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PDF Annotations API

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

Built for seamless integration

Use a simple API to sign and validate documents in your own platform or automate it with tools like Zapier, without dealing with complex signature logic or infrastructure.

Try it instantly on Zapier

No code? No problem. Connect Nutrient DWS Processor API to your favorite apps with Zapier to automate document workflows and save time on repetitive tasks.

Simple and transparent pricing

Select a package that suits your needs according to the number of credits you wish to spend. Each API tool and action has a specific credit cost.

Nutrient is used by

Try it out

This example will import Instant JSON with annotations to PDF.

1

Use Your Free API Calls

Sign up and receive 100 credits for free, or log in to automatically add your API key to sample code. If you are not sure how credits are consumed read more in our pricing documentation , or check out this guide on calculating credit usage.

Add a File

Add a PDF named annotations.pdf and JSON named annotations.json to your project folder. You can use our sample document and sample Instant JSON. The file name is case sensitive. Make sure the file name matches the file name in the sample code.

Run the Code

Copy the code and run it from the same folder you added the files to. For more information, see our language-specific getting started guides.

View the Results

Open result.pdf in your project folder to view the results.

curl -X POST https://api.nutrient.io/build \
  -H "Authorization: Bearer your_api_key_here" \
  -o result.pdf \
  --fail \
  -F [email protected] \
  -F [email protected] \
  -F instructions='{
      "parts": [
        {
          "file": "document"
        }
      ],
      "actions": [
        {
          "type": "applyInstantJson",
          "file": "annotations.json"
        }
      ]
    }'
curl -X POST https://api.nutrient.io/build ^
  -H "Authorization: Bearer your_api_key_here" ^
  -o result.pdf ^
  --fail ^
  -F [email protected] ^
  -F [email protected] ^
  -F instructions="{\"parts\": [{\"file\": \"document\"}], \"actions\": [{\"type\": \"applyInstantJson\", \"file\": \"annotations.json\"}]}"
package com.example.pspdfkit;

import java.io.File;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;

import org.json.JSONArray;
import org.json.JSONObject;

import okhttp3.MediaType;
import okhttp3.MultipartBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public final class PspdfkitApiExample {
  public static void main(final String[] args) throws IOException {
    final RequestBody body = new MultipartBody.Builder()
      .setType(MultipartBody.FORM)
      .addFormDataPart(
        "document",
        "annotations.pdf",
        RequestBody.create(
          MediaType.parse("application/pdf"),
          new File("annotations.pdf")
        )
      )
      .addFormDataPart(
        "annotations.json",
        "annotations.json",
        RequestBody.create(
          MediaType.parse("application/octet-stream"),
          new File("annotations.json")
        )
      )
      .addFormDataPart(
        "instructions",
        new JSONObject()
          .put("parts", new JSONArray()
            .put(new JSONObject()
              .put("file", "document")
            )
          )
          .put("actions", new JSONArray()
            .put(new JSONObject()
              .put("type", "applyInstantJson")
              .put("file", "annotations.json")
            )
          ).toString()
      )
      .build();

    final Request request = new Request.Builder()
      .url("https://api.nutrient.io/build")
      .method("POST", body)
      .addHeader("Authorization", "Bearer your_api_key_here")
      .build();

    final OkHttpClient client = new OkHttpClient()
      .newBuilder()
      .build();

    final Response response = client.newCall(request).execute();

    if (response.isSuccessful()) {
      Files.copy(
        response.body().byteStream(),
        FileSystems.getDefault().getPath("result.pdf"),
        StandardCopyOption.REPLACE_EXISTING
      );
    } else {
      // Handle the error
      throw new IOException(response.body().string());
    }
  }
}
using System;
using System.IO;
using System.Net;
using RestSharp;

namespace PspdfkitApiDemo
{
  class Program
  {
    static void Main(string[] args)
    {
      var client = new RestClient("https://api.nutrient.io/build");

      var request = new RestRequest(Method.POST)
        .AddHeader("Authorization", "Bearer your_api_key_here")
        .AddFile("document", "annotations.pdf")
        .AddFile("annotations.json", "annotations.json")
        .AddParameter("instructions", new JsonObject
        {
          ["parts"] = new JsonArray
          {
            new JsonObject
            {
              ["file"] = "document"
            }
          },
          ["actions"] = new JsonArray
          {
            new JsonObject
            {
              ["type"] = "applyInstantJson",
              ["file"] = "annotations.json"
            }
          }
        }.ToString());

      request.AdvancedResponseWriter = (responseStream, response) =>
      {
        if (response.StatusCode == HttpStatusCode.OK)
        {
          using (responseStream)
          {
            using var outputFileWriter = File.OpenWrite("result.pdf");
            responseStream.CopyTo(outputFileWriter);
          }
        }
        else
        {
          var responseStreamReader = new StreamReader(responseStream);
          Console.Write(responseStreamReader.ReadToEnd());
        }
      };

      client.Execute(request);
    }
  }
}
// This code requires Node.js. Do not run this code directly in a web browser.

const axios = require('axios')
const FormData = require('form-data')
const fs = require('fs')

const formData = new FormData()
formData.append('instructions', JSON.stringify({
  parts: [
    {
      file: "document"
    }
  ],
  actions: [
    {
      type: "applyInstantJson",
      file: "annotations.json"
    }
  ]
}))
formData.append('document', fs.createReadStream('annotations.pdf'))
formData.append('annotations.json', fs.createReadStream('annotations.json'))

;(async () => {
  try {
    const response = await axios.post('https://api.nutrient.io/build', formData, {
      headers: formData.getHeaders({
        'Authorization': 'Bearer your_api_key_here'
      }),
      responseType: "stream"
    })

    response.data.pipe(fs.createWriteStream("result.pdf"))
  } catch (e) {
    const errorString = await streamToString(e.response.data)
    console.log(errorString)
  }
})()

function streamToString(stream) {
  const chunks = []
  return new Promise((resolve, reject) => {
    stream.on("data", (chunk) => chunks.push(Buffer.from(chunk)))
    stream.on("error", (err) => reject(err))
    stream.on("end", () => resolve(Buffer.concat(chunks).toString("utf8")))
  })
}
import requests
import json

response = requests.request(
  'POST',
  'https://api.nutrient.io/build',
  headers = {
    'Authorization': 'Bearer your_api_key_here'
  },
  files = {
    'document': open('annotations.pdf', 'rb'),
    'annotations.json': open('annotations.json', 'rb')
  },
  data = {
    'instructions': json.dumps({
      'parts': [
        {
          'file': 'document'
        }
      ],
      'actions': [
        {
          'type': 'applyInstantJson',
          'file': 'annotations.json'
        }
      ]
    })
  },
  stream = True
)

if response.ok:
  with open('result.pdf', 'wb') as fd:
    for chunk in response.iter_content(chunk_size=8096):
      fd.write(chunk)
else:
  print(response.text)
  exit()
<?php

$FileHandle = fopen('result.pdf', 'w+');

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.nutrient.io/build',
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_POSTFIELDS => array(
    'instructions' => '{
      "parts": [
        {
          "file": "document"
        }
      ],
      "actions": [
        {
          "type": "applyInstantJson",
          "file": "annotations.json"
        }
      ]
    }',
    'document' => new CURLFILE('annotations.pdf'),
    'annotations.json' => new CURLFILE('annotations.json')
  ),
  CURLOPT_HTTPHEADER => array(
    'Authorization: Bearer your_api_key_here'
  ),
  CURLOPT_FILE => $FileHandle,
));

$response = curl_exec($curl);

curl_close($curl);

fclose($FileHandle);

POST https://api.nutrient.io/build HTTP/1.1
Content-Type: multipart/form-data; boundary=--customboundary
Authorization: Bearer your_api_key_here

--customboundary
Content-Disposition: form-data; name="instructions"
Content-Type: application/json

{
  "parts": [
    {
      "file": "document"
    }
  ],
  "actions": [
    {
      "type": "applyInstantJson",
      "file": "annotations.json"
    }
  ]
}
--customboundary
Content-Disposition: form-data; name="document"; filename="annotations.pdf"
Content-Type: application/pdf

(document data)
--customboundary
Content-Disposition: form-data; name="annotations.json"; filename="annotations.json"
Content-Type: application/octet-stream

(annotations.json data)
--customboundary--
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Your API Key

Instant JSON

We created Instant JSON to bring annotations, forms, and bookmarks into a modern format while keeping all important properties to make the Instant JSON spec work with PDF documents. The format is fully documented and can easily be converted to XFDF to make it interoperable.

Please refer to the Instant JSON Reference for full reference documentation of the 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.

Ready to try it?

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