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

# Payment requirements (402) for an open order



## OpenAPI

````yaml https://api.tozzecard.xyz/openapi.json get /merchant/orders/{id}/pay
openapi: 3.1.0
info:
  title: Tozzecard API
  version: 1.0.0
  description: >-
    Backend for the Tozzecard app: card sign-in, card face and statement, agent
    strategy, portfolio, agent feed, market hours and the demo B402 merchant.


    **Sign in with the card key** (the EOA the browser unlocks with the
    passkey):

    1. `POST /auth/challenge {address}` → `{message}`

    2. `account.signMessage({ message })` (viem)

    3. `POST /auth/verify {message, signature}` → `{token, address, kyc, card}`.

    4. Send `Authorization: Bearer <token>` on `/me*`, `/kyc/session` and `PUT
    /strategy`. Tokens last 30 days.


    **Activating the card** (identity check with Didit): while `kyc` is not
    `approved`, `card` is null. `POST /kyc/session {returnUrl?}` → `{url}`; open
    it; Didit sends the user back to `returnUrl`; poll `GET /me` while `kyc` is
    `pending`. On approval the card is issued with the holder name from the
    document.


    **Paying a merchant order** (B402 / x402 v2): `GET
    /merchant/orders/{id}/pay` → 402 with `accepts[0]`; build and sign with
    `@tozzecard/binance/eip3009` (`transferAuthorization`, `signTypedData`,
    `paymentHeader`); `POST` the same URL with header `PAYMENT-SIGNATURE`. The
    receipt comes back in `PAYMENT-RESPONSE`.


    Errors are `{error, code?}`. Amounts in USD are numbers; on-chain amounts
    are decimal strings.
servers:
  - url: https://api.tozzecard.xyz
    description: VPS (BSC mainnet)
  - url: http://localhost:8787
    description: Local
security: []
tags:
  - name: Card
    description: Sign-in and the card itself
  - name: Agent
    description: Strategy, portfolio and the agent's decisions
  - name: Market
    description: US market hours and tokenized stock prices
  - name: Merchant
    description: Demo merchant accepting USD1 through B402
  - name: System
paths:
  /merchant/orders/{id}/pay:
    get:
      tags:
        - Merchant
      summary: Payment requirements (402) for an open order
      parameters:
        - name: id
          in: path
          required: true
          schema:
            type: string
      responses:
        '200':
          description: Already paid
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Order'
        '402':
          description: Pay with accepts[0]
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PaymentRequired'
        '404':
          description: Unknown order
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    Order:
      type: object
      properties:
        id:
          type: string
        amount:
          type: string
          description: USD1 smallest unit (18 decimals)
        description:
          type: string
        status:
          enum:
            - open
            - paid
        payer:
          anyOf:
            - type: string
            - type: 'null'
        tx:
          anyOf:
            - type: string
            - type: 'null'
        createdAt:
          type: number
    PaymentRequired:
      type: object
      properties:
        x402Version:
          const: 2
        accepts:
          type: array
          items:
            type: object
            description: >-
              PaymentRequirements: pass accepts[0] unchanged to
              transferAuthorization
            properties:
              scheme:
                const: exact
              network:
                const: eip155:56
              amount:
                type: string
              asset:
                type: string
              payTo:
                type: string
              maxTimeoutSeconds:
                type: number
              extra:
                type: object
        error:
          type: string
    Error:
      type: object
      required:
        - error
      properties:
        error:
          type: string
        code:
          type: string

````

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