curl --request POST \
  --url https://api.creem.io/v1/subscriptions/{id}/upgrade \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "product_id": "prod_123",
  "update_behavior": "proration-charge-immediately"
}
'

import requests

url = "https://api.creem.io/v1/subscriptions/{id}/upgrade"

payload = {
    "product_id": "prod_123",
    "update_behavior": "proration-charge-immediately"
}
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({product_id: 'prod_123', update_behavior: 'proration-charge-immediately'})
};

fetch('https://api.creem.io/v1/subscriptions/{id}/upgrade', 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.creem.io/v1/subscriptions/{id}/upgrade",
  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([
    'product_id' => 'prod_123',
    'update_behavior' => 'proration-charge-immediately'
  ]),
  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.creem.io/v1/subscriptions/{id}/upgrade"

	payload := strings.NewReader("{\n  \"product_id\": \"prod_123\",\n  \"update_behavior\": \"proration-charge-immediately\"\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.creem.io/v1/subscriptions/{id}/upgrade")
  .header("x-api-key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"product_id\": \"prod_123\",\n  \"update_behavior\": \"proration-charge-immediately\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.creem.io/v1/subscriptions/{id}/upgrade")

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  \"product_id\": \"prod_123\",\n  \"update_behavior\": \"proration-charge-immediately\"\n}"

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

{
  "id": "<string>",
  "mode": "test",
  "object": "subscription",
  "product": {
    "id": "<string>",
    "mode": "test",
    "object": "<string>",
    "name": "<string>",
    "description": "This is a sample product description.",
    "price": 400,
    "currency": "USD",
    "billing_type": "recurring",
    "billing_period": "every-month",
    "status": "active",
    "tax_mode": "inclusive",
    "tax_category": "saas",
    "created_at": "2023-01-01T00:00:00Z",
    "updated_at": "2023-01-01T00:00:00Z",
    "image_url": "https://example.com/image.jpg",
    "image_urls": [
      "https://example.com/image.jpg"
    ],
    "features": [
      {
        "id": "feat_abc123",
        "type": "licenseKey",
        "description": "Access to premium course materials."
      }
    ],
    "recurring_interval": "month",
    "recurring_interval_count": 3,
    "product_url": "https://creem.io/product/prod_123123123123",
    "default_success_url": "https://example.com/?status=successful",
    "custom_fields": [
      {
        "type": "text",
        "key": "<string>",
        "label": "<string>",
        "optional": true,
        "text": {
          "max_length": 123,
          "minimum_length": 123,
          "value": "<string>"
        },
        "checkbox": {
          "label": "<string>",
          "value": true
        }
      }
    ]
  },
  "customer": {
    "id": "<string>",
    "mode": "test",
    "object": "<string>",
    "email": "user@example.com",
    "country": "US",
    "created_at": "2023-01-01T00:00:00Z",
    "updated_at": "2023-01-01T00:00:00Z",
    "name": "John Doe",
    "metadata": {
      "key": "value"
    }
  },
  "collection_method": "charge_automatically",
  "status": "active",
  "created_at": "2024-01-01T00:00:00Z",
  "updated_at": "2024-09-12T12:34:56Z",
  "items": [
    {
      "id": "<string>",
      "mode": "test",
      "object": "<string>",
      "product_id": "<string>",
      "price_id": "<string>",
      "units": 123
    }
  ],
  "last_transaction_id": "tran_3e6Z6TzvHKdsjEgXnGDEp0",
  "last_transaction": {
    "id": "<string>",
    "mode": "test",
    "object": "transaction",
    "amount": 2000,
    "currency": "USD",
    "type": "payment",
    "status": "pending",
    "created_at": 123,
    "amount_paid": 2000,
    "discount_amount": 2000,
    "tax_country": "US",
    "tax_amount": 2000,
    "refunded_amount": 2000,
    "order": "<string>",
    "subscription": "<string>",
    "customer": "<string>",
    "description": "<string>",
    "period_start": 123,
    "period_end": 123
  },
  "last_transaction_date": "2024-09-12T12:34:56Z",
  "next_transaction_date": "2024-09-12T12:34:56Z",
  "current_period_start_date": "2024-09-12T12:34:56Z",
  "current_period_end_date": "2024-09-12T12:34:56Z",
  "canceled_at": "2024-09-12T12:34:56Z",
  "discount": {
    "id": "dis_3e6Z6TzvHKdsjEgXnGDEp0",
    "discountCode": "HOLIDAY2024",
    "name": "<string>",
    "type": "percentage",
    "amount": 123,
    "duration": "forever",
    "durationInMonths": 123
  },
  "metadata": {
    "userId": "user_123",
    "plan": "pro"
  }
}