JetPageInvoice generation
An invoice generator API where every total is exactly right
JetPage generates PDF invoices from one API call carrying a template id and JSON data, and computes every subtotal, tax line, and grand total with exact decimal arithmetic, so 0.1 + 0.2 equals 0.3 on a JetPage invoice, never 0.30000000000000004. JetPage typesets each invoice in tens of milliseconds on a real typesetting engine, formats currency and dates correctly for 10 locales, and renders every invoice tagged and accessible by default on every plan.
Why invoice math goes wrong, and what JetPage does instead
JetPage computes invoice totals with exact decimal arithmetic
Most software adds money with binary floating-point numbers, where 0.1 + 0.2 famously evaluates to 0.30000000000000004. On a report that is a curiosity; on an invoice that is a wrong total, and a wrong total on a tax document is a support ticket or worse. The JetPage formula engine does arithmetic in exact decimals, so the numbers on a JetPage invoice add up the way an accountant expects.
A team evaluating an invoice generator API should paste a real price list into each candidate and check the grand total; JetPage invites exactly that test.
JetPage totals whole line-item lists without loops or template code
An invoice is a list of line items plus derived numbers. In JetPage, the expression items.price reads the price of every line item at once, so a grand total is currency(sum(items.price)), written by picking fields and functions from a menu in the Inspector. The currency(), number(), and date() functions follow the locale of each render, covering 10 locales from en-US to de-DE to pt-BR.
With JetPage, the invoice template carries the billing logic, so the calling application sends raw line items and JetPage derives the totals, discounts, and taxes consistently on every render.
From one template to automated invoice generation at volume
JetPage validates invoice data against a schema before rendering anything
Automated invoice generation fails ugliest when bad data produces a plausible-looking wrong invoice. Every JetPage template declares the data shape it expects, such as customer_name as text or items as a list with qty and price, and JetPage validates every render request against that schema. Broken or incomplete data gets a precise field-by-field error, and no half-broken invoice PDF is ever produced.
Wiring an ERP or billing system to JetPage means integration errors surface as named fields in an error message, not as wrong invoices discovered by customers.
JetPage keeps bulk invoice generation fast, flat-priced, and accessible
Monthly billing runs multiply everything: render time, per-document cost, and compliance exposure. JetPage typesets one invoice in tens of milliseconds and sustains thousands of documents per second in bulk runs, bills one credit per invoice at any page count, and renders every invoice tagged and accessible by default, which matters for invoices under the European Accessibility Act.
A billing team can size a JetPage invoice run with one number, invoices per month, and gets compliance-ready output at that volume without an accessibility surcharge.
Frequently asked questions
Does JetPage provide an invoice generator API?
Yes. An application sends a template id and JSON invoice data to the JetPage render API and receives a link to the finished PDF in the same response, typically within a couple of seconds end to end, with the typesetting itself taking tens of milliseconds.
How does JetPage avoid rounding errors on invoices?
The JetPage formula engine computes with exact decimal arithmetic instead of binary floating point, so 0.1 + 0.2 equals exactly 0.3 and every subtotal, tax line, and grand total on a JetPage invoice adds up correctly.
Can JetPage generate invoices in bulk?
Yes. JetPage typesets one invoice in tens of milliseconds and sustains thousands of documents per second at volume, billing one credit per invoice regardless of page count. The JetPage bulk generation page documents the full speed and billing story.
Are JetPage invoices accessible?
Yes, by default. Every invoice JetPage renders is tagged and accessible on every plan, with alt text enforced at design time, at no extra cost. That default matters for invoices that fall under the European Accessibility Act.
Send JetPage a real invoice payload
JetPage is free to try without a credit card, and the free plan includes the render API, so a team can wire up a real invoice template and check every total before paying anything.