// agent payments on sui

Agents can buy the services they need on Sui.

Tell your agent what it can buy and how much it can spend, then let it work. It pays per call in USDC on Sui and brings back a receipt you can check.

Services coming soon

you

generate an image of a red fox, paid

agent

○ fetch suipay.dev/SKILL.md → skill loaded

found openrouter-image · $0.05 / image, pay and continue?

○ POST /openrouter-image → 402 payment required

○ paying $0.05 USDC · settling on Sui…

✓ settled · digest 0x61b7…ddd7

✓ 200 OK · receipt attached

here's your image, $0.05, verifiable on Suiscan.

// how_sui_agent_payments_works

What happens on a paid call

The agent requests a service and receives a quote. The gateway checks the request against the spend account, settles on Sui, and lets the call through. The response comes back with a receipt attached.

Single PaymentRequestThe agent asks for a paid API and hits SuiPay

Buyerowner + agent

Sui Agentic PaymentsOperating layer

Sellerpaid API

Everything the gateway does

Discovery, payment, settlement, and receipts — the whole path from finding a service to verifying you paid for it.

Per-call pricing

Every service carries a price per call. The agent pays for what it uses, one call at a time. No signup required.

Settles on Sui

Settlement happens in USDC on Sui before the upstream call runs. The facilitator verifies the finalized onchain event before the resource is delivered, and every payment resolves to a digest you can open on Suiscan.

Onchain spend account

Owners fund one spend account per asset and grant agents scoped access to it: allowed services, a total budget, a per-payment cap, and an expiry. Enforced onchain at settlement, revocable at any time.

Machine-readable

The directory ships as a SKILL.md and a JSON endpoint. An agent can read it, compare prices, and buy without a human approving each call.

Works with your agent

Register the MCP server with Claude Code or Codex. The agent gets six tools: check access, discover, pay, fetch receipts, connect, disconnect.

Refundable offers

Sellers can mark an offer refundable. Settlement opens a shared RefundVault instead of paying the seller immediately, and a delivery failure inside the decision window can be refunded before the vault releases.

Frequently asked questions

What is Sui Agent Payments?

A catalog of paid APIs and the gateway that handles payment for them. Each listing carries a price per call. The gateway issues the HTTP 402, checks the request against the owner’s grant, and settles in USDC on Sui before the call runs.

Which standards does this implement?

Both MPP and x402. One 402 response can carry an MPP challenge in WWW-Authenticate and x402 offers in the JSON body — same challenge ID, same economic terms. A client uses whichever dialect the resource advertises, never both. The agent rail today advertises MPP.

Do agents need an account or an API key?

No. Pricing and payment travel in the HTTP exchange itself. Authority is an onchain grant plus a scoped delegate key, not a user account.

Does my agent hold my wallet?

No. Your wallet stays with you. The agent is a delegated signer on your spend account with its own scoped key — through MCP the platform custodies it, or you can bring your own. Either way, a leaked delegate key can only spend inside the grant’s onchain limits.

How do owners control spending?

A grant sets which services the agent can buy from, a total budget, a per-payment cap, the asset, and an expiry. All of it is onchain state enforced at settlement, not a server session, so a request outside it doesn’t settle. Revocable at any time.

What stops the agent buying something I didn’t intend?

It checks its access before spending and can only call services named in the grant. A request outside the grant returns GRANT_DENIED rather than a payment attempt.

What happens if the call fails after payment?

Settlement and delivery are separate outcomes, and the receipt is immutable evidence that payment happened. Preserve it and reconcile against chain state rather than paying again. If the offer carried signed refundable terms, a delivery failure inside the decision window can be refunded.

How do refunds work?

Only offers explicitly marked refundable use the refund flow. Settlement opens a shared RefundVault rather than paying the seller, and a classified delivery failure inside the decision window can be returned to the buyer. After the refund window closes, an unrefunded vault releases to the seller. An ordinary immediate payment is final.

What’s supported today?

Sui testnet, settling in USDC. Mainnet follows once the transaction path hardens.

How do I list a service?

Send the endpoint, a price per call, and a short description. You keep serving the endpoint you already run; the gateway handles the 402 and the settlement.