curl --request POST \
  --url https://vas.finpaytech.co/business-api/api/v1/merchants/me/stk/initiate \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "phoneNumber": "254712345678",
  "amount": 2500,
  "expectedPaymentId": "721e86a8-fd29-49b5-b42f-67e19dfb2f6e"
}
'

import requests

url = "https://vas.finpaytech.co/business-api/api/v1/merchants/me/stk/initiate"

payload = {
    "phoneNumber": "254712345678",
    "amount": 2500,
    "expectedPaymentId": "721e86a8-fd29-49b5-b42f-67e19dfb2f6e"
}
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({
    phoneNumber: '254712345678',
    amount: 2500,
    expectedPaymentId: '721e86a8-fd29-49b5-b42f-67e19dfb2f6e'
  })
};

fetch('https://vas.finpaytech.co/business-api/api/v1/merchants/me/stk/initiate', 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://vas.finpaytech.co/business-api/api/v1/merchants/me/stk/initiate",
  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([
    'phoneNumber' => '254712345678',
    'amount' => 2500,
    'expectedPaymentId' => '721e86a8-fd29-49b5-b42f-67e19dfb2f6e'
  ]),
  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://vas.finpaytech.co/business-api/api/v1/merchants/me/stk/initiate"

	payload := strings.NewReader("{\n  \"phoneNumber\": \"254712345678\",\n  \"amount\": 2500,\n  \"expectedPaymentId\": \"721e86a8-fd29-49b5-b42f-67e19dfb2f6e\"\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://vas.finpaytech.co/business-api/api/v1/merchants/me/stk/initiate")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"phoneNumber\": \"254712345678\",\n  \"amount\": 2500,\n  \"expectedPaymentId\": \"721e86a8-fd29-49b5-b42f-67e19dfb2f6e\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://vas.finpaytech.co/business-api/api/v1/merchants/me/stk/initiate")

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  \"phoneNumber\": \"254712345678\",\n  \"amount\": 2500,\n  \"expectedPaymentId\": \"721e86a8-fd29-49b5-b42f-67e19dfb2f6e\"\n}"

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

{
  "id": "11111111-2222-3333-4444-555555555555",
  "merchantId": "301f0991-8f7c-4501-a1d4-c317fe7b7f23",
  "subMerchantId": null,
  "expectedPaymentId": "721e86a8-fd29-49b5-b42f-67e19dfb2f6e",
  "phoneNumber": "254712345678",
  "amount": 2500,
  "currency": "KES",
  "accountReference": "7600000073",
  "virtualAccountNumber": "7600000073",
  "inboundCreditId": null,
  "merchantRequestId": "ws_CO_09092026120000000",
  "checkoutRequestId": "ws_CO_09092026120000001",
  "status": "PENDING_CUSTOMER",
  "customerMessage": "Success. Request accepted for processing",
  "resultCode": null,
  "resultDesc": null,
  "mpesaReceiptNumber": null,
  "createdAt": "2026-09-09T12:00:00.000Z",
  "updatedAt": "2026-09-09T12:00:00.000Z"
}