curl --request POST \
  --url https://api.example.com/v1/transactions \
  --header 'Content-Type: application/json' \
  --header 'Idempotency-Key: <idempotency-key>' \
  --data '
{
  "referenceId": "PAY-123456",
  "postings": [
    {
      "source": "CUSTOMER:019bdb2a-960f-789d-8955-21720e6cdeee:019bdb2a-960f-789d-8955-21720e6cdeed:CURRENT",
      "destination": "INTERNAL:REVENUE:FEE",
      "currency": "EUR",
      "details": "Payment for invoice #67",
      "amount": 10000,
      "type": "CREDIT_TRANSFER"
    }
  ],
  "referenceSource": "CLIENT"
}
'

import requests

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

payload = {
    "referenceId": "PAY-123456",
    "postings": [
        {
            "source": "CUSTOMER:019bdb2a-960f-789d-8955-21720e6cdeee:019bdb2a-960f-789d-8955-21720e6cdeed:CURRENT",
            "destination": "INTERNAL:REVENUE:FEE",
            "currency": "EUR",
            "details": "Payment for invoice #67",
            "amount": 10000,
            "type": "CREDIT_TRANSFER"
        }
    ],
    "referenceSource": "CLIENT"
}
headers = {
    "Idempotency-Key": "<idempotency-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Idempotency-Key': '<idempotency-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    referenceId: 'PAY-123456',
    postings: [
      {
        source: 'CUSTOMER:019bdb2a-960f-789d-8955-21720e6cdeee:019bdb2a-960f-789d-8955-21720e6cdeed:CURRENT',
        destination: 'INTERNAL:REVENUE:FEE',
        currency: 'EUR',
        details: 'Payment for invoice #67',
        amount: 10000,
        type: 'CREDIT_TRANSFER'
      }
    ],
    referenceSource: 'CLIENT'
  })
};

fetch('https://api.example.com/v1/transactions', 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/v1/transactions",
  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([
    'referenceId' => 'PAY-123456',
    'postings' => [
        [
                'source' => 'CUSTOMER:019bdb2a-960f-789d-8955-21720e6cdeee:019bdb2a-960f-789d-8955-21720e6cdeed:CURRENT',
                'destination' => 'INTERNAL:REVENUE:FEE',
                'currency' => 'EUR',
                'details' => 'Payment for invoice #67',
                'amount' => 10000,
                'type' => 'CREDIT_TRANSFER'
        ]
    ],
    'referenceSource' => 'CLIENT'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "Idempotency-Key: <idempotency-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://api.example.com/v1/transactions"

	payload := strings.NewReader("{\n  \"referenceId\": \"PAY-123456\",\n  \"postings\": [\n    {\n      \"source\": \"CUSTOMER:019bdb2a-960f-789d-8955-21720e6cdeee:019bdb2a-960f-789d-8955-21720e6cdeed:CURRENT\",\n      \"destination\": \"INTERNAL:REVENUE:FEE\",\n      \"currency\": \"EUR\",\n      \"details\": \"Payment for invoice #67\",\n      \"amount\": 10000,\n      \"type\": \"CREDIT_TRANSFER\"\n    }\n  ],\n  \"referenceSource\": \"CLIENT\"\n}")

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

	req.Header.Add("Idempotency-Key", "<idempotency-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.post("https://api.example.com/v1/transactions")
  .header("Idempotency-Key", "<idempotency-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"referenceId\": \"PAY-123456\",\n  \"postings\": [\n    {\n      \"source\": \"CUSTOMER:019bdb2a-960f-789d-8955-21720e6cdeee:019bdb2a-960f-789d-8955-21720e6cdeed:CURRENT\",\n      \"destination\": \"INTERNAL:REVENUE:FEE\",\n      \"currency\": \"EUR\",\n      \"details\": \"Payment for invoice #67\",\n      \"amount\": 10000,\n      \"type\": \"CREDIT_TRANSFER\"\n    }\n  ],\n  \"referenceSource\": \"CLIENT\"\n}")
  .asString();

require 'uri'
require 'net/http'

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

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

request = Net::HTTP::Post.new(url)
request["Idempotency-Key"] = '<idempotency-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"referenceId\": \"PAY-123456\",\n  \"postings\": [\n    {\n      \"source\": \"CUSTOMER:019bdb2a-960f-789d-8955-21720e6cdeee:019bdb2a-960f-789d-8955-21720e6cdeed:CURRENT\",\n      \"destination\": \"INTERNAL:REVENUE:FEE\",\n      \"currency\": \"EUR\",\n      \"details\": \"Payment for invoice #67\",\n      \"amount\": 10000,\n      \"type\": \"CREDIT_TRANSFER\"\n    }\n  ],\n  \"referenceSource\": \"CLIENT\"\n}"

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

{
  "correlationId": "550e8400-e29b-41d4-a716-446655440000"
}

{
  "status": 400,
  "title": "<string>",
  "instance": "<string>",
  "violations": [
    {
      "field": "<string>",
      "message": "<string>"
    }
  ]
}

{
  "status": 500,
  "title": "<string>",
  "instance": "<string>",
  "detail": "<string>"
}