> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.crisscross.money/api-reference/collect/payments/manage-payments/cancel-session/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.crisscross.money/_mcp/server.

# Cancel a Session

POST https://api.crisscross.money/v1/checkout/session/cancel
Content-Type: application/json

Cancels a checkout session. The session is locked against any further payment attempts, and every in-flight (non-terminal) transaction linked to the session is cancelled in the same call. Transactions that have already reached a terminal state (settled, failed, refunded) are not affected.

If a transaction on the session is being processed by a provider that does not support cancelling an in-progress transaction, the session enters the **`PENDING_CANCELLATION`** state instead of `CANCELLED`. While in this state, no further payment attempts can be initiated against the session, but the session is not considered fully cancelled until the in-flight transaction reaches a terminal state on its own. The response will list the unstoppable transactions in `pendingTransactionIds`.


Reference: https://docs.crisscross.money/api-reference/collect/payments/manage-payments/cancel-session

## Request

### Body (application/json)

This endpoint expects a CancelSessionRequest.

- `sessionId` (string, required) — Identifier of the checkout session to cancel. UUID v7.
- `reason` (string, optional) — Optional free-form reason for the cancellation, recorded for reporting.

## Response

### 200

Session cancellation accepted.

- `sessionId` (string, required) — Identifier of the session that was cancelled. UUID v7.
- `status` (enum, required) — The resulting state of the session. `CANCELLED` indicates the session and all of its in-flight transactions have been cancelled. `PENDING_CANCELLATION` indicates the session is locked against further payment attempts, but at least one in-flight transaction belongs to a provider that does not support in-process cancellation — the session will move to `CANCELLED` once those transactions reach a terminal state.
  - Allowed values: `CANCELLED`, `PENDING_CANCELLATION`
- `message` (string, required) — Human-readable status message.
- `cancelledTransactionIds` (list of string, required) — Transactions on the session that were cancelled as part of this call. UUID v7.
- `pendingTransactionIds` (list of string, required) — Transactions still in flight that could not be cancelled because their provider does not support in-process cancellation. Populated only when `status` is `PENDING_CANCELLATION`. Each entry will progress to its own terminal state independently. UUID v7.

## Errors

### 400 Bad Request Error

Invalid request parameters.

- `message` (string, required) — Human-readable description of what went wrong.
- `error` (string, required) — Error category. Most endpoints return the HTTP reason phrase (e.g. "Bad Request", "Unauthorized", "Conflict", "Unprocessable Entity", "Internal Server Error"). Some return a machine-readable snake_case code instead — notably the FX and rate-lock rejections on checkout session creation and payment initiation, where several distinct codes share a single HTTP status. Where a code is present it is the finer discriminator and is safe to branch on.
- `statusCode` (integer, required) — HTTP status code, mirroring the response header. The response header is the source of truth.

### 401 Unauthorized Error

Unauthorized.

- `message` (string, required) — Human-readable description of what went wrong.
- `error` (string, required) — Error category. Most endpoints return the HTTP reason phrase (e.g. "Bad Request", "Unauthorized", "Conflict", "Unprocessable Entity", "Internal Server Error"). Some return a machine-readable snake_case code instead — notably the FX and rate-lock rejections on checkout session creation and payment initiation, where several distinct codes share a single HTTP status. Where a code is present it is the finer discriminator and is safe to branch on.
- `statusCode` (integer, required) — HTTP status code, mirroring the response header. The response header is the source of truth.

### 404 Not Found Error

Session not found.

- `message` (string, required) — Human-readable description of what went wrong.
- `error` (string, required) — Error category. Most endpoints return the HTTP reason phrase (e.g. "Bad Request", "Unauthorized", "Conflict", "Unprocessable Entity", "Internal Server Error"). Some return a machine-readable snake_case code instead — notably the FX and rate-lock rejections on checkout session creation and payment initiation, where several distinct codes share a single HTTP status. Where a code is present it is the finer discriminator and is safe to branch on.
- `statusCode` (integer, required) — HTTP status code, mirroring the response header. The response header is the source of truth.

### 409 Conflict Error

Conflict — the session is already cancelled or in a terminal state and cannot be cancelled again.

- `message` (string, required) — Human-readable description of what went wrong.
- `error` (string, required) — Error category. Most endpoints return the HTTP reason phrase (e.g. "Bad Request", "Unauthorized", "Conflict", "Unprocessable Entity", "Internal Server Error"). Some return a machine-readable snake_case code instead — notably the FX and rate-lock rejections on checkout session creation and payment initiation, where several distinct codes share a single HTTP status. Where a code is present it is the finer discriminator and is safe to branch on.
- `statusCode` (integer, required) — HTTP status code, mirroring the response header. The response header is the source of truth.

### 422 Unprocessable Entity Error

Unprocessable Entity.

- `message` (string, required) — Human-readable description of what went wrong.
- `error` (string, required) — Error category. Most endpoints return the HTTP reason phrase (e.g. "Bad Request", "Unauthorized", "Conflict", "Unprocessable Entity", "Internal Server Error"). Some return a machine-readable snake_case code instead — notably the FX and rate-lock rejections on checkout session creation and payment initiation, where several distinct codes share a single HTTP status. Where a code is present it is the finer discriminator and is safe to branch on.
- `statusCode` (integer, required) — HTTP status code, mirroring the response header. The response header is the source of truth.

## Examples

### Session fully cancelled

**Request**

```json
{
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "reason": "Customer abandoned checkout"
}
```

**Response**

```json
{
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "status": "CANCELLED",
  "message": "Session cancelled. 1 in-flight transaction was cancelled as part of this call.",
  "cancelledTransactionIds": [
    "01951c8a-8b4c-7d2a-8f1e-5d6c7b8a9e10"
  ],
  "pendingTransactionIds": []
}
```

**SDK Code**

```python Session fully cancelled
import requests

url = "https://api.crisscross.money/v1/checkout/session/cancel"

payload = {
    "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
    "reason": "Customer abandoned checkout"
}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript Session fully cancelled
const url = 'https://api.crisscross.money/v1/checkout/session/cancel';
const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: '{"sessionId":"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70","reason":"Customer abandoned checkout"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go Session fully cancelled
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.crisscross.money/v1/checkout/session/cancel"

	payload := strings.NewReader("{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby Session fully cancelled
require 'uri'
require 'net/http'

url = URI("https://api.crisscross.money/v1/checkout/session/cancel")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}"

response = http.request(request)
puts response.read_body
```

```java Session fully cancelled
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.crisscross.money/v1/checkout/session/cancel")
  .header("Content-Type", "application/json")
  .body("{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}")
  .asString();
```

```php Session fully cancelled
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.crisscross.money/v1/checkout/session/cancel', [
  'body' => '{
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "reason": "Customer abandoned checkout"
}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp Session fully cancelled
using RestSharp;

var client = new RestClient("https://api.crisscross.money/v1/checkout/session/cancel");
var request = new RestRequest(Method.POST);
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Session fully cancelled
import Foundation

let headers = ["Content-Type": "application/json"]
let parameters = [
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "reason": "Customer abandoned checkout"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.crisscross.money/v1/checkout/session/cancel")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```

### Session locked, waiting on an unstoppable transaction

**Request**

```json
{
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "reason": "Customer abandoned checkout"
}
```

**Response**

```json
{
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "status": "PENDING_CANCELLATION",
  "message": "Session locked. Awaiting terminal state on 1 in-flight transaction whose provider does not support in-process cancellation.",
  "cancelledTransactionIds": [
    "01951c8a-8b4c-7d2a-8f1e-5d6c7b8a9e10"
  ],
  "pendingTransactionIds": [
    "01951c8a-ad6f-7b1c-a2d3-7f8e9d0c1b32"
  ]
}
```

**SDK Code**

```python Session locked, waiting on an unstoppable transaction
import requests

url = "https://api.crisscross.money/v1/checkout/session/cancel"

payload = {
    "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
    "reason": "Customer abandoned checkout"
}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript Session locked, waiting on an unstoppable transaction
const url = 'https://api.crisscross.money/v1/checkout/session/cancel';
const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: '{"sessionId":"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70","reason":"Customer abandoned checkout"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go Session locked, waiting on an unstoppable transaction
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.crisscross.money/v1/checkout/session/cancel"

	payload := strings.NewReader("{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby Session locked, waiting on an unstoppable transaction
require 'uri'
require 'net/http'

url = URI("https://api.crisscross.money/v1/checkout/session/cancel")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}"

response = http.request(request)
puts response.read_body
```

```java Session locked, waiting on an unstoppable transaction
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.crisscross.money/v1/checkout/session/cancel")
  .header("Content-Type", "application/json")
  .body("{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}")
  .asString();
```

```php Session locked, waiting on an unstoppable transaction
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.crisscross.money/v1/checkout/session/cancel', [
  'body' => '{
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "reason": "Customer abandoned checkout"
}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp Session locked, waiting on an unstoppable transaction
using RestSharp;

var client = new RestClient("https://api.crisscross.money/v1/checkout/session/cancel");
var request = new RestRequest(Method.POST);
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"sessionId\": \"01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70\",\n  \"reason\": \"Customer abandoned checkout\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Session locked, waiting on an unstoppable transaction
import Foundation

let headers = ["Content-Type": "application/json"]
let parameters = [
  "sessionId": "01951c8a-7c3d-7e1f-9d4a-2b3c4d5e6f70",
  "reason": "Customer abandoned checkout"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.crisscross.money/v1/checkout/session/cancel")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```