---
title: "Cancel an ACP checkout session"
method: POST
path: "/checkout_sessions/{id}/cancel"
tags: ["Agentic Commerce (ACP) - demo"]
---

# Cancel an ACP checkout session

`POST /checkout_sessions/{id}/cancel`

Mark a checkout session cancel. DEMO-ONLY: canned responses, no real Forter risk decisioning, no real payment.

## Headers

- `API-Version` string, required
- `Idempotency-Key` string, required

## Response `200`

Success - demo ACP object.

- CheckoutSession — ACP checkout session (DEMO surface). Forter is a fraud-prevention platform and does not sell goods or take real payment - responses are canned demo objects.
  - `id` string
  - `object` 'checkout_session'
  - `status` 'open' | 'complete' | 'canceled'
  - `intent` object
  - `payment_methods` object[]
  - `fraud_decisioning` object — Demo Forter decision block. decision is one of APPROVE, DECLINE, VERIFICATION_REQUIRED, NOT_REVIEWED.
  - `idempotency_key` string, nullable
  - `livemode` boolean
  - `created` integer — Unix timestamp (seconds).

## Other responses

- `400` — Missing/unsupported header or malformed body - ACP-shaped error with supported_versions.
- `404` — Checkout session not found - ACP-shaped error.
- `405` — Method not allowed on this ACP endpoint - ACP-shaped error.
- `429` — Too Many Requests (The client exceeded a rate limit). Honor Retry-After before retrying.
- `default` — Typed ACP error.

---

[API](https://skmtc.net/forter/apis/forter-api.md) · [All operations](https://skmtc.net/forter/apis/forter-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/forter/forter-api/revisions/d7b02e919b34/schema)