curl --request POST \
  --url https://api.example.com/v1/invoices/{id}/cancel \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "reason": "Buyer cancelled the purchase order."
}
'

import requests

url = "https://api.example.com/v1/invoices/{id}/cancel"

payload = { "reason": "Buyer cancelled the purchase order." }
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({reason: 'Buyer cancelled the purchase order.'})
};

fetch('https://api.example.com/v1/invoices/{id}/cancel', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.example.com/v1/invoices/{id}/cancel",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'reason' => 'Buyer cancelled the purchase order.'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://api.example.com/v1/invoices/{id}/cancel"

	payload := strings.NewReader("{\n  \"reason\": \"Buyer cancelled the purchase order.\"\n}")

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

	req.Header.Add("X-API-Key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.example.com/v1/invoices/{id}/cancel")
  .header("X-API-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"reason\": \"Buyer cancelled the purchase order.\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.example.com/v1/invoices/{id}/cancel")

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

request = Net::HTTP::Post.new(url)
request["X-API-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"reason\": \"Buyer cancelled the purchase order.\"\n}"

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

{
  "id": "ckxinv042",
  "publicId": "ckpub042",
  "orgId": "ckorg001",
  "buyerId": "ckbuy001",
  "buyerEmail": "buyer@acme.com",
  "buyerName": "ACME Imports LLC",
  "sellerConnectedAccountId": "ckacc042",
  "sellerExternalId": "seller-42",
  "sellerName": "Fazenda Boa Vista",
  "status": "cancelled",
  "currency": "USD",
  "amount": "12500.00",
  "requestNetworkId": null,
  "paymentChain": "base",
  "paymentAddress": "0x5fbe…a91c",
  "dueDate": null,
  "expiresAt": null,
  "cancelReason": "Buyer cancelled the purchase order.",
  "pendingApproval": false,
  "buyerRef": null,
  "dueNumber": null,
  "exportContractRef": null,
  "incoterm": null,
  "portOfLoading": null,
  "feeBps": 50,
  "feeAmount": "62.50",
  "brlSettledAmount": null,
  "fxRateAtSettlement": null,
  "createdAt": "2026-06-30T12:00:00.000Z",
  "updatedAt": "2026-06-30T12:00:00.000Z",
  "lineItems": [
    {
      "id": "ckli001",
      "description": "Order #42 — green coffee, 18t",
      "quantity": "1",
      "unitPrice": "12500.00",
      "subtotal": "12500.00",
      "ncmCode": null,
      "originState": null
    }
  ],
  "timeline": [
    {
      "id": "ckev001",
      "invoiceId": "ckxinv042",
      "type": "created",
      "source": "caratuva",
      "externalEventId": null,
      "occurredAt": "2026-06-30T12:00:00.000Z"
    }
  ]
}