How do AI agents pay any business? The Merchant Payment Endpoint (MPE) explained
Answer
An AI agent usually knows who it wants to pay — "Acme GmbH", a VAT number, an invoice header — but not where to send the money. A Merchant Payment Endpoint (MPE) closes that gap: it resolves a business name or VAT number to validated payment details (IBAN/BIC with full structure and checksum validation, verification method disclosed in every response), and can chain straight into settlement. AsterPay operates an MPE as Layer 2 of its agent commerce stack — resolution is free, and
POST /v1/mpe/settle runs resolve → validate → trust check → SEPA Instant payout in one call.
The problem nobody built for
Agent payment protocols like x402 assume the agent already has a recipient address. Real commerce does not work that way. An agent processing an invoice, restocking inventory, or paying a supplier starts from a business identity: a legal name, a VAT number, a registry entry. Between that identity and a SEPA payment lies the lookup problem — and getting it wrong means money sent to the wrong account, which is exactly how invoice fraud drains billions from human accounts-payable teams every year.
What the MPE does
- Resolve —
GET /v1/mpe/merchants/resolve?business_id=FI12345678&business_id_type=vatlooks the business up in AsterPay's verified merchant registry and the merchant's published payment manifest (/.well-known/pay.json) and returns the IBAN/BIC. - Validate — the resolved IBAN passes full structure and checksum validation, and every response discloses the verification method used (
vop_method). Bank-side PSD2 Verification of Payee (VoP) name matching is being added via partner PSPs; the MPE never claims a name match it has not performed. - Settle —
POST /v1/mpe/settlechains the full pipeline: resolve, payee validation, the paying agent's KYA trust check, then USDC→EUR conversion and SEPA Instant payout. Agent pays stablecoins; the business receives euros, typically in under 10 seconds.
Where MPE sits in the stack
| Layer | Question it answers | AsterPay surface |
|---|---|---|
| Layer 1 — KYA trust | "Can I trust this agent?" | Trust score 0–100, sanctions, ERC-8004 identity |
| Layer 2 — MPE | "Where do I send the money?" | Resolve + validated IBAN |
| Layer 3 — Settlement | "How does it become euros?" | USDC→EUR via SEPA Instant |
What it costs
Resolution is free. Settlement carries the standard EUR fee: 0.5% + €0.10 per transaction on the EU rail (1.5% + €1.00 on the US rail). No subscription, no token — pay per settlement.
Try it
# Resolve a merchant by VAT number (free, no auth)
curl "https://x402.asterpay.io/v1/mpe/merchants/resolve?business_id=FI12345678&business_id_type=vat"
# Full pipeline: resolve → validate → KYA → SEPA Instant
curl -X POST "https://x402.asterpay.io/v1/mpe/settle" \
-H "Content-Type: application/json" \
-d '{"business_id":"FI12345678","business_id_type":"vat","amount_usdc":250}'