DocGen API
Turn data into signed-ready documents
Upload a .docx template with tags, send a JSON payload, and get a PDF back — ready to send for signature, ready to download, ready to ship. Start building with our document generation API for free.
Document generation for people who shipBuild signing that feels like part of your product
Why DocGen replaces the tangle of PDF libraries, Word templates, and brittle merge scripts you're already running.
docx in, populated PDF out
Start from a Word document and add tags where your data goes. Our document template API merges your JSON payload and returns a populated PDF — no extra steps.
From raw data to polished documents
Pass your data and our PDF generation API renders it into polished, professional documents. Tables, lists, and repeating sections build themselves.
Conditional content, per recipient
Show, hide, or adapt content based on your data. The document automation API applies your rules so every document reflects the right details for each recipient.
Signature-ready, by default
DocGen output drops straight into any SignNow signing flow with no re-upload, no format conversion. Generate, send, sign. One pipeline, one audit trail.
Works with your stack
Add eSignature workflows to 270+ apps. REST APIs, OAuth, webhooks, and iframe embeds are built in so you integrate faster without custom infrastructure or niche SDKs.
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Why choose SignNow eSignature API?
Legal compliance
SignNow’s electronic signature API is built to meet the highest legal and security standards, including eIDAS, ESIGN, QES, HIPAA, FDA Part 11, SOC 2, AES encryption, and more.
Learn more about security
Qualified eSignature
Qualified electronic signature provides the highest level of identity verification and carries the same legal weight as a handwritten signature.
Get more, for less
Up to 2.4x cheaper than the leading eSign API provider. Based on a feature by feature comparison, SignNow provides the same extensive feature set as the leading provider at a much lower cost.
Data security
SignNow’s eSignature API ensures data security with 256-bit encryption, detailed audit trails, disaster recovery protocols, and two-factor authentication for robust protection and compliance.
Support you can depend on
SignNow processes over 3.54M documents annually, providing SMBs with an eSignature solution they can count on for important documents as well as live, technical support from in-house experts.
Customizability & branding
Fully customize the end-to-end signer experience—from document preparation and notification emails to the signing process—with custom redirects to seamlessly integrate with your user workflow.
Build with the DocGen API. Ship faster
Our user reviews speak for themselves
We built everything off the API documentation that SignNow provides and some back and forth with support. It's taken us about two months to achieve this level of implementation with SignNow, and the system has been very reliable.
I integrated SignNow, and after working with their customer success team, I knew I made the right decision. I like the direction the company is going in and the way they show up for us, so I'm stoked to continue working with SignNow.
Frequently asked questions
Common DocGen questions from builders.
What file format does DocGen accept?
Templates are .docx files with inline tags — text placeholders that SignNow substitutes at generation time. Uploads can be up to 10 MB. Generated documents are delivered as PDF, making DocGen ideal for teams using a generate PDF from template API solution or building with a PDF template API.
How do tags work?
You add named tags to your .docx template where data should land. When you generate, pass a JSON payload whose keys match your tag names and the auto fill PDF API substitutes the values. Arrays of objects expand into repeating rows for tables and lists.
Can I generate from DocGen and send straight to signing?
Yes. The rendered document flows directly into any SignNow signing path, whether embedded, email, or API-driven. There's no intermediate upload or format step. You get one continuous audit trail from generation to signature.
Is generation synchronous?
Generation is asynchronous. The generate endpoint returns a process_id with status in_progress immediately. Poll GET /v2/document-generations/{process_id}/status until status is completed. Then the document is ready to send, download, or route into signing.
Ready to get started?
Easily send documents for signature, request payments, create reusable templates with fillable fields, and track the status of documents in real-time with SignNow API.
