> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apiosk.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Apiosk Pay (Hosted Checkout)

> A marketplace hands off a payment to pay.apiosk.com and gets the buyer back with a result. The buyer's own wallet pays the seller, the marketplace, and Apiosk in one transaction.

# Apiosk Pay (Hosted Checkout)

Apiosk Pay is the **hosted checkout** at `https://pay.apiosk.com`. A marketplace
creates a checkout server-to-server, redirects the buyer to the URL it gets
back, and reads the result. The marketplace never renders a wallet UI, never
sees a signature, and never learns a settlement address. Same shape as iDEAL:
redirect out, pay, come back.

This is a different money path from the Connect skill charge in
[/guides/connect-marketplace](/guides/connect-marketplace). Both sit under
Apiosk Connect and both use your marketplace keys, but they settle differently:

|               | Hosted checkout                             | Skill charge                |
| ------------- | ------------------------------------------- | --------------------------- |
| Who pays      | a human buyer, in a browser                 | an agent, over x402         |
| Endpoint      | `POST /v1/checkout` on `pay.apiosk.com`     | `charge_url` on the gateway |
| Settlement    | one transaction, three recipients, on-chain | once to the platform wallet |
| Split happens | at payment time, atomically                 | later, at payout time       |
| Contract      | `ApioskPaySplitter`                         | none                        |

## The money moves payer to payee, nothing custodies it

A checkout is paid by **the buyer's own wallet, in one transaction**, to three
recipients at once: the seller, the marketplace owner, and Apiosk. It goes
through `ApioskPaySplitter`, a small ownerless contract that performs the
transfers and holds no balance at any point. There is no platform wallet in the
middle, no facilitator, and nothing to pay out afterwards. The split has already
happened when the transaction confirms.

The alternative was two or three separate transfers, and it was rejected for one
reason: a buyer who confirms the first and abandons the second has paid the
seller on-chain while the marketplace has not, with no way to undo it. The
splitter makes that state unrepresentable. Every leg lands, or the transaction
reverts.

## The split is per marketplace, and it is not yours to send

`marketplace_fee_bps` and `apiosk_fee_bps` are read from your marketplace row
behind the API key, never from the request body. A marketplace on 30% means 70%
to the seller, after Apiosk's 2%. Change the number in the portal and the next
checkout uses it, with no redeploy, and nothing in the contract knows what a fee
is.

Each fee leg is floored and the remainder goes to the seller, so the three legs
always sum to the gross exactly. A leg that computes to zero is dropped rather
than encoded.

| Party       | Share                                      |
| ----------- | ------------------------------------------ |
| Seller      | gross, minus the marketplace fee, minus 2% |
| Marketplace | its configured fee                         |
| Apiosk      | 2% platform fee                            |

## What the caller may not set

The body describes the **sale**. The key decides **who is selling**. Four things
are therefore resolved server-side and refused in the body:

* **Marketplace name and logo.** A caller that could name its own marketplace
  could render someone else's brand over its own checkout.
* **Fee basis points.** A caller that could set these could take a cut nobody
  agreed to.
* **Any wallet address.** The seller's payout address is resolved through
  Connect, where it was verified by a Sign-In-With-Ethereum signature. An
  address in a request body would mean a compromised integration could point a
  seller's takings anywhere. See [/pay/sellers](/pay/sellers).
* **`amount_minor`.** You send dollars. The service converts to USDC's 6 decimal
  minor units, so no integrator has to know the token's precision.

Everything resolved this way, all three recipients and all three amounts, is
**frozen onto the checkout at creation**. A seller who relinks their wallet, or
a marketplace that changes its cut, must not alter a price a buyer has already
been shown, and certainly not a transaction a wallet has already signed.

<Warning>
  No response from this service ever contains a settlement address. Not the
  seller's, not the marketplace's, not Apiosk's. A buyer who could read a payout
  address could be induced to send funds to it directly, outside the checkout,
  with no record and no split.
</Warning>

## Related links

* Quickstart: [/pay/quickstart](/pay/quickstart)
* Naming a seller: [/pay/sellers](/pay/sellers)
* API reference: [/pay/checkout-api](/pay/checkout-api)
* Payment lifecycle: [/pay/lifecycle](/pay/lifecycle)
* Webhooks: [/pay/webhooks](/pay/webhooks)
* Connect (marketplace): [/guides/connect-marketplace](/guides/connect-marketplace)