curl --request POST \
  --url https://api.railmail.app/api/v1/subscribers \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "email": "jane@example.com",
  "firstName": "Jane",
  "lastName": "Doe",
  "topicKeys": [
    "APIT-1",
    "APIT-2"
  ],
  "consent": {
    "source": "checkout-form",
    "sourceUrl": "https://shop.example.com/checkout",
    "ipAddress": "203.0.113.10",
    "userAgent": "Mozilla/5.0",
    "consentText": "I agree to receive product updates",
    "formVersion": "v3"
  },
  "customFields": {
    "plan": "pro"
  }
}
'

import requests

url = "https://api.railmail.app/api/v1/subscribers"

payload = {
    "email": "jane@example.com",
    "firstName": "Jane",
    "lastName": "Doe",
    "topicKeys": ["APIT-1", "APIT-2"],
    "consent": {
        "source": "checkout-form",
        "sourceUrl": "https://shop.example.com/checkout",
        "ipAddress": "203.0.113.10",
        "userAgent": "Mozilla/5.0",
        "consentText": "I agree to receive product updates",
        "formVersion": "v3"
    },
    "customFields": { "plan": "pro" }
}
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    email: 'jane@example.com',
    firstName: 'Jane',
    lastName: 'Doe',
    topicKeys: ['APIT-1', 'APIT-2'],
    consent: {
      source: 'checkout-form',
      sourceUrl: 'https://shop.example.com/checkout',
      ipAddress: '203.0.113.10',
      userAgent: 'Mozilla/5.0',
      consentText: 'I agree to receive product updates',
      formVersion: 'v3'
    },
    customFields: {plan: 'pro'}
  })
};

fetch('https://api.railmail.app/api/v1/subscribers', 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.railmail.app/api/v1/subscribers",
  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([
    'email' => 'jane@example.com',
    'firstName' => 'Jane',
    'lastName' => 'Doe',
    'topicKeys' => [
        'APIT-1',
        'APIT-2'
    ],
    'consent' => [
        'source' => 'checkout-form',
        'sourceUrl' => 'https://shop.example.com/checkout',
        'ipAddress' => '203.0.113.10',
        'userAgent' => 'Mozilla/5.0',
        'consentText' => 'I agree to receive product updates',
        'formVersion' => 'v3'
    ],
    'customFields' => [
        'plan' => 'pro'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-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.railmail.app/api/v1/subscribers"

	payload := strings.NewReader("{\n  \"email\": \"jane@example.com\",\n  \"firstName\": \"Jane\",\n  \"lastName\": \"Doe\",\n  \"topicKeys\": [\n    \"APIT-1\",\n    \"APIT-2\"\n  ],\n  \"consent\": {\n    \"source\": \"checkout-form\",\n    \"sourceUrl\": \"https://shop.example.com/checkout\",\n    \"ipAddress\": \"203.0.113.10\",\n    \"userAgent\": \"Mozilla/5.0\",\n    \"consentText\": \"I agree to receive product updates\",\n    \"formVersion\": \"v3\"\n  },\n  \"customFields\": {\n    \"plan\": \"pro\"\n  }\n}")

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

	req.Header.Add("X-API-Key", "<api-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.railmail.app/api/v1/subscribers")
  .header("X-API-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"email\": \"jane@example.com\",\n  \"firstName\": \"Jane\",\n  \"lastName\": \"Doe\",\n  \"topicKeys\": [\n    \"APIT-1\",\n    \"APIT-2\"\n  ],\n  \"consent\": {\n    \"source\": \"checkout-form\",\n    \"sourceUrl\": \"https://shop.example.com/checkout\",\n    \"ipAddress\": \"203.0.113.10\",\n    \"userAgent\": \"Mozilla/5.0\",\n    \"consentText\": \"I agree to receive product updates\",\n    \"formVersion\": \"v3\"\n  },\n  \"customFields\": {\n    \"plan\": \"pro\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.railmail.app/api/v1/subscribers")

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

request = Net::HTTP::Post.new(url)
request["X-API-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"email\": \"jane@example.com\",\n  \"firstName\": \"Jane\",\n  \"lastName\": \"Doe\",\n  \"topicKeys\": [\n    \"APIT-1\",\n    \"APIT-2\"\n  ],\n  \"consent\": {\n    \"source\": \"checkout-form\",\n    \"sourceUrl\": \"https://shop.example.com/checkout\",\n    \"ipAddress\": \"203.0.113.10\",\n    \"userAgent\": \"Mozilla/5.0\",\n    \"consentText\": \"I agree to receive product updates\",\n    \"formVersion\": \"v3\"\n  },\n  \"customFields\": {\n    \"plan\": \"pro\"\n  }\n}"

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

{
  "subscriberKey": "SUB-1A2B",
  "email": "jane@example.com",
  "firstName": "Jane",
  "lastName": "Doe",
  "phone": null,
  "status": "ACTIVE",
  "source": "API",
  "createdAt": "2026-06-24T10:15:00Z",
  "updatedAt": "2026-06-24T10:15:00Z"
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>",
  "timestamp": "2023-11-07T05:31:56Z",
  "errors": {}
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>",
  "timestamp": "2023-11-07T05:31:56Z",
  "errors": {}
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>",
  "timestamp": "2023-11-07T05:31:56Z",
  "errors": {}
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>",
  "timestamp": "2023-11-07T05:31:56Z",
  "errors": {}
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>",
  "timestamp": "2023-11-07T05:31:56Z",
  "errors": {}
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>",
  "timestamp": "2023-11-07T05:31:56Z",
  "errors": {}
}

{
  "type": "<string>",
  "title": "<string>",
  "status": 123,
  "detail": "<string>",
  "instance": "<string>",
  "timestamp": "2023-11-07T05:31:56Z",
  "errors": {}
}