Client_Id in Bitstamp's Api

Did you register for an API key via their instructions? They say:

To get an API key, go to "Account", "Security" and then "API Access". Set permissions and click "Generate key".`

Once you have the API key, you use a HMAC encoded of the API key, API secret, and your customer/client id. You should be able to get your client id by going to the "Account Balance" page, where I believe it's referred to as your "Customer ID".

Use this code to get idea. This is Ruby code

require 'open-uri'
require 'json'
require 'base64'
require 'openssl'
require 'hmac-sha2'
require 'net/http'
require 'net/https'
require 'uri'

def bitstamp_private_request(method, attrs = {})
  secret = "xxx"
  key = "xxx"
  client_id = "xxx"
  nonce = nonce_generator

  message = nonce + client_id + key
  signature = HMAC::SHA256.hexdigest(secret, message).upcase

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

  data = {
    nonce: nonce,
    key: key,
    signature: signature
  }
  data.merge!(attrs)
  data = data.map { |k,v| "#{k}=#{v}"}.join('&')

  headers = {
    'Content-Type' => 'application/x-www-form-urlencoded'
  }

  resp = http.post(url.path, data, headers)
  console_log ""
  resp.body
end

def nonce_generator
  (Time.now.to_f*1000).to_i.to_s
end

The page where you change password on Bitstamp presents you your client id (contains letters and digits).

I have some probelm with bitstamp api
below is my code php

$message = $nonce.$client_id.$api_key;

$signature = strtoupper(hash_hmac('sha256', $message, $secret_key));

$post_string = 'api_key='.$api_key.'&signature='.$signature.'&nonce='.$nonce;

$url = "";

$ch = curl_init();

curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch,CURLOPT_CONNECTTIMEOUT, 4);
curl_setopt($ch,CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_string);

$json = curl_exec($ch);

if(!$json) {
    echo curl_error($ch);
}

curl_close($ch);
$tempData = json_decode($json);

print_r($tempData);<br>

Output:

stdClass Object ( [error] => Missing key, signature and nonce parameters )