Settlement Policy

What an x402 payment through our facilitator costs, what we accept, every reason we refuse one, and what happens when something breaks. Last updated October 19, 2026.

This policy exists in two forms: this page, and a machine-readable manifest agents can fetch and act on — GET https://x402-agent-pay.com/policy. Every 402 payment response names it.

What we accept

Field	Value
Asset	USDC
Network	Base L2 (chain 8453)
Mechanism	x402 v2 — EIP-3009 `transferWithAuthorization`
Payee	`0x367F…51a03` (AgentPay treasury)
Minimum	$0.001 USDC

What it costs

Service	Fee
Verify a payment	Free
Cost preview (`/facilitator/cost`)	Free — all-in cost before you sign
Dry-run a settle (`/facilitator/simulate`)	Free — verdict plus refusal reasons
Settle	No facilitator fee. The USDC transfers to the payee; settlement gas is on us for in-scope resources
Payee disbursement rail	1% of the disbursed amount, only on successful on-chain disbursement

We are scoped: the facilitator settles payments for resources paying the AgentPay treasury. It is not a public gas relay — payments to other payees are refused with PAYEE_NOT_SERVED_HERE.

Every refusal rule (fail-closed)

A payment that fails any of these checks never executes. The paid endpoint returns 402, nothing is charged, nothing settles.

Refusal	Meaning
`MALFORMED_PAYLOAD`	The payment header is not valid x402 JSON
`MISSING_AUTHORIZATION`	No EIP-3009 authorization in the payment
`MISSING_SIGNATURE`	No EIP-712 signature over the authorization
`SIGNATURE_MISMATCH`	The signature does not recover to the payer
`UNSUPPORTED_SCHEME`	Not an x402 v2 payment
`UNSUPPORTED_NETWORK`	Chain is not Base L2
`UNSUPPORTED_ASSET`	Asset is not USDC
`MALFORMED_AMOUNT`	Amount is not a valid integer
`INSUFFICIENT_AMOUNT`	Below the $0.001 minimum
`WRONG_PAYEE`	`payTo` is not the treasury address
`PAYEE_NOT_SERVED_HERE`	Payee is outside facilitator scope
`AUTHORIZATION_NOT_YET_VALID`	Authorization `validAfter` is in the future
`AUTHORIZATION_EXPIRED`	Authorization `validBefore` has passed
`AUTHORIZATION_ALREADY_USED`	This authorization nonce has already been spent on-chain
`INSUFFICIENT_FUNDS`	Payer balance below the amount
`STALE_SIMULATION`	The state has moved since your dry-run snapshot
`SETTLE_UNREACHABLE`	Settlement provider unreachable; nothing charged
`CHAIN_READ_FAILED`	On-chain state unreadable; nothing charged
`RATE_LIMITED`	Too many requests; retry after the window

When something breaks

Fail-closed everywhere. Verification runs before any paid work. An unverifiable payment is refused, never guessed at.
Idempotent settles. A nonce already spent on-chain for the same resource counts as already-settled — you are never double-charged.
Free previews. Use /facilitator/cost and /facilitator/simulate before signing anything. Both are free, both send no payment.
Receipts on-chain. Recent settlements are public at /facilitator/recent and in real time at /facilitator/live, each with a Base tx hash.
A real channel. File a report with your tx hash at the feedback rail (free). Verified failures are repaid in USDC on Base per our refund policy.

Fetch it like an agent

curl https://x402-agent-pay.com/policy

One JSON file: scheme, accepted tokens, fees, refusal rules, failure handling, discovery links. CORS-enabled, no key required. Try the whole payment flow free in the sandbox wizard first.