PDF Generator API

Generate the Document, Then Sign It, in One API

Most embedded-signing tools expect a finished PDF, or ask you to rebuild your document as a static template in their editor. PDF Generator API starts earlier: merge your data and templates into a finished, branded PDF, then open that same document in a guided review-and-sign flow. One platform takes you from raw data to a signed, audited document.

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One API for everything

Create, Review, Store

One developer platform covers the whole path, from raw data in your application to a signed, audited document, instead of wiring a document-generation service to a separate e-signature vendor. You build against one API and one set of credentials. We run the rendering, the viewer, the storage, and the audit trail on infrastructure that is ISO 27001 certified and GDPR compliant.

Explore document generation features

Drag-and-drop template editor, plus full HTML and CSS control
Merge JSON data from any system: CRM, ERP, HRIS, or your own app
Dynamic tables, conditional content, and an expression language for logic
Batch and asynchronous generation for high volume
The finished document flows straight into signing view
Long-term encrypted retention and bring-your-own-storage

Most signing APIs make you bring the document. This one builds it.

Embedded e-signature tools are built around the signature. You hand them a finished PDF, or rebuild your document as a static template in their editor, and they collect a signature on top. Producing the document is left to you.

PDF Generator API starts a step earlier. Design your template once in the drag-and-drop editor, or with your own HTML and CSS, then send JSON data through the API. We merge the data and template into a finished, branded PDF. Set output to viewer and that same document opens straight into the review-and-sign flow.

Explore document generation features

Stop building signing infrastructure! Let us do it!

Document signing looks simple until you start. You need a PDF renderer, a viewer that works on every device, signature capture, a place to store versions, audit logs, retention rules, and a compliance story your legal team will accept. That is weeks of work before you write a single line of the feature your users actually asked for.

Then it never stays finished. Someone needs the signer’s IP address for a dispute. A customer asks for every version of a contract. A regulator wants proof of who opened, reviewed, and signed a document, and when. Now you are maintaining an e-signature product you never meant to build.

PDF Generator API gives you the whole flow as an API. Generate the document or bring your own, and we handle the viewer, the signature capture, the versioning, and the audit trail. You get a URL, embed it, and ship.

Learn more about Security and Compliance

Stop building the document infrastructure

Embeddable Document Viewer

The signing and review experience is built into our Document Viewer. You reach it the same way every time, by asking for output=viewer, and you can feed it a document from whichever part of your workflow makes sense.

1. Generate a document, then sign it
Merge one of your templates with JSON data and set output to viewer. Instead of a file, you get a URL that opens the document straight into the review-and-sign flow.

View Document Generation API examples

2. Send a PDF you already have
Already generating PDFs somewhere else? Push an existing document to storage and get a review URL back. Provide either a public HTTPS file_url or a base64-encoded file_base64, and set output to viewer.

View Document Storage API examples

3. Collect data with a Web Form, then sign
Let your users fill in a form, generate the document from their answers, and drop them straight into the signing flow. Enable the Sign the document action on the form, and on submit the user is redirected into the review-and-sign experience automatically.

View Web Forms API examples

Create, Upload or Collect Web Form data for review flow

What is the embeddable document signing and review flow?

It is a hosted, ready-to-embed viewer that turns any PDF into a guided review-and-sign experience. You generate a document from a template, store an existing PDF, or collect one through a Web Form, and request output=viewer. The API returns a secure URL that walks the signer through their details, captures a typed, drawn, or uploaded signature, and confirms completion. In the background, PDF Generator API versions the document and records every action in an audit log. There is no signing UI to design, no viewer to maintain, and no separate e-signature vendor to integrate.

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Document versioning

Every signature and every review produces a new version of the document. Nothing is overwritten, so you always have the exact state of the agreement at each step: the original, the reviewed copy, and the fully executed version. Pull the full version history with the document’s public_id.

Audit logs

Every interaction with a document is recorded: opened, reviewed, accepted, declined, commented, signed, and acknowledged. Each entry captures who did it (name, email, national ID code when supplied, and the IP address the action came from) and a precise timestamp. If a signature is ever questioned, you have the record.

Long-term retention

Keep executed documents for as long as your business and your regulators require, stored encrypted for up to 5 years. Your signed agreements stay available and verifiable for the entire lifetime of the contract, not just the day it was signed.

Bring your own storage

Point the service at your own storage, so signed documents live inside your own infrastructure. Your data stays under your control, and your users get the same signing flow either way.

Automated cleanup

Set a retention period and let documents delete themselves when it expires. Meet data-minimisation and right-to-erasure obligations without a manual cleanup job or a scheduled script to maintain.

Web Forms

Let your users fill in a form, generate the document from their answers, and drop them straight into the signing flow. Enable the Sign the document action on the form, and on submit the user is redirected into the review-and-sign experience automatically.

Talk to us before you build

Meet Michal Líška, our pre-sales engineer. He knows the service inside out and can answer any questions about embedding the signing and review flow into your application.

Book a demo call with Michal ›

Frequently asked questions

How is this different from an e-signature API?
Most e-signature APIs sign a document you already have. PDF Generator API also generates the document from your templates and JSON data, so you go from structured data to a signed, audited PDF in one platform. If you already have a finished PDF, you can sign that too.

Can I sign a PDF I already have?
Yes. Send an existing PDF to storage with a public HTTPS file_url or a base64-encoded file_base64, set output to viewer, and you get back a review URL. You do not have to use our templates.

How do I authenticate?
Requests use a JSON Web Token (JWT) as a Bearer token, signed server-side with your API key and secret. The base URL for all endpoints is https://us1.pdfgeneratorapi.com/api/v4.

Can I see who signed and when?
Yes. GET /documents/{publicId}/actions returns every action, from opened and reviewed to signed, with the signer’s identity, IP address, and timestamp. GET /documents/{publicId}/versions returns the full version history.

Where are signed documents stored?
In our encrypted storage by default, with configurable long-term retention. You can also bring your own storage (e.g. AWS S3, Azure, Dropbox, Google Drive) so documents live in your infrastructure.