---
title: "POST /agent-commerce/ucp/checkout-sessions/{id}/complete"
method: POST
path: "/agent-commerce/ucp/checkout-sessions/{id}/complete"
---

# POST /agent-commerce/ucp/checkout-sessions/{id}/complete

`POST /agent-commerce/ucp/checkout-sessions/{id}/complete`

## Request

- Base URL: `https://mondoir.art`
- URL: `https://mondoir.art/agent-commerce/ucp/checkout-sessions/{id}/complete`
- Auth: HTTP bearer
- TypeScript: <https://skmtc.dev/mondoir/apis/mondoir-api/docs/agent-commerce/ucp/checkout-sessions/:id/complete/post.ts> (a function with typed inputs; its response is checked against the schema)

Negotiate x402 or MPP, then submit one signed proof; HTTP 202 means do not repay.

## Path parameters

- `id` string, uuid, required

## Request body

- object
  - `buyer` object
    - `email` string, email
    - `first_name` string
    - `last_name` string
    - `full_name` string
    - `phone_number` string
  - `payment_data` union
    - object
      - `handler_id` 'mondoir-usdc', required
      - `instrument` object, required
        - `type` 'wallet', required
        - `credential` object, required
          - `type` 'x402' | 'mpp', required
          - `token` string, required
    - object
      - `type` 'wallet', required
      - `credential` object, required
        - `type` 'x402' | 'mpp', required
        - `token` string, required
      - `id` string, required
      - `handler_id` 'mondoir-usdc', required

## Response `200`

Actual completed order.

## Other responses

- `202`: Recovery pending; do not repay.
- `402`: Real quote-bound payment challenge.

## Changes

- **2026-11-09** `5c50dd5066f8`: 1 breaking
  - added the pattern `^(?:[A-Za-z0-9_'+\-]+\.)*[A-Za-z0-9_'+\-]*[A-Za-z0-9_+-]@(?:[A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$` to the request property `buyer/email`
- **2026-10-18** `4990dc8b3ef4`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/mondoir/apis/mondoir-api/changes/agent-commerce/ucp/checkout-sessions/:id/complete/post.md)

---

[API](https://skmtc.dev/mondoir/apis/mondoir-api.md) - [All operations](https://skmtc.dev/mondoir/apis/mondoir-api/llms.txt) - [OpenAPI document](https://skmtc.dev/mondoir/apis/mondoir-api/revisions/5c50dd5066f8?raw)