createCheckout()

The SDK's front door. Resolves a sparse merchant config into a fully-defaulted checkout handle whose methods map 1:1 to the wire endpoints and MCP tools.

createCheckout(config) is the one call a merchant makes. It resolves a sparse CheckoutConfig into a fully-defaulted handle — minting a receipt-signing key if you didn't supply one, wiring the default in-memory store, and defaulting the rails to [x402, mock].

import { createCheckout, BALANCED } from '@veto-protocol/checkout';

const checkout = createCheckout({
  merchant: { id: 'acme', name: 'Acme Corp', domain: 'shop.acme.example' },
  catalog: [
    { sku: 'widget', name: 'Blue Widget', price: { amount: '12.50', currency: 'USD' }, available: true },
  ],
  receiving: { x402: { chain: 'base', address: '0xYourAddress', asset: 'USDC' } },
  policy: BALANCED(),
});

The handle

Every method maps 1:1 to a wire endpoint (and to an MCP tool):

Method	Endpoint
`manifest()`	`GET /.well-known/agentic-checkout.json`
`catalog()`	`GET /agent/catalog`
`createSession(body)`	`POST /agent/checkout`
`settle(id, body)`	`POST /agent/checkout/{id}/settle`
`getSession(id)`	`GET /agent/checkout/{id}`
`verifyReceipt(jws)`	offline receipt verification
`receiptPublicJwk()` / `receiptJwks()`	the published verifying key

`CheckoutConfig`

Field	Notes
`merchant`	`{ id, name, domain }`.
`catalog`	A `CatalogItem[]` or a (possibly async) function for dynamic inventory.
`receiving`	Non-custodial per-rail destinations — your address.
`policy`	A `MerchantPolicy` (start from a preset).
`rails`	Defaults to `[x402, mock]` when omitted.
`store`	A `SessionStore`; defaults to in-memory `MemoryStore`.
`trustedIssuers`	`{ veto: { jwksUrl?, jwks? } }` for mandate verification.
`receiptSigningKeySeedB64`	base64 32-byte Ed25519 seed; autogenerated if absent.
`sessionTtlSeconds`	Default 900.
`taxRate`	Default 0.
`intentMatcher`	Optional `(intent, cart) => 0..1` score for intent policy.
`onEvent`	Optional fire-and-forget terminal telemetry hook.

Hosted and self-hosted merchants run the identical SDK — only the store differs. Use loadCheckoutConfig() to compile persisted rows into the exact CheckoutConfig the handle consumes.

The handle

CheckoutConfig

On this page

`CheckoutConfig`