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Live invoice PDF API

Invoice PDF generation for SaaS apps and developer tools.

Velentor helps SaaS builders and developers turn JSON invoice data into clean, branded PDF invoices. Send customer details, line items, tax, notes, and due dates. Get a professional PDF back from one API request.

View Sample Invoice Read API Docs
PDF Generated output
JSON Simple input
API Key Protected endpoint 
{
  "businessName": "Velentor",
  "customer": "Northstar Creative Studio",
  "invoiceNumber": "INV-SAMPLE-001",
  "date": "2026-07-04",
  "dueDate": "2026-07-18",
  "taxRate": 0.08,
  "items": [
    {
      "description": "Website Design Package",
      "quantity": 1,
      "price": 1200
    },
    {
      "description": "Brand Identity Refresh",
      "quantity": 1,
      "price": 650
    }
  ]
}
Features

Built for apps that need invoice generation.

Velentor handles PDF layout, totals, validation, and invoice formatting so your SaaS app or developer tool can focus on the product experience.

01

Professional layout

Generate branded invoices with customer info, invoice metadata, item tables, totals, notes, and footer details.

02

Automatic calculations

Send item prices, quantities, and tax rate. Velentor calculates subtotal, tax, and final total.

03

Protected API access

The PDF generation endpoint requires an API key through the x-api-key request header.

Sample Output

Preview the invoice your app can generate.

This sample shows the kind of branded invoice PDF your SaaS app, client portal, or internal tool can generate through Velentor.

Sample Invoice PDF
Generated from structured JSON data
Open PDF
API Docs

Simple API docs for developers.

Send invoice data as JSON. Velentor validates the request, calculates totals, and returns a downloadable PDF invoice for your app.

Endpoint Details

Base URL https://velentorapi.com
Generate PDF POST /invoice/pdf
Status Check GET /health
Authentication x-api-key: YOUR_API_KEY
Never expose your real API key in public frontend code, GitHub, screenshots, or client-side JavaScript. 
POST /invoice/pdf
Content-Type: application/json
x-api-key: YOUR_API_KEY

{
  "businessName": "Velentor",
  "customer": "Northstar Creative Studio",
  "customerEmail": "billing@northstarcreative.com",
  "invoiceNumber": "INV-SAMPLE-001",
  "date": "2026-07-04",
  "dueDate": "2026-07-18",
  "taxRate": 0.08,
  "items": [
    {
      "description": "Website Design Package",
      "quantity": 1,
      "price": 1200
    }
  ]
}

Request Body Fields

Field Type Required Description
businessName string No The business name shown on the invoice. Defaults to Velentor.
customer string No The customer or company receiving the invoice.
customerEmail string No The customer billing email shown on the invoice.
invoiceNumber string No The invoice number. If missing, Velentor creates a fallback invoice number.
date string No The invoice issue date.
dueDate string No The invoice payment due date.
taxRate number No Tax rate as a decimal. Example: 0.08 means 8%.
notes string No Optional payment notes or thank-you message.
items array Yes Line items for the invoice. Must include at least one item.
items[].description string No Description of the product or service.
items[].quantity number Yes Must be greater than 0.
items[].price number Yes Must be 0 or greater. 
$body = @{
  businessName = "Velentor"
  customer = "Northstar Creative Studio"
  customerEmail = "billing@northstarcreative.com"
  invoiceNumber = "INV-SAMPLE-001"
  date = "2026-07-04"
  dueDate = "2026-07-18"
  taxRate = 0.08
  notes = "Thank you for choosing Velentor."
  items = @(
    @{
      description = "Website Design Package"
      quantity = 1
      price = 1200
    },
    @{
      description = "Brand Identity Refresh"
      quantity = 1
      price = 650
    }
  )
} | ConvertTo-Json -Depth 5

Invoke-WebRequest -Uri "https://velentorapi.com/invoice/pdf" `
  -Method POST `
  -ContentType "application/json" `
  -Headers @{ "x-api-key" = "YOUR_API_KEY" } `
  -Body $body `
  -OutFile "invoice.pdf"
const response = await fetch(
  "https://velentorapi.com/invoice/pdf",
  {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-key": "YOUR_API_KEY"
    },
    body: JSON.stringify({
      businessName: "Velentor",
      customer: "Northstar Creative Studio",
      invoiceNumber: "INV-SAMPLE-001",
      taxRate: 0.08,
      items: [
        {
          description: "Website Design Package",
          quantity: 1,
          price: 1200
        }
      ]
    })
  }
);

const invoiceBlob = await response.blob();

Responses and Errors

200 OK Returns a downloadable PDF invoice.
400 Bad Request The request body is missing required invoice data or contains invalid values.
401 Unauthorized The API key is missing or invalid.
413 Payload Too Large The JSON request body is larger than the allowed limit.
429 Too Many Requests The invoice endpoint rate limit has been reached.
500 Server Error The server encountered an unexpected problem.
Pricing

Planned pricing for SaaS builders and developers.

Velentor is currently in MVP testing. Planned tiers are designed for developers, SaaS builders, client portals, and internal tools that need invoice PDF generation.

Starter

Developer

For testing Velentor inside small apps, prototypes, and internal tools.

$9/mo
  • Up to 250 invoices per month
  • API key access
  • Branded PDF output
  • Basic validation errors
Best for solo builders and early prototypes.
Most likely

Growth

For SaaS builders and small teams that need reliable invoice PDF generation.

$29/mo
  • Up to 2,000 invoices per month
  • API key access
  • Branded PDF output
  • Rate-limited production endpoint
  • Email support during beta
Best fit for small SaaS products and client portals.
Scale

Business

For teams with higher usage, custom invoice templates, or integration needs.

$79/mo
  • Up to 10,000 invoices per month
  • Higher rate limits
  • Custom branding options
  • Priority support
Best for production workflows with higher volume.

Building an app that needs invoice PDFs?

Request early access if you are building a SaaS app, client portal, internal tool, or developer workflow that needs branded invoice PDF generation.

Request Early Access