Why Choose a Fakturoid API v3 Integration & Who This Is For

A robust Fakturoid API v3 integration lets you automate invoicing end-to-end—creating invoices and expenses, syncing clients (subjects), downloading PDFs, and reacting to events via webhooks.
It uses OAuth 2.0, paginated JSON endpoints under https://app.fakturoid.cz/api/v3, requires a custom User-Agent header, and includes rate-limit response headers so you can scale safely.

This service is for SMEs using Fakturoid in CZ/SK, agencies, SaaS vendors, and e-commerce stores on WordPress/WooCommerce that want reliable invoice automation, payment status syncing, and ERP-style workflows with minimal manual work.

What You’ll Get from a Fakturoid API v3 Integration (Deliverables)

• WordPress/WooCommerce Integration: issue invoices for orders, attach PDFs to emails, map VAT & totals, sync payment status, and push corrections.
• Custom PHP/Framework Apps: secure OAuth2, queued jobs with rate-limit backoff, retry handling, and structured logging.
• Subjects (Clients) Sync: create/update Fakturoid subjects from customer records with address & VAT fields (including delivery addresses).
• Webhooks: real-time updates when invoices are created, paid, overdue, etc., with exponential backoff handling for retries.
• PDF & Attachments: fetch invoice PDFs and push files into Fakturoid when needed.
• Documentation & Handover: environment variables, keys, and runbooks your team can own.

How the Fakturoid API v3 Integration Works (Key Concepts)

Base URL, Headers & Pagination for Your Fakturoid API v3 Integration

All endpoints are under https://app.fakturoid.cz/api/v3 and most include your account {slug} (e.g., /accounts/{slug}/invoices.json).
Requests must include a meaningful User-Agent (e.g., YourApp (admin@example.com)), use JSON, and paginated results return 40 records per page (use ?page=).

OAuth 2.0 Options in a Fakturoid API v3 Integration

Use Authorization Code Flow for multi-tenant apps (per-customer consent) or Client Credentials for single-account scripts/services. Access tokens expire in ~2 hours; refresh tokens are available in the auth-code flow. Include the token as Authorization: Bearer <token>.

Rate Limiting & Reliability

The API returns X-RateLimit-Policy and X-RateLimit headers indicating remaining requests and window; if you hit limits, you’ll see 429. We implement queued retries and exponential backoff to stay within quotas—critical for a stable Fakturoid API v3 integration.

Core Objects You’ll Use

• Subjects (Clients): company/contact info, VAT numbers, delivery addresses, payment terms, language, and email settings.
• Invoices: document types (invoice, proforma, correction, tax document, final invoice), status lifecycle, payment methods, lines, totals, URLs (HTML/PDF), and VAT modes.
• Webhooks: fire on invoice/expense/subject events; your endpoint must return 2xx within 30s or delivery retries up to 5 times will occur.

WooCommerce ↔ Fakturoid: What We Automate in a Fakturoid API v3 Integration

• On order paid: create invoice in Fakturoid (map subject, lines, VAT, currency & due date), get PDF URL, and store a link back on the order.
• On refund/cancellation: create correction where appropriate and update customer communication.
• Sync client profiles (subjects) with delivery addresses and VAT IDs for accurate documents.
• Listen to invoice_paid webhooks to mark orders complete or trigger fulfillment.

Explore our related guides:
WooCommerce Integration Services and
Complete Fakturoid API Guide.

Developer Snippets (PHP) for a Fakturoid API v3 Integration

Get an Access Token (Client Credentials)

// Server-side PHP example: obtain OAuth2 token (Client Credentials)
$clientId     = getenv('FAKTUROID_CLIENT_ID');
$clientSecret = getenv('FAKTUROID_CLIENT_SECRET');

$ch = curl_init('https://app.fakturoid.cz/api/v3/oauth/token');
curl_setopt_array($ch, [
  CURLOPT_POST => true,
  CURLOPT_HTTPHEADER => [
    'User-Agent: YourAppName (tech@yourdomain.com)',
    'Accept: application/json',
    'Content-Type: application/json',
    'Authorization: Basic ' . base64_encode($clientId . ':' . $clientSecret),
  ],
  CURLOPT_POSTFIELDS => json_encode(['grant_type' => 'client_credentials']),
  CURLOPT_RETURNTRANSFER => true,
]);

$res = curl_exec($ch);
if ($res === false) { throw new RuntimeException(curl_error($ch)); }
$data = json_decode($res, true);
$accessToken = $data['access_token'] ?? null; // expires in ~7200s

Create an Invoice via Fakturoid API v3 Integration

// Create a basic invoice (assumes you already created/fetched the subject)
$slug = getenv('FAKTUROID_ACCOUNT_SLUG'); // e.g. "applecorp"
$payload = [
  'subject_id' => 12345,
  'issued_on'  => date('Y-m-d'),
  'due'        => 14,
  'currency'   => 'CZK',
  'payment_method' => 'bank',
  'lines' => [
    [
      'name' => 'WooCommerce Order #1001',
      'quantity' => 1,
      'unit_name' => 'ks',
      'unit_price' => 1000.0,
      'vat_rate' => 21
    ]
  ],
];

$ch = curl_init("https://app.fakturoid.cz/api/v3/accounts/{$slug}/invoices.json");
curl_setopt_array($ch, [
  CURLOPT_POST => true,
  CURLOPT_HTTPHEADER => [
    'User-Agent: YourAppName (tech@yourdomain.com)',
    'Accept: application/json',
    'Content-Type: application/json',
    'Authorization: Bearer ' . $accessToken,
  ],
  CURLOPT_POSTFIELDS => json_encode($payload),
  CURLOPT_RETURNTRANSFER => true,
]);

$res = curl_exec($ch);
if ($res === false) { throw new RuntimeException(curl_error($ch)); }
$invoice = json_decode($res, true);
// $invoice['pdf_url'], $invoice['html_url'], $invoice['status'], etc.

Subjects (Clients): Create/Update

$payload = [
  'name' => 'ACME s.r.o.',
  'email' => 'billing@acme.cz',
  'street' => 'Vzorová 1',
  'city'   => 'Praha',
  'zip'    => '11000',
  'country'=> 'CZ',
  'vat_no' => 'CZ12345678',
  'has_delivery_address' => true,
  'delivery_name' => 'ACME Warehouse',
  'delivery_street' => 'Skladová 2',
  'delivery_city' => 'Praha',
  'delivery_zip' => '12000',
  'delivery_country' => 'CZ',
];

$ch = curl_init("https://app.fakturoid.cz/api/v3/accounts/{$slug}/subjects.json");
curl_setopt_array($ch, [
  CURLOPT_POST => true,
  CURLOPT_HTTPHEADER => [
    'User-Agent: YourAppName (tech@yourdomain.com)',
    'Accept: application/json',
    'Content-Type: application/json',
    'Authorization: Bearer ' . $accessToken,
  ],
  CURLOPT_POSTFIELDS => json_encode($payload),
  CURLOPT_RETURNTRANSFER => true,
]);
$res = curl_exec($ch);
$subject = json_decode($res, true);

Webhook Endpoint (Invoice Paid) in a Fakturoid API v3 Integration

// Minimal webhook receiver (e.g., in a WordPress endpoint or custom route)
$headers = getallheaders();
if (($headers['Authorization'] ?? '') !== 'Bearer YOUR_SHARED_TOKEN') {
  http_response_code(401);
  exit('Unauthorized');
}

$payload = json_decode(file_get_contents('php://input'), true);
$event = $payload['event_name'] ?? '';
if ($event === 'invoice_paid') {
  $invoice = $payload['body']['invoice'] ?? null;
  // TODO: mark related Woo order as completed, notify fulfillment, etc.
}

http_response_code(204); // acknowledge delivery quickly

Search Intents & Keywords We Cover (Fakturoid API v3 Integration)

Short-tail & long-tail phrases targeted here:

• Fakturoid API v3 integration, Fakturoid developer, Fakturoid consultant
• Fakturoid WordPress plugin, WooCommerce Fakturoid invoices, WooCommerce to Fakturoid
• Fakturoid OAuth2, Fakturoid webhooks, Fakturoid PHP SDK/integration
• Automate invoices Fakturoid, Fakturoid subjects API, Fakturoid expenses API
• Czech invoicing automation, CZ VAT invoices, custom accounting workflow automation

Implementation Process & Pricing for a Fakturoid API v3 Integration

1. Discovery: map your flows (orders → invoices, refunds → corrections, subject sync), stack, and compliance.
2. Architecture: select OAuth flow, design webhook handlers, queues, and rate-limit strategy with retries.
3. Build: WordPress plugin or custom PHP service with environment-first config, unit tests, and observability.
4. QA: sandbox/test accounts, pagination tests, error handling (422/429/5xx), and idempotent retries.
5. Handover: docs, runbooks, and training for your team.

Fakturoid API v3 Integration – FAQs

Is OAuth mandatory for a Fakturoid API v3 integration?

Yes—Fakturoid API v3 uses OAuth 2.0. Use Authorization Code for multi-tenant apps; use Client Credentials for your own account/services.

How are rate limits handled in a Fakturoid API v3 integration?

The API returns headers with remaining quota and reset window. If you hit limits you’ll get 429. We implement safe queues and backoff.

What invoice events can I subscribe to?

Common ones include invoice_created, invoice_paid, invoice_overdue, plus subject and expense events.

Can you create final invoices from proformas or tax documents?

Yes—the API supports document types (invoice, proforma, correction, tax document, final invoice) and proforma follow-ups; behavior is configurable.

Do you support multi-language invoices?

Yes, language can be set per document (cz, sk, en, de, fr, it, es, ru, pl, hu, ro).

Hire a Fakturoid API v3 Integration Expert

Ready to ship your integration? I’ll scope, build, and deploy a robust setup for WordPress, WooCommerce, or custom PHP—complete with OAuth2, webhooks, and fault-tolerant queues.

Hire me on Upwork → apiguru