curl --request POST \
  --url https://api.example.com/api/v1/invoices \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "customer": {
    "email": "john@example.com",
    "first_name": "John",
    "last_name": "Doe",
    "phone": "08012345678"
  },
  "line_items": [
    {
      "description": "Consulting services",
      "quantity": 2,
      "unit_price": 500
    }
  ],
  "currency": "USD",
  "tax_rate": 7.5,
  "discount_amount": 50,
  "due_date": "2026-07-01T00:00:00Z",
  "notes": "Thank you for your business.",
  "metadata": {
    "order_ref": "ord_123"
  }
}
'

import requests

url = "https://api.example.com/api/v1/invoices"

payload = {
    "customer": {
        "email": "john@example.com",
        "first_name": "John",
        "last_name": "Doe",
        "phone": "08012345678"
    },
    "line_items": [
        {
            "description": "Consulting services",
            "quantity": 2,
            "unit_price": 500
        }
    ],
    "currency": "USD",
    "tax_rate": 7.5,
    "discount_amount": 50,
    "due_date": "2026-07-01T00:00:00Z",
    "notes": "Thank you for your business.",
    "metadata": { "order_ref": "ord_123" }
}
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({
    customer: {
      email: 'john@example.com',
      first_name: 'John',
      last_name: 'Doe',
      phone: '08012345678'
    },
    line_items: [{description: 'Consulting services', quantity: 2, unit_price: 500}],
    currency: 'USD',
    tax_rate: 7.5,
    discount_amount: 50,
    due_date: '2026-07-01T00:00:00Z',
    notes: 'Thank you for your business.',
    metadata: {order_ref: 'ord_123'}
  })
};

fetch('https://api.example.com/api/v1/invoices', 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.example.com/api/v1/invoices",
  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([
    'customer' => [
        'email' => 'john@example.com',
        'first_name' => 'John',
        'last_name' => 'Doe',
        'phone' => '08012345678'
    ],
    'line_items' => [
        [
                'description' => 'Consulting services',
                'quantity' => 2,
                'unit_price' => 500
        ]
    ],
    'currency' => 'USD',
    'tax_rate' => 7.5,
    'discount_amount' => 50,
    'due_date' => '2026-07-01T00:00:00Z',
    'notes' => 'Thank you for your business.',
    'metadata' => [
        'order_ref' => 'ord_123'
    ]
  ]),
  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.example.com/api/v1/invoices"

	payload := strings.NewReader("{\n  \"customer\": {\n    \"email\": \"john@example.com\",\n    \"first_name\": \"John\",\n    \"last_name\": \"Doe\",\n    \"phone\": \"08012345678\"\n  },\n  \"line_items\": [\n    {\n      \"description\": \"Consulting services\",\n      \"quantity\": 2,\n      \"unit_price\": 500\n    }\n  ],\n  \"currency\": \"USD\",\n  \"tax_rate\": 7.5,\n  \"discount_amount\": 50,\n  \"due_date\": \"2026-07-01T00:00:00Z\",\n  \"notes\": \"Thank you for your business.\",\n  \"metadata\": {\n    \"order_ref\": \"ord_123\"\n  }\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.example.com/api/v1/invoices")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"customer\": {\n    \"email\": \"john@example.com\",\n    \"first_name\": \"John\",\n    \"last_name\": \"Doe\",\n    \"phone\": \"08012345678\"\n  },\n  \"line_items\": [\n    {\n      \"description\": \"Consulting services\",\n      \"quantity\": 2,\n      \"unit_price\": 500\n    }\n  ],\n  \"currency\": \"USD\",\n  \"tax_rate\": 7.5,\n  \"discount_amount\": 50,\n  \"due_date\": \"2026-07-01T00:00:00Z\",\n  \"notes\": \"Thank you for your business.\",\n  \"metadata\": {\n    \"order_ref\": \"ord_123\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.example.com/api/v1/invoices")

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  \"customer\": {\n    \"email\": \"john@example.com\",\n    \"first_name\": \"John\",\n    \"last_name\": \"Doe\",\n    \"phone\": \"08012345678\"\n  },\n  \"line_items\": [\n    {\n      \"description\": \"Consulting services\",\n      \"quantity\": 2,\n      \"unit_price\": 500\n    }\n  ],\n  \"currency\": \"USD\",\n  \"tax_rate\": 7.5,\n  \"discount_amount\": 50,\n  \"due_date\": \"2026-07-01T00:00:00Z\",\n  \"notes\": \"Thank you for your business.\",\n  \"metadata\": {\n    \"order_ref\": \"ord_123\"\n  }\n}"

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

{
  "success": false,
  "status": 400,
  "message": "Validation failed.",
  "timestamp": "2026-09-17T12:00:00.000Z",
  "errors": [
    "amount must not be less than 0"
  ]
}

{
  "success": false,
  "status": 400,
  "message": "Validation failed.",
  "timestamp": "2026-09-17T12:00:00.000Z",
  "errors": [
    "amount must not be less than 0"
  ]
}