COMPARISON
API Economy
Commerce
x402 vs ACP
API-call settlement vs conversational consumer checkout.
x402 and ACP are sometimes pitched as alternatives. They are not. x402 lives at the API layer — a 402 response and a stablecoin transfer settle a single call. ACP lives at the consumer-checkout layer — a Checkout object lets ChatGPT push a cart through to a Shopify-anchored merchant. They settle different things at different layers.
x402
vs
ACP
Side-by-side
The dimensions that actually matter.
| Dimension | x402 | ACP |
|---|---|---|
| Layer | API request / response | Consumer checkout in chat |
| Originator | Coinbase + Cloudflare | Stripe + OpenAI |
| Surface | Any HTTP client (agent or human) | ChatGPT and OpenAI surfaces |
| Settlement | On-chain stablecoin transfer | Stripe SharedPaymentToken on cards |
| Merchant set | Any API operator | Etsy, Glossier, Vuori, Spanx, SKIMS, Shopify merchants |
| Best for | Per-call APIs, agent-to-agent settlement | Consumer goods purchased via chat |
Decision matrix
Which one, when.
x402
Pick x402 when…
- You are monetising an API or service consumed by agents.
- Sub-second settlement and zero merchant accounts matter.
- You want HTTP-native interop, no chat surface required.
ACP
Pick ACP when…
- You are a consumer brand that wants to be buyable inside ChatGPT.
- Your customers expect Stripe-grade payments, refunds, and dispute flows.
- Conversational checkout is a primary distribution channel.
both
Use both when…
- You operate APIs (x402) and a consumer storefront (ACP).
- An agent calls APIs to research, then completes checkout for a human.
- You need shared spending policies across both moments.
Bottom line
x402 settles a request. ACP settles a cart. They will coexist for years and most agents will use both — APIs on x402, consumer goods on ACP — with one policy plane on top.
How xpay fits
xpay sits above both. Whether the agent's next move is an x402 API call or an ACP checkout, the same governance and audit trail apply.