n8n: trigger SMS via Openapi from an automated workflow

[francescobianco]

Use case

We use n8n to orchestrate customer notifications. One step requires sending an SMS via Openapi when a form is submitted. Currently we call a custom PHP endpoint that wraps the SDK, but it feels like unnecessary infrastructure.

Current architecture

n8n Webhook → HTTP Request → PHP endpoint → Openapi SDK → SMS API

The PHP endpoint looks like:

<?php
require 'vendor/autoload.php';
use Openapi\Client;

$body = json_decode(file_get_contents('php://input'), true);
$client = new Client(getenv('OPENAPI_TOKEN'));
echo $client->post('https://sms.openapi.com/send', [
    'to'   => $body['phone'],
    'text' => $body['message'],
]);

Ideal state

A Docker-composable PHP microservice (or even a standalone FrankenPHP single binary) that exposes this pattern, so n8n can call it without deploying a full PHP app.

Open questions

• Would the project consider shipping a docker-compose.yml example for this pattern?
• Is FrankenPHP a reasonable target for a zero-config deployment story?
• Should the microservice handle token generation internally, or require the consumer to pass a pre-generated token?