curl --request POST \
  --url https://api-options.sandbox.rails.xyz/v1/matching/orders/cancel \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "clientRequestId": "9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55",
  "cancel": {
    "orderId": "01JRQM8H5XYZABCDEFGHJKMNPQ",
    "contract": "BTC-7FEB26-100000-C"
  }
}
'

import requests

url = "https://api-options.sandbox.rails.xyz/v1/matching/orders/cancel"

payload = {
    "clientRequestId": "9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55",
    "cancel": {
        "orderId": "01JRQM8H5XYZABCDEFGHJKMNPQ",
        "contract": "BTC-7FEB26-100000-C"
    }
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    clientRequestId: '9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55',
    cancel: {orderId: '01JRQM8H5XYZABCDEFGHJKMNPQ', contract: 'BTC-7FEB26-100000-C'}
  })
};

fetch('https://api-options.sandbox.rails.xyz/v1/matching/orders/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-options.sandbox.rails.xyz/v1/matching/orders/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([
    'clientRequestId' => '9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55',
    'cancel' => [
        'orderId' => '01JRQM8H5XYZABCDEFGHJKMNPQ',
        'contract' => 'BTC-7FEB26-100000-C'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($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-options.sandbox.rails.xyz/v1/matching/orders/cancel"

	payload := strings.NewReader("{\n  \"clientRequestId\": \"9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55\",\n  \"cancel\": {\n    \"orderId\": \"01JRQM8H5XYZABCDEFGHJKMNPQ\",\n    \"contract\": \"BTC-7FEB26-100000-C\"\n  }\n}")

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

	req.Header.Add("Authorization", "Bearer <token>")
	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-options.sandbox.rails.xyz/v1/matching/orders/cancel")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"clientRequestId\": \"9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55\",\n  \"cancel\": {\n    \"orderId\": \"01JRQM8H5XYZABCDEFGHJKMNPQ\",\n    \"contract\": \"BTC-7FEB26-100000-C\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api-options.sandbox.rails.xyz/v1/matching/orders/cancel")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"clientRequestId\": \"9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55\",\n  \"cancel\": {\n    \"orderId\": \"01JRQM8H5XYZABCDEFGHJKMNPQ\",\n    \"contract\": \"BTC-7FEB26-100000-C\"\n  }\n}"

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

{
  "queued": true,
  "accepted": false,
  "body": "order queued, pending acceptance",
  "action": "cancel",
  "messageId": "1770000000000-0",
  "clientRequestId": "9f1c2c9e-3f4a-4a4e-9f10-2b7d3f2a1c55",
  "contract": "BTC-7FEB26-100000-C",
  "orderId": "01JRQM8H5XYZABCDEFGHJKMNPQ"
}

{
  "error": "orderId is required"
}

{
  "error": "unauthorized"
}

{
  "error": "read-only token cannot create orders"
}

{
  "error": "api rate limit exceeded"
}

{
  "error": "matching service unavailable"
}

{
  "error": "matching service timed out"
}