SEPA", amount, currency: "EUR", recordedAt, creditorReference: rf });

Match a bank statement to open invoices:

import { evidenceForMatch, parseCamt, reconcile } from "./mod.ts";

const { transactions } = parseCamt(camtXml);
const { matches, ambiguous, unmatched } = reconcile(transactions, openInvoices);
for (const m of matches.filter((m) => m.autoApply)) {
  markPaid(m.invoice.id, evidenceForMatch(m, new Date().toISOString()));
}

Verify a passport from the command line:

deno task verify vectors/passport.jws --jwks vectors/jwks.json
deno task verify passport.jws --jwks https://issuer.example/.well-known/jwks.json

Demo: pay an invoice in USDG on Robinhood Chain

examples/robinhood-usdg-pay-invoice.ts sends the exact amount shown on an invoice in USDG on Robinhood Chain (chain id 4663) with your own key, read from the environment for that run only.

Private agent payments over Anyone (optional)

Agents and auditors can read invoices, pay them and verify the proof without revealing their IP address, through a local Anyone client (SOCKS5h on port 9050, DNS resolved by the network). Tested on the live network: a Billify Invoice Passport fetched and verified in about 1.4 s, the payment MCP in under 1 s.

npx @anyone-protocol/anyone-client                       # starts the client
deno run --allow-net --allow-env examples/agent-pay-over-anyone.ts --token <public invoice token>

examples/agent-pay-over-anyone.ts reads the invoice's MPP challenge, pays the exact USDC amount on Base (RPC traffic also through Anyone, only with PAYER_PRIVATE_KEY), presents the transaction as an MPP hash credential, and verifies the signed Invoice Passport. Payment over x402 or MPP needs no API key or account, so nothing ties the agent to a login either.

In code: anyoneFetch() returns a fetch that goes through the client, anyoneHttpClient() plugs into libraries that take fetch options (e.g. viem), anyoneReachable() tells whether a client is running, and the verifier CLI has --anyone. This hides the network origin, not the payment: the paying wallet is public on chain, and B2B invoices still name the buyer.

Browser verifier

Serve the repository root (for example python3 -m http.server) and open /web/. It verifies a passport against the issuer's JWKS, optionally checks that an e-invoice XML file is the one the passport refers to, and shows the invoice, payment evidence and history. Nothing leaves the browser.

Development

deno task test      # unit tests and test vectors
deno task check     # type check
deno lint
deno task vectors   # regenerate vectors/ after a deliberate format change
deno task bundle    # rebuild web/invoice-passport.js
deno task conformance  # XSD + official EN 16931 / Peppol schematron on every XML vector (needs Python 3, xmllint)

Scope

• Agent payments: x402 v2 and MPP (evm charge, hash credentials) for USDC on Base; consolidated invoices for micro-payments with every transaction hash attached.
• Stablecoin payments to the seller's own wallet, matched by a unique pay amount per invoice.
• Bank reconciliation: camt.052/053/054 import and matching by RF reference, invoice number + amount, or amount.
• Peppol BIS Billing 3.0 for EU invoicing: VAT categories S, Z, E, AE, K, G, O, mixed rates, RF payment reference, tax currency, attachments, and the fatal national rules for DE, IT and NL sellers.
• XRechnung 3.0 (Germany) and Factur-X EN 16931 (France, Germany): PDF/A-3b validated with veraPDF and Mustang, including the French reform rules (BR-FR).
• PINT AE (UAE e-invoicing mandate) and PINT SG (InvoiceNow), validated with the official PINT and jurisdiction schematron.
• RO e-Factura (CIUS-RO 1.0.1), accepted by ANAF's validator.
• Signatures: ES256 only.
• Credit notes (type 381, with the credited invoice) for Peppol BIS, XRechnung, CII / Factur-X, PINT AE (with the UAE credit reason code) and PINT SG.
• Planned: RO e-Factura CreditNote (storno invoices work today), more national formats, key rotation guidance.

Origin

Extracted from Billify, which issues Invoice Passports in production.

License

Apache License 2.0. Copyright 2026 Ovidiu Chintovan.