PDF annotations API

Programmatically import annotations into your PDF documents with our Instant JSON import API.

Flexible, JSON-driven markup

Add highlights, sticky notes, text boxes, shapes, and more with precise control over position, color, and page placement using a simple JSON format.

Automate with Zapier

Automatically add annotations to PDF files in Google Drive using our Zapier integration. Just supply your annotation instructions in JSON, and the Nutrient API takes care of the rest.

No manual editing needed

Automate the annotation process across entire document workflows. Perfect for feedback loops, quality control, or digital signing preparation.

Used by Lufthansa, Disney, Autodesk, UBS, Dropbox, IBM
Lufthansa
Disney
Autodesk
UBS
Dropbox
IBM

Try it out

This example will import Instant JSON with annotations to PDF.


Try it out in three steps

  1. Add annotations.pdf and annotations.json to your project folder.
  2. Run the code from the same folder.
  3. Open result.pdf to see the output.
curl -X POST https://api.nutrient.io/build \
-H "Authorization: Bearer your_api_key_here" \
-o result.pdf \
--fail \
-F document=@document.pdf \
-F annotations.json=@annotations.json \
-F instructions='{
"parts": [
{
"file": "document"
}
],
"actions": [
{
"type": "applyInstantJson",
"file": "annotations.json"
}
]
}'

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Instant JSON

The Instant JSON format is the native annotation format of the Nutrient API, and it defines an extensive number of annotation types and properties for your documents. Use this format to programmatically generate robust, feature-rich annotations for your documents.

Instant JSON annotation format

Security is our top priority

No document storage

No input or resulting documents are stored on our infrastructure. All files are deleted as soon as a request finishes. Alternatively, check out our self-hosted product.

HTTPS encryption

All communication between your application and Nutrient is done via HTTPS to ensure your data is encrypted when it’s sent to us.

Safe payment processing

All payments are handled by Paddle. Nutrient DWS Processor API never has direct access to any of your payment data.

Frequently asked questions

What is a PDF annotations API?

A PDF annotations API lets you add and manage markup — highlights, comments, sticky notes, text boxes, shapes, and more — in PDF documents programmatically over REST. Nutrient DWS Processor API uses the Instant JSON format to apply annotations without manual editing, so you can automate annotation across entire document workflows.

What annotation types are supported?

The API supports a wide range of annotation types through the Instant JSON format, including highlights, sticky notes, comments, text boxes, shapes, and ink markup, with control over position, color, and page placement. See the Instant JSON reference for the full list of types and properties.

Can I add annotations programmatically in PHP?

Yes. The API is REST-based, so it works from PHP as well as JavaScript, Python, Java, and HTTP (curl). Ready-to-use examples and a Postman collection help you send your first annotation request quickly from any of these languages.

How do I import annotations into a PDF?

Send your document along with Instant JSON annotation instructions to the Processor API, and it applies the annotations and returns the updated PDF. The getting started guide covers API key setup, and the Instant JSON reference documents the import format.

Is there a free tier, and how does pricing work?

You can start free with Nutrient DWS credits — no credit card required — and test before scaling. See the Processor API pricing page for current credit details.

Ready to try it?

Create an account to get your DWS Processor API key and start making API calls.