curl --request POST \
  --url https://api-sandbox.circle.com/v1/payments/customers \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "refId": "310c458a-18eb-4cbd-8a9a-586d9448ae69",
  "type": "individual",
  "address": {
    "addressLine1": "123 Main St.",
    "city": "Boston",
    "postalCode": "02110",
    "country": "US",
    "addressLine2": "Apt 4B",
    "district": "MA"
  },
  "firstName": "John",
  "lastName": "Doe",
  "dateOfBirth": "1990-11-29",
  "placeOfBirth": "US",
  "governmentIssuedId": "A1234567"
}
'

import requests

url = "https://api-sandbox.circle.com/v1/payments/customers"

payload = {
    "refId": "310c458a-18eb-4cbd-8a9a-586d9448ae69",
    "type": "individual",
    "address": {
        "addressLine1": "123 Main St.",
        "city": "Boston",
        "postalCode": "02110",
        "country": "US",
        "addressLine2": "Apt 4B",
        "district": "MA"
    },
    "firstName": "John",
    "lastName": "Doe",
    "dateOfBirth": "1990-11-29",
    "placeOfBirth": "US",
    "governmentIssuedId": "A1234567"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    refId: '310c458a-18eb-4cbd-8a9a-586d9448ae69',
    type: 'individual',
    address: {
      addressLine1: '123 Main St.',
      city: 'Boston',
      postalCode: '02110',
      country: 'US',
      addressLine2: 'Apt 4B',
      district: 'MA'
    },
    firstName: 'John',
    lastName: 'Doe',
    dateOfBirth: '1990-11-29',
    placeOfBirth: 'US',
    governmentIssuedId: 'A1234567'
  })
};

fetch('https://api-sandbox.circle.com/v1/payments/customers', 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-sandbox.circle.com/v1/payments/customers",
  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([
    'refId' => '310c458a-18eb-4cbd-8a9a-586d9448ae69',
    'type' => 'individual',
    'address' => [
        'addressLine1' => '123 Main St.',
        'city' => 'Boston',
        'postalCode' => '02110',
        'country' => 'US',
        'addressLine2' => 'Apt 4B',
        'district' => 'MA'
    ],
    'firstName' => 'John',
    'lastName' => 'Doe',
    'dateOfBirth' => '1990-11-29',
    'placeOfBirth' => 'US',
    'governmentIssuedId' => 'A1234567'
  ]),
  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://api-sandbox.circle.com/v1/payments/customers"

	payload := strings.NewReader("{\n  \"refId\": \"310c458a-18eb-4cbd-8a9a-586d9448ae69\",\n  \"type\": \"individual\",\n  \"address\": {\n    \"addressLine1\": \"123 Main St.\",\n    \"city\": \"Boston\",\n    \"postalCode\": \"02110\",\n    \"country\": \"US\",\n    \"addressLine2\": \"Apt 4B\",\n    \"district\": \"MA\"\n  },\n  \"firstName\": \"John\",\n  \"lastName\": \"Doe\",\n  \"dateOfBirth\": \"1990-11-29\",\n  \"placeOfBirth\": \"US\",\n  \"governmentIssuedId\": \"A1234567\"\n}")

	req, _ := http.NewRequest("POST", 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.post("https://api-sandbox.circle.com/v1/payments/customers")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"refId\": \"310c458a-18eb-4cbd-8a9a-586d9448ae69\",\n  \"type\": \"individual\",\n  \"address\": {\n    \"addressLine1\": \"123 Main St.\",\n    \"city\": \"Boston\",\n    \"postalCode\": \"02110\",\n    \"country\": \"US\",\n    \"addressLine2\": \"Apt 4B\",\n    \"district\": \"MA\"\n  },\n  \"firstName\": \"John\",\n  \"lastName\": \"Doe\",\n  \"dateOfBirth\": \"1990-11-29\",\n  \"placeOfBirth\": \"US\",\n  \"governmentIssuedId\": \"A1234567\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api-sandbox.circle.com/v1/payments/customers")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"refId\": \"310c458a-18eb-4cbd-8a9a-586d9448ae69\",\n  \"type\": \"individual\",\n  \"address\": {\n    \"addressLine1\": \"123 Main St.\",\n    \"city\": \"Boston\",\n    \"postalCode\": \"02110\",\n    \"country\": \"US\",\n    \"addressLine2\": \"Apt 4B\",\n    \"district\": \"MA\"\n  },\n  \"firstName\": \"John\",\n  \"lastName\": \"Doe\",\n  \"dateOfBirth\": \"1990-11-29\",\n  \"placeOfBirth\": \"US\",\n  \"governmentIssuedId\": \"A1234567\"\n}"

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

{
  "data": {
    "id": "7d4f71c1-7e2e-4a1d-9df3-3a4d8d6d5a11",
    "refId": "310c458a-18eb-4cbd-8a9a-586d9448ae69",
    "type": "individual",
    "status": "pending",
    "firstName": "John",
    "lastName": "Doe",
    "dateOfBirth": "1990-11-29",
    "placeOfBirth": "US",
    "governmentIssuedId": "A1234567",
    "address": {
      "addressLine1": "123 Main St.",
      "addressLine2": "Apt 4B",
      "city": "Boston",
      "district": "MA",
      "postalCode": "02110",
      "country": "US"
    }
  }
}

{
  "code": 400,
  "message": "Bad request."
}

{
  "code": 401,
  "message": "Malformed authorization."
}

{
  "code": 3,
  "message": "Forbidden"
}

{
  "code": 409,
  "message": "Conflicts with another request."
}

{
  "code": 500,
  "message": "Internal server error."
}