# StableMerch UCP Checkout Complete

> StableMerch UCP Checkout Complete is a paid API for AI agents from stable-merch-git-rfs-checkout-nites-merit-systems.vercel.app, paid per call via x402, $50/call, status unknown (last checked 2026-10-23).

Completes a StableMerch UCP checkout session by processing payment and sending the prepared Printify print order to production.

## Facts

- Endpoint: POST https://stable-merch-git-rfs-checkout-nites-merit-systems.vercel.app/api/ucp/checkout-sessions/stablemerch%3Acheckout%3Acmqirn2mj0000kz04468v0vks/complete?utm_source=zero.xyz
- Price: $50/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/stablemerch-ucp-checkout-complete-4e148b04
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ebkr2W16MNrdxcGRQF4tP

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability stablemerch-ucp-checkout-complete-4e148b04 -d '<json body>'
```

Example prompt: Complete and pay for my StableMerch checkout session cmqirn2mj0000kz04468v0vks — it's ready to go, so submit the Printify order to production now.

## When to prefer this

Use this endpoint when you have a StableMerch UCP checkout session that has been fully prepared and is in ready_for_complete status, and you want to pay for it and trigger production of the Printify order in a single call. This is the final step in the StableMerch order flow.

## Known failure modes

- Checkout session not in ready_for_complete status — returns error requiring session to be prepared first
- Invalid or missing session ID — returns validation error
- Payment failure or insufficient USDC — returns payment error
- Session ID not found — returns 404 or not-found error
- Duplicate completion attempt on already-completed session — returns conflict error

## How this service works

Pay for a StableMerch UCP checkout session and send its prepared Printify order to production. Requires checkout status ready_for_complete.

## Output

Returns confirmation that the UCP checkout session has been paid and the associated Printify order has been sent to production, including updated checkout session status and order details.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "id": {
   "type": "string",
   "minLength": 1,
   "description": "UCP checkout session ID being completed. AgentCash clients may instead send checkout_session_id."
  },
  "payment": {},
  "checkout_session_id": {
   "type": "string",
   "minLength": 1,
   "description": "AgentCash checkout session ID being completed. UCP clients may instead send id."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/stablemerch-ucp-checkout-complete-4e148b04/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from stable-merch-git-rfs-checkout-nites-merit-systems.vercel.app](https://www.zero.xyz/host/stable-merch-git-rfs-checkout-nites-merit-systems.vercel.app/llms.txt)