curl --request PATCH \
  --url https://www.merchkit.com/api/v1/attributes/{key} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "entity_type": "product",
  "acceptable_values": "White Oak,Smoked Oak,Walnut,Ash"
}
'

import requests

url = "https://www.merchkit.com/api/v1/attributes/{key}"

payload = {
    "entity_type": "product",
    "acceptable_values": "White Oak,Smoked Oak,Walnut,Ash"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({entity_type: 'product', acceptable_values: 'White Oak,Smoked Oak,Walnut,Ash'})
};

fetch('https://www.merchkit.com/api/v1/attributes/{key}', 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://www.merchkit.com/api/v1/attributes/{key}",
  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([
    'entity_type' => 'product',
    'acceptable_values' => 'White Oak,Smoked Oak,Walnut,Ash'
  ]),
  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://www.merchkit.com/api/v1/attributes/{key}"

	payload := strings.NewReader("{\n  \"entity_type\": \"product\",\n  \"acceptable_values\": \"White Oak,Smoked Oak,Walnut,Ash\"\n}")

	req, _ := http.NewRequest("PATCH", 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.patch("https://www.merchkit.com/api/v1/attributes/{key}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"entity_type\": \"product\",\n  \"acceptable_values\": \"White Oak,Smoked Oak,Walnut,Ash\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://www.merchkit.com/api/v1/attributes/{key}")

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

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"entity_type\": \"product\",\n  \"acceptable_values\": \"White Oak,Smoked Oak,Walnut,Ash\"\n}"

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

{
  "data": {
    "id": "a3d81c22-5f6e-4b09-8d17-c40a92e5b613",
    "name": "Material",
    "key": "material",
    "data_type": "single_select_list",
    "tool": "manual",
    "entity_type": "product",
    "channel": null,
    "is_primary": false,
    "custom_instructions": null,
    "acceptable_values": "White Oak,Smoked Oak,Walnut",
    "default_value": null,
    "constraints": {},
    "source_attributes": null
  }
}

{
  "error": {
    "code": "validation_failed",
    "message": "Unknown attribute key(s): colour.",
    "documentation_url": "https://docs.merchkit.com/developers/errors#validation_failed",
    "is_retriable": false,
    "retry_after_seconds": null,
    "alternative_action": "List valid attribute keys via GET /v1/attributes?type=product.",
    "request_id": "req_01j9x2k8",
    "field_errors": [
      {
        "field": "colour",
        "issue": "not_a_defined_attribute"
      }
    ]
  }
}