Add annotations to PDFs with Nutrient Document Web Services API on Zapier

This tutorial shows you how to automatically annotate PDF files using the Nutrient Document Web Services API on Zapier. You’ll trigger the workflow when a new PDF is uploaded to a Google Drive folder, find a matching JSON file containing annotation data, and apply the annotations using Nutrient.

Illustration: Add annotations to PDFs with Nutrient Document Web Services API on Zapier

What is Zapier?

Zapier is an automation platform that connects your favorite apps and services with no code required. You can build “Zaps” to automate repetitive tasks by setting up triggers and actions between apps like Google Drive, Slack, Gmail, and more.

In this tutorial, you’ll learn how to use Zapier to automatically annotate PDF files using the Nutrient API.

What is the Nutrient API?

Nutrient Document Web Services API is a powerful platform for document automation. With your free account, you get 100 credits, which you can use to perform various document operations. Each tool (e.g. conversion, signing, flattening) consumes a different amount of credits depending on complexity.

Nutrient offers more than 30 tools with the ability to:

Convert images and documents to PDF
Merge, split, or reorder pages
Add digital signatures, watermarks, or annotations
Run OCR, redact, flatten, and more

All you need is an API key from a free account to get started. You can chain these tools together in Zapier to build powerful, automated PDF workflows.

What you’ll need

A Zapier account (a pro plan is necessary for multi-step Zaps)
A Google Drive account
A PDF file uploaded to a Google Drive folder
A JSON file with annotation instructions uploaded to a Google Drive folder (publicly shareable or findable)
A Nutrient Document Web Services API key — sign up here

Step 1 — Trigger a new file in a Google Drive folder

Select Google Drive as the trigger app.

Select Google Drive as the trigger app in Zapier

Choose the New File in Folder trigger event.

Choose ‘New File in Folder’ as the trigger event

Connect your Google Drive account.
Configure the trigger:

In the Drive field, select your Google Drive.

Select which Drive to monitor for new PDF files

In the Folder field, select or create a folder (e.g. nutrient).

Choose or create the folder to watch for new PDFs

Ensure that the option for Include Deleted Files? is set to Only return non-deleted files.

Once configured, test the trigger by selecting a sample PDF file from the folder to confirm it’s being pulled into the Zap correctly.

Test the trigger by pulling in a sample PDF file

Step 2 — Find a matching JSON annotation file

Add a new step by going to Google Drive > Find a File.

Add a new ‘Find File’ action step in Google Drive

In the configuration, select the following:

Filename — Type the expected name of your annotation JSON file (e.g. annotations.json).
Search Type — Set to Filename contains.
Drive — Select My Drive.

Enter the expected filename and search configuration for the JSON file

Make sure your JSON file sharing access is set to Anyone with the link in Google Drive so that Zapier can access it.

The output should include a web content link or direct file URL — you’ll use this in the next step to apply annotations.

Test the step to verify that the correct JSON file was found

Step 3 — Add annotations to PDF action (Nutrient API)

Next, select Nutrient Document Web Services API as the app.

Select Nutrient API as the action app in Zapier

Choose the Add Annotations to PDF action.

Choose ‘Add Annotations to PDF’ as the action event

Connect your Nutrient API account with your API key.

Paste your Nutrient API key to connect your account

You can find your API key in the Nutrient dashboard.

Locate and copy your API key from the Nutrient dashboard

Fill out the action fields:
- PDF File URL — From step 1 (the PDF trigger).

Map the PDF file URL to the action configuration

Annotations JSON URL — From step 2 (the find file step).

Map the Annotations JSON file URL to the action configuration

Output File Name — Optional (e.g. annotated_file.pdf).

The file must be accessible via a public URL or direct download link (Zapier will handle this if sourced from Google Drive).

Test the step to verify that the annotations are successfully applied. You can use our sample document (annotations.pdf) and sample Instant JSON file (annotations.json) for testing this step.

Run a test to verify that annotations are successfully applied to the PDF

Step 4 — Upload the annotated PDF to Google Drive

Now, add another step by selecting Google Drive as the app and Upload File as the action event. Connect your Google Drive account if needed.

Choose ‘Upload File’ as the final action to save the annotated PDF

Select your drive and the folder where the updated PDF should be saved. In the File field, use the output from the Nutrient API step. Optionally, set a custom file name or extension to keep things consistent and organized.

Map the output of the annotation step to upload it to Google Drive

Zapier may warn you about a potential Zap loop if you use the same folder for the input and the output. You can avoid this by uploading the updated file to a different folder.

Test the entire Zap to ensure the PDF is annotated correctly and the final file appears in the target folder. Once everything is working, click Publish to automate the workflow.

Final test step to confirm the annotated PDF was uploaded

Conclusion

With this Zap, you’ve automated the process of applying annotations to PDFs using a structured JSON file and the Nutrient API. This is ideal for review workflows, programmatic markup, or scaling document collaboration without manual work. You can build on this flow by chaining it with other tools like redaction, signing, or form filling.

Author

Hulya Masharipov Technical Writer

Hulya is a frontend web developer and technical writer at Nutrient who enjoys creating responsive, scalable, and maintainable web experiences. She’s passionate about open source, web accessibility, cybersecurity privacy, and blockchain.

Explore related topics

Zapier Nutrient API PDF Annotations Google Drive Automation