curl --request GET \
  --url https://api.hubapi.com/commerce/contracts/2027-03-beta/contracts/{contractId}/changes

import requests

url = "https://api.hubapi.com/commerce/contracts/2027-03-beta/contracts/{contractId}/changes"

response = requests.get(url)

print(response.text)

const options = {method: 'GET'};

fetch('https://api.hubapi.com/commerce/contracts/2027-03-beta/contracts/{contractId}/changes', 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.hubapi.com/commerce/contracts/2027-03-beta/contracts/{contractId}/changes",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
]);

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

curl_close($curl);

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

package main

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

func main() {

	url := "https://api.hubapi.com/commerce/contracts/2027-03-beta/contracts/{contractId}/changes"

	req, _ := http.NewRequest("GET", url, nil)

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://api.hubapi.com/commerce/contracts/2027-03-beta/contracts/{contractId}/changes")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.hubapi.com/commerce/contracts/2027-03-beta/contracts/{contractId}/changes")

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

request = Net::HTTP::Get.new(url)

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

{
  "changes": [
    {
      "contractId": "<string>",
      "id": "<string>",
      "lineItemChanges": [
        {
          "action": "ADD",
          "rampKey": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
          "lineItemAdd": {
            "mode": "CUSTOM",
            "name": "<string>",
            "pricing": {
              "prices": [
                {
                  "currencyCode": "<string>",
                  "price": {},
                  "maxQuantity": 123
                }
              ],
              "pricingModel": "FLAT"
            },
            "quantity": 123,
            "allowBuyerSelectedQuantity": true,
            "billingCycleAnchorDate": "2023-12-25",
            "billingStartDelayDays": 123,
            "billingStartDelayMonths": 123,
            "buyerSelectedQuantityMax": 123,
            "buyerSelectedQuantityMin": 123,
            "description": "<string>",
            "discount": 123,
            "discountPercentage": 123,
            "externalId": "<string>",
            "images": "<string>",
            "isEditablePrice": true,
            "isOptional": true,
            "lineItemCurrencyCode": "<string>",
            "positionOnQuote": 123,
            "priceBookId": "<string>",
            "productId": "<string>",
            "productType": "<string>",
            "recurringBillingEndDate": "2023-12-25",
            "recurringBillingFrequency": "ANNUALLY",
            "recurringBillingPeriod": "<string>",
            "recurringBillingStartDate": "2023-12-25",
            "richTextDescription": "<string>",
            "sku": "<string>",
            "taxCategory": "<string>",
            "taxRateGroupId": "<string>",
            "variantId": "<string>"
          },
          "lineItemUpdate": {
            "allowBuyerSelectedQuantity": {},
            "billingCycleAnchorDate": {},
            "billingStartDelayDays": {},
            "billingStartDelayMonths": {},
            "buyerSelectedQuantityMax": {},
            "buyerSelectedQuantityMin": {},
            "description": {},
            "discount": {},
            "discountPercentage": {},
            "externalId": {},
            "images": {},
            "isEditablePrice": {},
            "isOptional": {},
            "lineItemCurrencyCode": {},
            "name": {},
            "positionOnQuote": {},
            "priceBookId": {},
            "pricing": {},
            "productType": {},
            "quantity": {},
            "recurringBillingEndDate": {},
            "recurringBillingFrequency": {},
            "recurringBillingPeriod": {},
            "recurringBillingStartDate": {},
            "richTextDescription": {},
            "sku": {},
            "taxCategory": {},
            "taxRateGroupId": {},
            "variantId": {}
          }
        }
      ],
      "prorating": true,
      "status": "ACCEPTED",
      "type": "DIRECT",
      "createdAt": "2023-11-07T05:31:56Z",
      "effectiveDate": "2023-12-25",
      "name": "<string>",
      "quoteId": "<string>",
      "updatedAt": "2023-11-07T05:31:56Z"
    }
  ]
}

{
  "message": "Invalid input (details will vary based on the error)",
  "correlationId": "aeb5f871-7f07-4993-9211-075dc63e7cbf",
  "category": "VALIDATION_ERROR",
  "links": {
    "knowledge-base": "https://www.hubspot.com/products/service/knowledge-base"
  }
}