InvoiceFluid

Invoice API

Automate invoicing with the invoice API

Design an invoice template once, send JSON, and get a finished invoice PDF back — generate one invoice or thousands, with no rendering servers to operate.

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Generate an invoice PDF 
curl -X POST https://api.invoicefluid.com/v1/invoices/{id}/render \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "data": {
      "client_name": "Aster & Co.",
      "invoice_number": "INV-1042",
      "total": "$6,966.00"
    }
  }' --output invoice.pdf

Invoicing on autopilot

Template once, generate forever

Design your invoice layout once in the visual editor. The API fills it with your data and returns a finished PDF — your branding stays consistent on every invoice.

Send JSON, get a PDF

POST the invoice data (client, line items, totals) and receive a print-ready PDF in the response. No HTML, no rendering servers to run.

Built for volume

Generate one invoice or thousands. The rendering pipeline scales horizontally and stays fast under production load.

No-code & AI ready

Trigger invoice generation from your app, from no-code tools, or from AI agents — anywhere you can make an HTTP request.

FAQ

Frequently asked questions

How does the invoice API work? +

Design an invoice template in the editor, then POST its data as JSON to the render endpoint. The API merges your data into the template and returns a finished invoice PDF.

What does the API return? +

The raw PDF bytes (application/pdf) in the response — ready to store, email, or stream to a customer.

Do I need to run a rendering server? +

No. There is no headless browser or rendering infrastructure to operate — you call one HTTPS endpoint and get a PDF back.

Can I generate invoices in bulk? +

Yes — the API is built for high-volume invoicing, so you can generate one invoice or many from the same template.

Just need to make one invoice? +

Use the free online generator instead — no code required. Open the invoice generator

Start automating invoices

Get an API key and generate your first invoice PDF in minutes — 100 free per month.

Get your API key