## `POST /sop/:name/:id/cancel`

**Cancel an instance** — Terminates a running instance immediately. The instance moves to the `cancelled` state. Any pending steps are skipped. This action is irreversible.

> **Auth:** Requires `X-SOP-Token` header. See [Authentication](/api-docs/guides/authentication.md).

### Path parameters

- `name` (string, required) — The process name.
- `id` (string, required) — The instance ULID.

### Response

`200 application/json` — Instance in `cancelled` state.

```json
{
  "id":    "01HXYZ_ACME_001",
  "state": "cancelled"
}
```

### Errors

| Status | Code | Meaning |
|--------|------|---------|
| 404 | `not_found` | Instance does not exist. |
| 422 | `invalid_transition` | Instance is already in a terminal state. |

### Code examples

#### curl

```bash
curl https://api.opensop.dev/sop/customer-onboarding/01HXYZ_ACME_001/cancel \
  -X POST \
  -H "X-SOP-Token: $OPENSOP_TOKEN"
```

#### Node

```js
await fetch(
  `https://api.opensop.dev/sop/customer-onboarding/${id}/cancel`,
  {
    method: "POST",
    headers: { "X-SOP-Token": process.env.OPENSOP_TOKEN }
  }
);
```

#### Python

```python
requests.post(
  f"https://api.opensop.dev/sop/customer-onboarding/{instance_id}/cancel",
  headers={"X-SOP-Token": os.environ["OPENSOP_TOKEN"]}
)
```

#### Ruby

```ruby
req = Net::HTTP::Post.new("/sop/customer-onboarding/#{id}/cancel")
req["X-SOP-Token"] = ENV["OPENSOP_TOKEN"]
Net::HTTP.start("api.opensop.dev", use_ssl: true) { |h| h.request(req) }
```