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HTTP 402 Payment Required, put to work

Payment terms in one HTTP response.

x402 uses the HTTP status 402, Payment Required, to describe a payment. A compatible client reads the terms, asks a wallet to approve the exact amount and recipient, and retries after settlement.

See how it settles Read the protocol docs
  • HTTP carries the terms
  • The wallet approves
  • USDC settles to the merchant

The server answers

402 Payment Required
amount
29.00 USDC
asset
USDC
network
selected live rail
payTo
0x71C4…4e2b
protocol fee
0

The client hands the terms to the wallet

Your wallet asks

Approve 29.00 USDC to 0x71C4…4e2b?

Nothing moves until you approve.

Under the hood

One request, drawn end to end.

Every role the payment passes through: the buyer's wallet, the merchant site, the facilitator and network, and the merchant's wallet. Settlement time depends on the live network and facilitator.

  1. 01 Request the paid resource The page or API is priced. Buyer wallet to Merchant site: GET /report.
  2. 02 Receive the payment terms Amount, asset, network, recipient. Merchant site to Buyer wallet: 402 + terms.
  3. 03 Approve in the wallet The buyer sees the exact terms. Buyer wallet: signs.
  4. 04 Retry with the authorization A single-use signed payment. Buyer wallet to Merchant site: X-PAYMENT.
  5. 05 Verify and settle On the selected live rail. Merchant site to Facilitator + network: settle.
  6. 06 USDC reaches the merchant wallet LinkSell never holds it. Buyer wallet to Merchant wallet: USDC.
  7. 07 Return the paid response The request loop closes. Merchant site to Buyer wallet: 200 OK.

The buyer's view

  1. 01

    You reach a paid page

    You click buy, or an app you use does. Instead of a card form, the server replies with a short machine-readable note: this costs 29 USDC.

  2. 02

    Your wallet signs

    Your wallet reads the note and asks you to approve one payment. You see the exact amount and the recipient first. Nothing is charged until you approve.

  3. 03

    The selected rail settles

    The selected facilitator and network settle the authorized USDC to the merchant wallet. LinkSell does not create a merchant balance.

What a buyer needs

Four things are in place before a checkout completes.

  • Wallet Signs the terms
  • Live network A supported rail
  • USDC The requested amount
  • Costs shown Reviewed before signing

Ready to pay

The merchant's view

Why merchants use it,
and where each fact stops.

Each statement sits next to the condition that limits it.

  • Fees

    x402 has no protocol fee, and LinkSell charges 0% commission per sale.

    Where it stops: Plan fees, and network, facilitator, wallet, or conversion costs can apply.

  • Settlement

    The buyer authorizes USDC to the merchant wallet.

    Where it stops: The selected live rail controls finality.

  • Custody

    LinkSell does not hold merchant funds.

    Where it stops: A facilitator and a network remain external.

  • Offers

    Hosted checkout for products, services, subscriptions, downloads, and paid APIs.

    Where it stops: You configure each offer; availability can depend on the plan.

LinkSell hosts x402 checkout
so you don't have to.

The technical detail, including the 402 challenge, the signed payment header, and a sample client, lives in the developer docs.

Request access Read the protocol docs