Fax API & code examples

Code examples

curl -s https://mcpfax.de/api/v1/fax/send \
  -H "Authorization: Bearer $MCPFAX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "recipient_fax_number": "+49 30 1234567",
    "content": "# Hello\nThis is a test fax.",
    "idempotency_key": "order-4711"
  }'

import base64, os, uuid, requests

API = "https://mcpfax.de/api/v1"
H = {"Authorization": f"Bearer {os.environ['MCPFAX_API_KEY']}"}

doc = {
    "recipient_fax_number": "+49 30 1234567",
    "file_base64": base64.b64encode(open("invoice.pdf", "rb").read()).decode(),
    "file_name": "invoice.pdf",
}
quote = requests.post(f"{API}/fax/price", json=doc, headers=H).json()
print(quote["pages"], "page(s),", quote["currency"], quote["cost"])

fax = requests.post(f"{API}/fax/send", headers=H, json={
    **doc, "idempotency_key": str(uuid.uuid4()), "max_cost": quote["cost"]}).json()
print("Fax", fax["fax_id"], fax["status"])

import { randomUUID } from "node:crypto";

const API = "https://mcpfax.de/api/v1";
const headers = {
  Authorization: `Bearer ${process.env.MCPFAX_API_KEY}`,
  "Content-Type": "application/json",
};

const res = await fetch(`${API}/fax/send`, {
  method: "POST",
  headers,
  body: JSON.stringify({
    recipient_fax_number: "+49 30 1234567",
    file_url: "https://example.com/contract.pdf",
    idempotency_key: randomUUID(),
  }),
});
const fax = await res.json();
console.log(`Fax #${fax.fax_id}: ${fax.status}`);

<?php
$ch = curl_init('https://mcpfax.de/api/v1/fax/send');
curl_setopt_array($ch, [
    CURLOPT_POST           => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => [
        'Authorization: Bearer ' . getenv('MCPFAX_API_KEY'),
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode([
        'recipient_fax_number' => '+49 30 1234567',
        'file_base64'          => base64_encode(file_get_contents('letter.pdf')),
        'file_name'            => 'letter.pdf',
        'idempotency_key'      => bin2hex(random_bytes(16)),
    ]),
]);
$fax = json_decode(curl_exec($ch), true);
echo "Fax #{$fax['fax_id']}: {$fax['status']}\n";

Document sources (exactly one per fax): content (text or Markdown), file_base64 + file_name (PDF, DOCX, JPG, PNG, TXT; max. 15 MB) or file_url (public https URL).

✔ Good practice: check the cost with /fax/price first, always send a unique idempotency_key (retries never send twice), use max_cost as a safety limit and poll /fax/{id} until "delivered" or "failed". Failed faxes are refunded automatically.

Complete, runnable examples and client configurations: github.com/Ploetzeneder/mcpfax