1 credit

Merge PDF Node.js API

Merge multiple files into one document with our Node.js PDF merging API.

Why Nutrient DWS API?

SOC 2 Compliant

Build the workflows you need without worrying about security. We don’t store any document data, and our API endpoints are served through encrypted connections.

Easy Integration

Get up and running in hours, not weeks. Access well-documented APIs and code samples that make integrating with your existing workflows a snap.

Robust and Flexible

With access to more than 30 tools, you can process one document in multiple ways by using API credits. Generate PDF from HTML, convert Word, Excel, PowerPoint and image files to PDF, and more.

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.

Try It Out

This example will merge the two supplied documents into one PDF. The order of the documents in the final PDF is controlled by the order of the parts array.

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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 two PDFs named first_half.pdf and second_half.pdf to your project folder. You can also use our sample files: first_half.pdf and second_half.pdf. 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 first_half=@first_half.pdf \
  -F second_half=@second_half.pdf \
  -F instructions='{
      "parts": [
        {
          "file": "first_half"
        },
        {
          "file": "second_half"
        }
      ]
    }'
curl -X POST https://api.nutrient.io/build ^
  -H "Authorization: Bearer your_api_key_here" ^
  -o result.pdf ^
  --fail ^
  -F first_half=@first_half.pdf ^
  -F second_half=@second_half.pdf ^
  -F instructions="{\"parts\": [{\"file\": \"first_half\"}, {\"file\": \"second_half\"}]}"
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(
        "first_half",
        "first_half.pdf",
        RequestBody.create(
          MediaType.parse("application/pdf"),
          new File("first_half.pdf")
        )
      )
      .addFormDataPart(
        "second_half",
        "second_half.pdf",
        RequestBody.create(
          MediaType.parse("application/pdf"),
          new File("second_half.pdf")
        )
      )
      .addFormDataPart(
        "instructions",
        new JSONObject()
          .put("parts", new JSONArray()
            .put(new JSONObject()
              .put("file", "first_half")
            )
            .put(new JSONObject()
              .put("file", "second_half")
            )
          ).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("first_half", "first_half.pdf")
        .AddFile("second_half", "second_half.pdf")
        .AddParameter("instructions", new JsonObject
        {
          ["parts"] = new JsonArray
          {
            new JsonObject
            {
              ["file"] = "first_half"
            },
            new JsonObject
            {
              ["file"] = "second_half"
            }
          }
        }.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: "first_half"
    },
    {
      file: "second_half"
    }
  ]
}))
formData.append('first_half', fs.createReadStream('first_half.pdf'))
formData.append('second_half', fs.createReadStream('second_half.pdf'))

;(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 = {
    'first_half': open('first_half.pdf', 'rb'),
    'second_half': open('second_half.pdf', 'rb')
  },
  data = {
    'instructions': json.dumps({
      'parts': [
        {
          'file': 'first_half'
        },
        {
          'file': 'second_half'
        }
      ]
    })
  },
  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": "first_half"
        },
        {
          "file": "second_half"
        }
      ]
    }',
    'first_half' => new CURLFILE('first_half.pdf'),
    'second_half' => new CURLFILE('second_half.pdf')
  ),
  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": "first_half"
    },
    {
      "file": "second_half"
    }
  ]
}
--customboundary
Content-Disposition: form-data; name="first_half"; filename="first_half.pdf"
Content-Type: application/pdf

(first_half data)
--customboundary
Content-Disposition: form-data; name="second_half"; filename="second_half.pdf"
Content-Type: application/pdf

(second_half data)
--customboundary--
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