using RestSharp;


var options = new RestClientOptions("http://localhost:56350/api/v1/Agents/Contact/GetContactList");
var client = new RestClient(options);
var request = new RestRequest("");
request.AddJsonBody("[\n  123\n]", false);
var response = await client.PostAsync(request);

Console.WriteLine("{0}", response.Content);

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify([123])
};

fetch('http://localhost:56350/api/v1/Agents/Contact/GetContactList', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_PORT => "56350",
  CURLOPT_URL => "http://localhost:56350/api/v1/Agents/Contact/GetContactList",
  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([
    123
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

import requests

url = "http://localhost:56350/api/v1/Agents/Contact/GetContactList"

payload = [123]
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify([123])
};

fetch('http://localhost:56350/api/v1/Agents/Contact/GetContactList', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

[
  {
    "ContactId": 123,
    "Name": "<string>",
    "OrgNr": "<string>",
    "Department": "<string>",
    "URL": "<string>",
    "City": "<string>",
    "DirectPhone": "<string>",
    "AssociateId": 123,
    "CountryId": 123,
    "EmailAddress": "<string>",
    "Kananame": "<string>",
    "EmailAddressName": "<string>",
    "URLName": "<string>",
    "AssociateFullName": "<string>",
    "BusinessName": "<string>",
    "CategoryName": "<string>",
    "CountryName": "<string>",
    "Address": {
      "Wgs84Latitude": 123,
      "Wgs84Longitude": 123,
      "LocalizedAddress": [
        [
          {
            "Name": "<string>",
            "Value": "<string>",
            "Tooltip": "<string>",
            "Label": "<string>",
            "ValueLength": 123,
            "AddressType": "<string>",
            "TableRight": {
              "Mask": "<string>",
              "Reason": "<string>"
            },
            "FieldProperties": {}
          }
        ]
      ],
      "Street": {
        "AtypeIdx": "Unknown",
        "Address1": "<string>",
        "Address2": "<string>",
        "Address3": "<string>",
        "City": "<string>",
        "County": "<string>",
        "State": "<string>",
        "Zipcode": "<string>",
        "Formatted": "<string>"
      },
      "Postal": {
        "AtypeIdx": "Unknown",
        "Address1": "<string>",
        "Address2": "<string>",
        "Address3": "<string>",
        "City": "<string>",
        "County": "<string>",
        "State": "<string>",
        "Zipcode": "<string>",
        "Formatted": "<string>"
      },
      "Formatted": "<string>",
      "TableRight": {
        "Mask": "<string>",
        "Reason": "<string>"
      },
      "FieldProperties": {}
    },
    "FormattedAddress": "<string>",
    "FullName": "<string>",
    "IsOwnerContact": true,
    "ActiveErpLinks": 123,
    "Number1": "<string>",
    "Number2": "<string>",
    "TableRight": {
      "Mask": "<string>",
      "Reason": "<string>"
    },
    "FieldProperties": {}
  }
]