Run this command to install the SDK:

npm install cloudmersive-convert-api-client --save


Or add this snippet to your package.json:

  "dependencies": {
    "cloudmersive-convert-api-client": "^2.6.3"
  }


var CloudmersiveConvertApiClient = require('cloudmersive-convert-api-client');
var defaultClient = CloudmersiveConvertApiClient.ApiClient.instance;

// Configure API key authorization: Apikey
var Apikey = defaultClient.authentications['Apikey'];
Apikey.apiKey = 'YOUR API KEY';



var apiInstance = new CloudmersiveConvertApiClient.EditPdfApi();

var watermarkText = "watermarkText_example"; // String | Watermark text to add to the PDF (required)

var inputFile = Buffer.from(fs.readFileSync("C:\\temp\\inputfile").buffer); // File | Input file to perform the operation on.

var opts = { 
  'fontName': "fontName_example", // String | Font Family Name for the watermark text; default is Times New Roman
  'fontSize': 8.14, // Number | Font Size in points of the text; default is 150
  'fontColor': "fontColor_example", // String | Font color in hexadecimal or HTML color name; default is Red
  'fontTransparency': 8.14 // Number | Font transparency between 0.0 (completely transparent) to 1.0 (fully opaque); default is 0.5
};

var callback = function(error, data, response) {
  if (error) {
    console.error(error);
  } else {
    console.log('API called successfully. Returned data: ' + data);
  }
};
apiInstance.editPdfWatermarkText(watermarkText, inputFile, opts, callback);

Run this command to install the SDK:

pip install cloudmersive-convert-api-client


from __future__ import print_function
import time
import cloudmersive_convert_api_client
from cloudmersive_convert_api_client.rest import ApiException
from pprint import pprint

# Configure API key authorization: Apikey
configuration = cloudmersive_convert_api_client.Configuration()
configuration.api_key['Apikey'] = 'YOUR_API_KEY'



# create an instance of the API class
api_instance = cloudmersive_convert_api_client.EditPdfApi(cloudmersive_convert_api_client.ApiClient(configuration))
watermark_text = 'watermark_text_example' # str | Watermark text to add to the PDF (required)
input_file = '/path/to/file' # file | Input file to perform the operation on.
font_name = 'font_name_example' # str | Font Family Name for the watermark text; default is Times New Roman (optional)
font_size = 8.14 # float | Font Size in points of the text; default is 150 (optional)
font_color = 'font_color_example' # str | Font color in hexadecimal or HTML color name; default is Red (optional)
font_transparency = 8.14 # float | Font transparency between 0.0 (completely transparent) to 1.0 (fully opaque); default is 0.5 (optional)

try:
    # Add a text watermark to a PDF
    api_response = api_instance.edit_pdf_watermark_text(watermark_text, input_file, font_name=font_name, font_size=font_size, font_color=font_color, font_transparency=font_transparency)
    pprint(api_response)
except ApiException as e:
    print("Exception when calling EditPdfApi->edit_pdf_watermark_text: %s\n" % e)

Run this command to install the SDK:

Install-Package Cloudmersive.APIClient.NET.DocumentAndDataConvert -Version 3.4.2


using System;
using System.Diagnostics;
using Cloudmersive.APIClient.NET.DocumentAndDataConvert.Api;
using Cloudmersive.APIClient.NET.DocumentAndDataConvert.Client;
using Cloudmersive.APIClient.NET.DocumentAndDataConvert.Model;

namespace Example
{
    public class EditPdfWatermarkTextExample
    {
        public void main()
        {
            // Configure API key authorization: Apikey
            Configuration.Default.AddApiKey("Apikey", "YOUR_API_KEY");
            
            

            var apiInstance = new EditPdfApi();
            var watermarkText = watermarkText_example;  // string | Watermark text to add to the PDF (required)
            var inputFile = new System.IO.FileStream("C:\\temp\\inputfile", System.IO.FileMode.Open); // System.IO.Stream | Input file to perform the operation on.
            var fontName = fontName_example;  // string | Font Family Name for the watermark text; default is Times New Roman (optional) 
            var fontSize = 8.14;  // decimal? | Font Size in points of the text; default is 150 (optional) 
            var fontColor = fontColor_example;  // string | Font color in hexadecimal or HTML color name; default is Red (optional) 
            var fontTransparency = 8.14;  // decimal? | Font transparency between 0.0 (completely transparent) to 1.0 (fully opaque); default is 0.5 (optional) 

            try
            {
                // Add a text watermark to a PDF
                byte[] result = apiInstance.EditPdfWatermarkText(watermarkText, inputFile, fontName, fontSize, fontColor, fontTransparency);
                Debug.WriteLine(result);
            }
            catch (Exception e)
            {
                Debug.Print("Exception when calling EditPdfApi.EditPdfWatermarkText: " + e.Message );
            }
        }
    }
}

To install with Maven, add a reference to the repository in pom.xml:

<repositories>
    <repository>
        <id>jitpack.io</id>
        <url>https://jitpack.io</url>
    </repository>
</repositories>


And add a reference to the dependency in pom.xml:

<dependencies>
<dependency>
    <groupId>com.github.Cloudmersive</groupId>
    <artifactId>Cloudmersive.APIClient.Java</artifactId>
    <version>v4.25</version>
</dependency>
</dependencies>


To install with Gradle, add it in your root build.gradle at the end of repositories:

allprojects {
	repositories {
		...
		maven { url 'https://jitpack.io' }
	}
}


And add the dependency in build.gradle:

dependencies {
        implementation 'com.github.Cloudmersive:Cloudmersive.APIClient.Java:v4.25'
}


// Import classes:
//import com.cloudmersive.client.invoker.ApiClient;
//import com.cloudmersive.client.invoker.ApiException;
//import com.cloudmersive.client.invoker.Configuration;
//import com.cloudmersive.client.invoker.auth.*;
//import com.cloudmersive.client.EditPdfApi;

ApiClient defaultClient = Configuration.getDefaultApiClient();

// Configure API key authorization: Apikey
ApiKeyAuth Apikey = (ApiKeyAuth) defaultClient.getAuthentication("Apikey");
Apikey.setApiKey("YOUR API KEY");
// Uncomment the following line to set a prefix for the API key, e.g. "Token" (defaults to null)
//Apikey.setApiKeyPrefix("Token");

EditPdfApi apiInstance = new EditPdfApi();
String watermarkText = "watermarkText_example"; // String | Watermark text to add to the PDF (required)
File inputFile = new File("/path/to/file"); // File | Input file to perform the operation on.
String fontName = "fontName_example"; // String | Font Family Name for the watermark text; default is Times New Roman
BigDecimal fontSize = new BigDecimal(); // BigDecimal | Font Size in points of the text; default is 150
String fontColor = "fontColor_example"; // String | Font color in hexadecimal or HTML color name; default is Red
BigDecimal fontTransparency = new BigDecimal(); // BigDecimal | Font transparency between 0.0 (completely transparent) to 1.0 (fully opaque); default is 0.5
try {
    byte[] result = apiInstance.editPdfWatermarkText(watermarkText, inputFile, fontName, fontSize, fontColor, fontTransparency);
    System.out.println(result);
} catch (ApiException e) {
    System.err.println("Exception when calling EditPdfApi#editPdfWatermarkText");
    e.printStackTrace();
}

Run this command to install the SDK:

composer require cloudmersive/cloudmersive_document_convert_api_client


<?php
require_once(__DIR__ . '/vendor/autoload.php');

// Configure API key authorization: Apikey
$config = Swagger\Client\Configuration::getDefaultConfiguration()->setApiKey('Apikey', 'YOUR_API_KEY');



$apiInstance = new Swagger\Client\Api\EditPdfApi(
    
    
    new GuzzleHttp\Client(),
    $config
);
$watermark_text = "watermark_text_example"; // string | Watermark text to add to the PDF (required)
$input_file = "/path/to/file"; // \SplFileObject | Input file to perform the operation on.
$font_name = "font_name_example"; // string | Font Family Name for the watermark text; default is Times New Roman
$font_size = 8.14; // float | Font Size in points of the text; default is 150
$font_color = "font_color_example"; // string | Font color in hexadecimal or HTML color name; default is Red
$font_transparency = 8.14; // float | Font transparency between 0.0 (completely transparent) to 1.0 (fully opaque); default is 0.5

try {
    $result = $apiInstance->editPdfWatermarkText($watermark_text, $input_file, $font_name, $font_size, $font_color, $font_transparency);
    print_r($result);
} catch (Exception $e) {
    echo 'Exception when calling EditPdfApi->editPdfWatermarkText: ', $e->getMessage(), PHP_EOL;
}
?>

Add the Objective-C client to your Podfile:

pod 'CloudmersiveDocumentAndDataConvertApiClient', '~> 1.0'


CMDefaultConfiguration *apiConfig = [CMDefaultConfiguration sharedConfig];

// Configure API key authorization: (authentication scheme: Apikey)
[apiConfig setApiKey:@"YOUR_API_KEY" forApiKeyIdentifier:@"Apikey"];




NSString* watermarkText = @"watermarkText_example"; // Watermark text to add to the PDF (required)
NSURL* inputFile = [NSURL fileURLWithPath:@"/path/to/file"]; // Input file to perform the operation on.
NSString* fontName = @"fontName_example"; // Font Family Name for the watermark text; default is Times New Roman (optional)
NSNumber* fontSize = @8.14; // Font Size in points of the text; default is 150 (optional)
NSString* fontColor = @"fontColor_example"; // Font color in hexadecimal or HTML color name; default is Red (optional)
NSNumber* fontTransparency = @8.14; // Font transparency between 0.0 (completely transparent) to 1.0 (fully opaque); default is 0.5 (optional)

CMEditPdfApi*apiInstance = [[CMEditPdfApi alloc] init];

// Add a text watermark to a PDF
[apiInstance editPdfWatermarkTextWithWatermarkText:watermarkText
              inputFile:inputFile
              fontName:fontName
              fontSize:fontSize
              fontColor:fontColor
              fontTransparency:fontTransparency
          completionHandler: ^(NSData* output, NSError* error) {
                        if (output) {
                            NSLog(@"%@", output);
                        }
                        if (error) {
                            NSLog(@"Error calling CMEditPdfApi->editPdfWatermarkText: %@", error);
                        }
                    }];

Add the Ruby client to your Gemfile:

gem 'cloudmersive-convert-api-client', '~> 2.1.6'


# load the gem
require 'cloudmersive-convert-api-client'
# setup authorization
CloudmersiveConvertApiClient.configure do |config|
  # Configure API key authorization: Apikey
  config.api_key['Apikey'] = 'YOUR API KEY'
  # Uncomment the following line to set a prefix for the API key, e.g. 'Bearer' (defaults to nil)
  #config.api_key_prefix['Apikey'] = 'Bearer'
end

api_instance = CloudmersiveConvertApiClient::EditPdfApi.new

watermark_text = 'watermark_text_example' # String | Watermark text to add to the PDF (required)

input_file = File.new('/path/to/inputfile') # File | Input file to perform the operation on.

opts = { 
  font_name: 'font_name_example', # String | Font Family Name for the watermark text; default is Times New Roman
  font_size: 8.14, # Float | Font Size in points of the text; default is 150
  font_color: 'font_color_example', # String | Font color in hexadecimal or HTML color name; default is Red
  font_transparency: 8.14 # Float | Font transparency between 0.0 (completely transparent) to 1.0 (fully opaque); default is 0.5
}

begin
  #Add a text watermark to a PDF
  result = api_instance.edit_pdf_watermark_text(watermark_text, input_file, opts)
  p result
rescue CloudmersiveConvertApiClient::ApiError => e
  puts "Exception when calling EditPdfApi->edit_pdf_watermark_text: #{e}"
end

Download and copy the /client folder into your Apex project:

Download Apex Client

SwagEditPdfApi api = new SwagEditPdfApi();
SwagClient client = api.getClient();

// Configure API key authorization: Apikey
ApiKeyAuth Apikey = (ApiKeyAuth) client.getAuthentication('Apikey');
Apikey.setApiKey('YOUR API KEY');

Map<String, Object> params = new Map<String, Object>{
    'watermarkText' => 'watermarkText_example',
    'inputFile' => Blob.valueOf('Sample text file\nContents'),
    'fontName' => 'fontName_example',
    'fontSize' => 8.14,
    'fontColor' => 'fontColor_example',
    'fontTransparency' => 8.14
};

try {
    // cross your fingers
    Blob result = api.editPdfWatermarkText(params);
    System.debug(result);
} catch (Swagger.ApiException e) {
    // ...handle your exceptions
}

Install libcurl in your C/C++ project:

libcurl/7.75.0
CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
     curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
     curl_easy_setopt(curl, CURLOPT_URL, "https://api.cloudmersive.com/convert/edit/pdf/watermark/text");
     curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
     curl_easy_setopt(curl, CURLOPT_DEFAULT_PROTOCOL, "https");
     struct curl_slist *headers = NULL;
     headers = curl_slist_append(headers, "watermarkText: <string>");
     headers = curl_slist_append(headers, "fontName: <string>");
     headers = curl_slist_append(headers, "fontSize: <number>");
     headers = curl_slist_append(headers, "fontColor: <string>");
     headers = curl_slist_append(headers, "fontTransparency: <number>");
     headers = curl_slist_append(headers, "Content-Type: multipart/form-data");
     headers = curl_slist_append(headers, "Apikey: YOUR-API-KEY-HERE");
     curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
     curl_mime *mime;
     curl_mimepart *part;
     mime = curl_mime_init(curl);
     part = curl_mime_addpart(mime);
     curl_mime_name(part, "inputFile");
     curl_mime_filedata(part, "/path/to/file");
     curl_easy_setopt(curl, CURLOPT_MIMEPOST, mime);
     res = curl_easy_perform(curl);
     curl_mime_free(mime);
}
curl_easy_cleanup(curl);
curl --location --request POST 'https://api.cloudmersive.com/convert/edit/pdf/watermark/text' \
--header 'watermarkText: <string>' \
--header 'fontName: <string>' \
--header 'fontSize: <number>' \
--header 'fontColor: <string>' \
--header 'fontTransparency: <number>' \
--header 'Content-Type: multipart/form-data' \
--header 'Apikey: YOUR-API-KEY-HERE' \
--form 'inputFile=@"/path/to/file"'
import Foundation
#if canImport(FoundationNetworking)
import FoundationNetworking
#endif

var semaphore = DispatchSemaphore (value: 0)

let parameters = [
     [
          "key": "inputFile",
          "src": "/path/to/file",
          "type": "file"
     ]] as [[String : Any]]

let boundary = "Boundary-\(UUID().uuidString)"
var body = ""
var error: Error? = nil
for param in parameters {
     if param["disabled"] == nil {
          let paramName = param["key"]!
          body += "--\(boundary)\r\n"
          body += "Content-Disposition:form-data; name=\"\(paramName)\""
          if param["contentType"] != nil {
               body += "\r\nContent-Type: \(param["contentType"] as! String)"
          }
          let paramType = param["type"] as! String
          if paramType == "text" {
               let paramValue = param["value"] as! String
               body += "\r\n\r\n\(paramValue)\r\n"
          } else {
               let paramSrc = param["src"] as! String
               let fileData = try NSData(contentsOfFile:paramSrc, options:[]) as Data
               let fileContent = String(data: fileData, encoding: .utf8)!
               body += "; filename=\"\(paramSrc)\"\r\n"
                 + "Content-Type: \"content-type header\"\r\n\r\n\(fileContent)\r\n"
          }
     }
}
body += "--\(boundary)--\r\n";
let postData = body.data(using: .utf8)

var request = URLRequest(url: URL(string: "https://api.cloudmersive.com/convert/edit/pdf/watermark/text")!,timeoutInterval: Double.infinity)
request.addValue("<string>", forHTTPHeaderField: "watermarkText")
request.addValue("<string>", forHTTPHeaderField: "fontName")
request.addValue("<number>", forHTTPHeaderField: "fontSize")
request.addValue("<string>", forHTTPHeaderField: "fontColor")
request.addValue("<number>", forHTTPHeaderField: "fontTransparency")
request.addValue("multipart/form-data", forHTTPHeaderField: "Content-Type")
request.addValue("YOUR-API-KEY-HERE", forHTTPHeaderField: "Apikey")
request.addValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

request.httpMethod = "POST"
request.httpBody = postData

let task = URLSession.shared.dataTask(with: request) { data, response, error in 
     guard let data = data else {
          print(String(describing: error))
          semaphore.signal()
          return
     }
     print(String(data: data, encoding: .utf8)!)
     semaphore.signal()
}

task.resume()
semaphore.wait()

This code snippet uses the built-in JavaScript XHR request capability

var data = new FormData();
data.append("inputFile", fileInput.files[0], "file");
 
var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function() {
     if(this.readyState === 4) {
          console.log(this.responseText);
     }
});

xhr.open("POST", "https://api.cloudmersive.com/convert/edit/pdf/watermark/text");
xhr.setRequestHeader("watermarkText", "<string>");
xhr.setRequestHeader("fontName", "<string>");
xhr.setRequestHeader("fontSize", "<number>");
xhr.setRequestHeader("fontColor", "<string>");
xhr.setRequestHeader("fontTransparency", "<number>");

xhr.setRequestHeader("Apikey", "YOUR-API-KEY-HERE");

xhr.send(data);
package main

import (
     "fmt"
     "bytes"
     "mime/multipart"
     "os"
     "path/filepath"
     "io"
     "net/http"
     "io/ioutil"
)

func main() {

     url := "https://api.cloudmersive.com/convert/edit/pdf/watermark/text"
     method := "POST"

     payload := &bytes.Buffer{}
     writer := multipart.NewWriter(payload)
     file, errFile1 := os.Open("/path/to/file")
     defer file.Close()
     part1,
         errFile1 := writer.CreateFormFile("inputFile",filepath.Base("/path/to/file"))
     _, errFile1 = io.Copy(part1, file)
     if errFile1 != nil {
          fmt.Println(errFile1)
          return
     }
     err := writer.Close()
     if err != nil {
          fmt.Println(err)
          return
     }


     client := &http.Client {
     }
     req, err := http.NewRequest(method, url, payload)

     if err != nil {
          fmt.Println(err)
          return
     }
     req.Header.Add("watermarkText", "<string>")
     req.Header.Add("fontName", "<string>")
     req.Header.Add("fontSize", "<number>")
     req.Header.Add("fontColor", "<string>")
     req.Header.Add("fontTransparency", "<number>")
     req.Header.Add("Content-Type", "multipart/form-data")
     req.Header.Add("Apikey", "YOUR-API-KEY-HERE")

     req.Header.Set("Content-Type", writer.FormDataContentType())
     res, err := client.Do(req)
     if err != nil {
          fmt.Println(err)
          return
     }
     defer res.Body.Close()

     body, err := ioutil.ReadAll(res.Body)
     if err != nil {
          fmt.Println(err)
          return
     }
     fmt.Println(string(body))
}

Walkthrough Video