Getting Started with Other Languages

PSPDFKit API is offered as a simple HTTP-based API. That means it can be used from any programming language capable of POSTing multipart/form-data payloads. Here, we'll outline the general steps that apply, regardless of the language you choose.

To make use of PSPDFKit API, you essentially have to perform the following steps:

  1. 1
    Create your instructions object. Refer to the API reference for more information on how instructions needs to look. You can also look at any of our tools pages to see how to use a specific function.
  2. 2
    Encode the instructions object as a JSON object, if you didn't already.
  3. 3
    Next, assemble your multipart/form-data payload. Here, you need to include both the instructions object with the name instructions, and any assets with the name you use to refer to them, in the instructions object.
  4. 4
    Finally, POST your multipart payload to https://api.pspdfkit.com/build, making sure to include your API key in the authorization header.

To help you picture this more clearly, here are code samples for flattening a PDF in multiple languages. They all follow the general approach for using PSPDFKit API:

curl -X POST https://api.pspdfkit.com/build \
  -H "Authorization: Bearer your_api_key_here" \
  -o result.pdf \
  --fail \
  -F document.pdf=@document.pdf \
  -F instructions='{
      "parts": [
        {
          "file": "document.pdf"
        }
      ],
      "actions": [
        {
          "type": "flatten"
        }
      ]
    }'
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.pdf",
        "document.pdf",
        RequestBody.create(
          new File("document.pdf"),
          MediaType.parse("application/pdf")
        )
      )
      .addFormDataPart(
        "instructions",
        new JSONObject()
          .put("parts", new JSONArray()
            .put(new JSONObject()
              .put("file", "document.pdf")
            )
          )
          .put("actions", new JSONArray()
            .put(new JSONObject()
              .put("type", "flatten")
            )
          ).toString()
      )
      .build();

    final Request request = new Request.Builder()
      .url("https://api.pspdfkit.com/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.pspdfkit.com/build");

      var request = new RestRequest(Method.POST)
        .AddHeader("Authorization", "Bearer your_api_key_here")
        .AddFile("document.pdf", "document.pdf")
        .AddParameter("instructions", new JsonObject
        {
          ["parts"] = new JsonArray
          {
            new JsonObject
            {
              ["file"] = "document.pdf"
            }
          },
          ["actions"] = new JsonArray
          {
            new JsonObject
            {
              ["type"] = "flatten"
            }
          }
        }.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);
    }
  }
}
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.pdf"
    }
  ],
  actions: [
    {
      type: "flatten"
    }
  ]
}))
formData.append('document.pdf', fs.createReadStream('document.pdf'))

;(async () => {
  try {
    const response = await axios.post('https://api.pspdfkit.com/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

instructions = {
  'parts': [
    {
      'file': 'document.pdf'
    }
  ],
  'actions': [
    {
      'type': 'flatten'
    }
  ]
}

response = requests.request(
  'POST',
  'https://api.pspdfkit.com/build',
  headers = {
    'Authorization': 'Bearer your_api_key_here'
  },
  files = {
    'document.pdf': open('document.pdf', 'rb')
  },
  data = {
    'instructions': json.dumps(instructions)
  },
  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();

$instructions = '{
  "parts": [
    {
      "file": "document.pdf"
    }
  ],
  "actions": [
    {
      "type": "flatten"
    }
  ]
}';

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.pspdfkit.com/build',
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_POSTFIELDS => array(
    'instructions' => $instructions,
    'document.pdf' => new CURLFILE('document.pdf')
  ),
  CURLOPT_HTTPHEADER => array(
    'Authorization: Bearer your_api_key_here'
  ),
  CURLOPT_FILE => $FileHandle,
));

$response = curl_exec($curl);

curl_close($curl);

fclose($FileHandle);