curl --request PATCH \
  --url https://api.otark.energy/v1/customers/{customer_id} \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '
{
  "metadata": {
    "customer_number": "KD-2026-0815",
    "cost_center": "CC-4200"
  }
}
'

import requests

url = "https://api.otark.energy/v1/customers/{customer_id}"

payload = { "metadata": {
        "customer_number": "KD-2026-0815",
        "cost_center": "CC-4200"
    } }
headers = {
    "X-Api-Key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PATCH',
  headers: {'X-Api-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({metadata: {customer_number: 'KD-2026-0815', cost_center: 'CC-4200'}})
};

fetch('https://api.otark.energy/v1/customers/{customer_id}', 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.otark.energy/v1/customers/{customer_id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'metadata' => [
        'customer_number' => 'KD-2026-0815',
        'cost_center' => 'CC-4200'
    ]
  ]),
  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.otark.energy/v1/customers/{customer_id}"

	payload := strings.NewReader("{\n  \"metadata\": {\n    \"customer_number\": \"KD-2026-0815\",\n    \"cost_center\": \"CC-4200\"\n  }\n}")

	req, _ := http.NewRequest("PATCH", 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.patch("https://api.otark.energy/v1/customers/{customer_id}")
  .header("X-Api-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"metadata\": {\n    \"customer_number\": \"KD-2026-0815\",\n    \"cost_center\": \"CC-4200\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.otark.energy/v1/customers/{customer_id}")

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

request = Net::HTTP::Patch.new(url)
request["X-Api-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"metadata\": {\n    \"customer_number\": \"KD-2026-0815\",\n    \"cost_center\": \"CC-4200\"\n  }\n}"

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

{
  "id": "cust_r8s9t0u1",
  "name": "SolarDach GmbH",
  "status": "active",
  "balance_group": {
    "eic": "11YSOLARDACH--A",
    "tso": "DE_AMPRION"
  },
  "metadata": {
    "customer_number": "KD-2026-0815",
    "cost_center": "CC-4200",
    "region": "NRW"
  },
  "assigned_at": "2026-01-10T09:00:00Z",
  "created_at": "2026-01-10T09:00:00Z",
  "activated_at": "2026-01-10T11:30:00Z"
}

{
  "type": "https://brp.otark.team/errors/validation",
  "title": "Validation Failed",
  "status": 400,
  "instance": "/v1/customers/cust_r8s9t0u1",
  "errors": [
    {
      "field": "balance_group.tso",
      "code": "invalid_enum_value",
      "message": "Invalid enum value. Expected 'DE_AMPRION' | 'DE_TENNET' | 'DE_TRANSNET_BW' | 'DE_50HERTZ', received 'INVALID'"
    }
  ]
}

{
  "type": "https://brp.otark.team/errors/invalid_api_key",
  "title": "Invalid API Key",
  "status": 401
}

{
  "type": "https://brp.otark.team/errors/insufficient_scopes",
  "title": "Insufficient API Key Scopes",
  "status": 403,
  "detail": "Missing scope: customers:write. Please create a new API key with the required scopes."
}

{
  "type": "https://brp.otark.team/errors/customer_not_found",
  "title": "Customer Not Found",
  "status": 404,
  "instance": "/v1/customers/cust_r8s9t0u1"
}

{
  "type": "https://brp.otark.team/errors/already_active",
  "title": "Customer Already Active",
  "status": 409
}