x402 refunds

Whether an x402 payment can be refunded depends on the payment scheme the seller offers in its 402.

By default the exact scheme settles only after the seller's handler succeeds, so a failed call is not charged. The auth-capture scheme adds void and refund for the seller, and reclaim for the buyer once the capture deadline passes. Before paying, a buyer can read what vet402 recorded when it paid the same seller.

1.The exact scheme

The exact scheme moves a fixed amount once. Its default payment flow, authorization, verifies the payment before the request runs and settles it afterwards, so a failed handler leaves the buyer uncharged. A seller can instead offer the upfront flow, which settles first. There a failed handler leaves the buyer charged, the scheme defines no refund, and any remedy is the seller's own arrangement, such as a new transfer back. The scheme is specified in the x402 repository.

2.The auth-capture scheme

The buyer authorizes a maximum amount. In the escrow flow the seller places a hold before serving the request, then captures what is owed or voids the hold afterwards. In the authorization flow the seller charges after serving the request, with no hold. In both flows a refund returns captured funds later, up to the amount captured and not yet refunded.

Two timestamps in the payment set the limits. captureDeadline is the last moment held funds can be captured, and from then the buyer can reclaim a hold that was never captured. refundDeadline is the last moment a refund can be issued. Capture, void and refund need the seller side to consent. The full rules are in the auth-capture specification.

3.How often a paid call comes back with nothing

vet402 buys from x402 sellers with its own wallets and records what came back. As of 2026-11-09 (UTC), it had 14427 settled payments. 504 of them came back with no usable content: a 5xx, a 202 Accepted, an empty 2xx body, or no status on record. 746 came back with a 4xx answer. vet402 holds those 4xx calls out of seller scores, because the request it sent may differ from what the seller expects. The breakdown by chain is in State of x402: November 2026.

4.Refund receipts

An individual Internet-Draft, draft-hopley-x402-refund-receipt, proposes a receipt format that records a refund as full, partial or rejected and links it to the original payment. It is an individual draft with intended status Informational, open for comment, as of 2026-11-12.

5.Check before paying

Read the scheme and extra.paymentFlow of each entry in accepts to see which rules apply. Then read the purchases vet402 made from that seller: GET /api/v1/check?url= answers with no key, and the hosted MCP server answers the same question for an agent. The steps are in How to check an x402 seller before paying, and the protocol is explained in What is x402.

vet402 does not hold customer funds or refund payments. It records purchases and publishes them.

6.Questions