Protocols
However an AI agent pays, AgentBank accepts it — with zero protocol code on your side. You price your goods; the agent picks whichever protocol it speaks; each order records which one was used. You don’t implement any of these.
The eight protocols, at a glance
Section titled “The eight protocols, at a glance”| Protocol | Pricing | Settles via |
|---|---|---|
| ACP — Agentic Commerce Protocol | Catalog or merchant-quoted | Card |
| UCP — the ucp.dev checkout wire | Catalog or merchant-quoted | Card or stablecoin |
| x402 — HTTP 402 + signed stablecoin authorization | Catalog or merchant-quoted | Stablecoin (USDC / RLUSD) |
| AP2 — Agent Payments Protocol (signed mandates) | Catalog | Card |
| A2A — Agent-to-Agent (hands off to ACP for the charge) | Catalog | Card |
| Visa TAP — Trusted Agent Protocol | Catalog | (records the intent) |
| Skyfire — KYAPay signed identity + payment token | Amount-driven | USDC or tokenized card |
| MPP — Machine Payments Protocol (HTTP-402, incl. Tempo) | Amount-driven | Stablecoin, incl. on-chain |
How a price is set
Section titled “How a price is set”- Merchant-quoted / amount-driven (the production model): the authoritative amount comes from the merchant’s signed request or a signed token/challenge — never from the buyer.
- Catalog-driven: the agent sends item ids + quantities and the gateway resolves the price from a catalog you registered — the agent can’t quote its own price (anti-fraud).
Discover a merchant’s protocols at runtime
Section titled “Discover a merchant’s protocols at runtime”Each merchant exposes a public, machine-readable discovery document listing the protocols it accepts and its endpoints:
GET https://mcp.curless.ai/v1/merchant/{merchantId}/.well-known/payments