curl --request PUT \
  --url https://{tenant}/tyk/oauth/clients/{apiID}/{keyName} \
  --header 'Content-Type: application/json' \
  --header 'X-Tyk-Authorization: <api-key>' \
  --data '
{
  "api_id": "b84fe1a04e5648927971c0557971565c",
  "client_id": "2a06b398c17f46908de3dffcb71ef87df",
  "description": "changed description sample",
  "meta_data": {
    "user_id": "362b3fb9a1d5e4f00017226f5"
  },
  "redirect_uri": "https://httpbin.org/ip",
  "secret": "MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0"
}
'

import requests

url = "https://{tenant}/tyk/oauth/clients/{apiID}/{keyName}"

payload = {
    "api_id": "b84fe1a04e5648927971c0557971565c",
    "client_id": "2a06b398c17f46908de3dffcb71ef87df",
    "description": "changed description sample",
    "meta_data": { "user_id": "362b3fb9a1d5e4f00017226f5" },
    "redirect_uri": "https://httpbin.org/ip",
    "secret": "MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0"
}
headers = {
    "X-Tyk-Authorization": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'PUT',
  headers: {'X-Tyk-Authorization': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    api_id: 'b84fe1a04e5648927971c0557971565c',
    client_id: '2a06b398c17f46908de3dffcb71ef87df',
    description: 'changed description sample',
    meta_data: {user_id: '362b3fb9a1d5e4f00017226f5'},
    redirect_uri: 'https://httpbin.org/ip',
    secret: 'MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0'
  })
};

fetch('https://{tenant}/tyk/oauth/clients/{apiID}/{keyName}', 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://{tenant}/tyk/oauth/clients/{apiID}/{keyName}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PUT",
  CURLOPT_POSTFIELDS => json_encode([
    'api_id' => 'b84fe1a04e5648927971c0557971565c',
    'client_id' => '2a06b398c17f46908de3dffcb71ef87df',
    'description' => 'changed description sample',
    'meta_data' => [
        'user_id' => '362b3fb9a1d5e4f00017226f5'
    ],
    'redirect_uri' => 'https://httpbin.org/ip',
    'secret' => 'MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-Tyk-Authorization: <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://{tenant}/tyk/oauth/clients/{apiID}/{keyName}"

	payload := strings.NewReader("{\n  \"api_id\": \"b84fe1a04e5648927971c0557971565c\",\n  \"client_id\": \"2a06b398c17f46908de3dffcb71ef87df\",\n  \"description\": \"changed description sample\",\n  \"meta_data\": {\n    \"user_id\": \"362b3fb9a1d5e4f00017226f5\"\n  },\n  \"redirect_uri\": \"https://httpbin.org/ip\",\n  \"secret\": \"MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0\"\n}")

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

	req.Header.Add("X-Tyk-Authorization", "<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.put("https://{tenant}/tyk/oauth/clients/{apiID}/{keyName}")
  .header("X-Tyk-Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"api_id\": \"b84fe1a04e5648927971c0557971565c\",\n  \"client_id\": \"2a06b398c17f46908de3dffcb71ef87df\",\n  \"description\": \"changed description sample\",\n  \"meta_data\": {\n    \"user_id\": \"362b3fb9a1d5e4f00017226f5\"\n  },\n  \"redirect_uri\": \"https://httpbin.org/ip\",\n  \"secret\": \"MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://{tenant}/tyk/oauth/clients/{apiID}/{keyName}")

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

request = Net::HTTP::Put.new(url)
request["X-Tyk-Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"api_id\": \"b84fe1a04e5648927971c0557971565c\",\n  \"client_id\": \"2a06b398c17f46908de3dffcb71ef87df\",\n  \"description\": \"changed description sample\",\n  \"meta_data\": {\n    \"user_id\": \"362b3fb9a1d5e4f00017226f5\"\n  },\n  \"redirect_uri\": \"https://httpbin.org/ip\",\n  \"secret\": \"MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0\"\n}"

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

{
  "client_id": "2a06b398c17f46908de3dffcb71ef87df",
  "description": "changed description sample",
  "meta_data": {
    "user_id": "362b3fb9a1d5e4f00017226f5"
  },
  "redirect_uri": "https://httpbin.org/ip",
  "secret": "MmQwNTI5NGQtYjU0YS00NjMyLWIwZjktNTZjY2M1ZjhjYWY0"
}

{
  "message": "Policy access rights doesn't contain API this OAuth client belongs to",
  "status": "error"
}

{
  "message": "Attempted administrative access with invalid or missing key!",
  "status": "error"
}

{
  "message": "API doesn't exist",
  "status": "error"
}

{
  "message": "Unmarshalling failed",
  "status": "error"
}