Bring your template
Write HTML and CSS. Save a reusable template from the Console.
JSON IN. PDF OUT.
Your data. A document.
Go from a JSON payload to a finished PDF. One API call. Your HTML templates. No document storage.
Start buildingBuilt for your stack. Designed to stay out of your way.
Request
curl --fail-with-body --request POST \ https://api.sysinvoice.com/v1/invoices/generate \ --header "Authorization: Bearer $SYSINVOICE_API_KEY" \ --header 'Content-Type: application/json' \ --header 'Accept: application/pdf' \ --data '{ "template_id": "tpl_your_invoice_template", "document_data": { "invoice_number": "INV-2026-001", "issued_at": "2026-11-10", "currency": "EUR", "line_items": [ { "description": "API integration", "qty": 1, "price": 240, "amount": "240.00" } ], "total": "240.00" }}' \ --output invoice.pdfExample only: set your API key and replace template_id with your saved template ID.
OutputA4 · PDF
FROM PAYLOAD TO PAPER
Three steps. One endpoint.
Keep your business logic. Let the API handle the document.
Send your JSON
Authenticate with an API key and pass your template_id and document_data.
Get your PDF
Receive PDF bytes in the response. Stream them straight to your application.
Stateless by design
Document payloads and generated PDFs are processed in memory, without document storage.
Your layout, your code
Use HTML and compiled Tailwind CSS. No proprietary document designer to learn.
An API, not another workflow
An HTTP request fits into your existing backend, queue or automation.
Less PDF plumbing. More building.
Start with the request above. Connect your own template when you are ready.