x402 is an open standard for paying for HTTP requests. A server answers 402 Payment Required with payment terms, and the client pays and repeats the request with proof of payment.

No. x402 is a protocol. Payments use existing assets such as USDC. Tokens that use the x402 name are not part of the standard.

Coinbase created x402 and contributed it to the x402 Foundation, which operates under the Linux Foundation.

Which networks does x402 support?

The exact scheme has specifications for EVM chains, Solana, Stellar, XRPL, Algorand, Aptos, Sui, NEAR, TON, Hedera, Starknet, Cardano and more. vet402 buys on the chains listed above.

Can an x402 payment be refunded?

Under the exact scheme a settled payment is final. The auth-capture scheme adds capture, void and refund within deadlines that the payment sets.

How can an agent know an x402 seller will deliver?

x402 proves that a payment happened. To see what a seller returned, an agent can read vet402's records of real purchases from that seller before it pays.

Independent Measurementx402 referenceLedger read 2026-11-09 15:19 UTC

vet402x402 Economy2026-11-10

x402: the HTTP 402 payment standard, explained with live data

x402 is an open payment standard that lets a client, often an AI agent, pay for an HTTP request. The server answers 402 Payment Required with its terms, the client signs a payment, often in USDC, and sends the same request again with the payment attached. vet402 buys from x402 sellers and publishes what each purchase delivered, so this page pairs the explanation with live numbers from those purchases.

How an x402 payment works

The client requests a paid resource, for example an API endpoint.
The server answers HTTP 402 with a PAYMENT-REQUIRED header. It carries base64 JSON with one or more accepted options: a scheme, a network, an asset, an amount and a recipient (payTo).
The client picks an option, signs a payment payload and repeats the request with a PAYMENT-SIGNATURE header.
The server, usually through a facilitator, verifies and settles the payment, then returns the resource with a PAYMENT-RESPONSE header that describes the settlement.

A facilitator is a service that verifies and submits payments for one or more networks, so a resource server can accept x402 without running its own node. Header names are from x402 v2. Version 1 used X-PAYMENT and carried the terms in the response body. x402 v2 specification

Payment schemes

x402 payment schemes
Scheme	What it does
exact	Transfers a fixed amount that the server knows in advance. It moves once and the scheme has no refund step.
upto	Authorizes up to a maximum amount. The server charges the actual amount at settlement, for usage based pricing.
batch-settlement	The client gives a signed payment commitment, access is granted at once, and the transfer settles later in a batch defined by the network.
auth-capture	The client authorizes a maximum. The server can hold, capture, void or refund the payment within deadlines, and the client can reclaim a hold the server never captured.

Under exact, the payment is final once it settles. vet402's purchases tell a buyer what came back from a seller before it signs, which matters most under exact. Scheme specifications

Who maintains x402

Coinbase contributed the x402 protocol to the x402 Foundation, which the Linux Foundation announced as operational on July 14, 2026. The Foundation runs the protocol under open governance. The specification and reference SDKs live in the x402-foundation/x402 repository on GitHub. x402.org announcement, GitHub repository, docs.x402.org. vet402 is an independent measurement service and is not part of the x402 Foundation.

Live data: what x402 sellers delivered

As of 2026-11-09 15:19 UTC

Settled means vet402 re-read the transfer on chain. Delivered means the payment settled and the paid request answered 2xx, other than 202 Accepted, with a non-empty body.

Purchase attempts: 21,040
Settled: 14,384
Delivered: 13,135
Delivered share: 87.9% of 14,951 purchases with a final outcome
Endpoints with at least one delivery: 8,170

L1 purchases by chain
Chain	Purchases	Delivered
Base	17,273	10,584
Solana	1,349	1,020
Celo	461	403
Tempo (MPP)	393	113
Arc	375	264
Arbitrum One	341	240
Stellar	316	296
XRPL	294	131
BNB Chain	169	52
Avalanche C-Chain	69	32

Full state of x402, State API (JSON), Purchases as CSV. Data under CC BY 4.0.

Cite as: KIZUNA Creation. vet402 observatory. Dataset, retrieved 2026-11-09. https://vet402.com/api/v1/observatory/state

Check an x402 seller before paying

A 402 tells a buyer the price and the recipient. It does not say what will come back. Before an agent signs, it can read what vet402 received when it paid the same seller, and compare the 402 in hand with the terms of the last purchase that delivered. How to check a seller, Hosted MCP server, Decision API

x402 by chain

Assets, networks and live counts for each chain vet402 buys on.

Base, Solana, Tempo, XRPL, Arc, Celo, Stellar, Arbitrum One, BNB Chain, Avalanche C-Chain, All chains, Stablecoin payments over x402

Questions about x402

What is x402?: x402 is an open standard for paying for HTTP requests. A server answers 402 Payment Required with payment terms, and the client pays and repeats the request with proof of payment.
Is x402 a token?: No. x402 is a protocol. Payments use existing assets such as USDC. Tokens that use the x402 name are not part of the standard.
Who created x402?: Coinbase created x402 and contributed it to the x402 Foundation, which operates under the Linux Foundation.
Which networks does x402 support?: The exact scheme has specifications for EVM chains, Solana, Stellar, XRPL, Algorand, Aptos, Sui, NEAR, TON, Hedera, Starknet, Cardano and more. vet402 buys on the chains listed above.
Can an x402 payment be refunded?: Under the exact scheme a settled payment is final. The auth-capture scheme adds capture, void and refund within deadlines that the payment sets.
How can an agent know an x402 seller will deliver?: x402 proves that a payment happened. To see what a seller returned, an agent can read vet402's records of real purchases from that seller before it pays.