2 Credits

DOCX templating API for Word-based document generation

Populate Word DOCX templates with JSON data and generate polished documents for automated workflows.

Keep template authoring in Word

Let operations, legal, and business teams maintain DOCX templates in Word while your application injects runtime data through a simple HTTP API.

Fill text, loops, nested data, and images

Generate personalized documents from JSON model data, including repeated sections and richer placeholders for real document-generation workflows.

Built for automated document pipelines

Use REST, Postman, JavaScript, Python, Java, C#, PHP, or HTTP to create proposals, agreements, and internal documents without self-hosting a document templating system.

Try it out

This example fills a DOCX template with JSON data and returns a generated DOCX document.

Try it out in three steps

Create a Word template named template.docx and add placeholders like Hello {name}, Company: {company}, and Date: {date}.
Run the code from the same folder.
Open result.docx to verify the placeholders were replaced.

Advanced API

curl -X POST https://api.nutrient.io/process_office_template \
  -H "Authorization: Bearer your_api_key_here" \
  -o result.docx \
  --fail \
  -F 'document=@template.docx;type=application/vnd.openxmlformats-officedocument.wordprocessingml.document' \
  -F 'model={"name":"Alex","company":"Acme","date":"2026-04-10"}'

curl -X POST https://api.nutrient.io/process_office_template ^
  -H "Authorization: Bearer your_api_key_here" ^
  -o result.docx ^
  --fail ^
  -F "document=@template.docx;type=application/vnd.openxmlformats-officedocument.wordprocessingml.document" ^
  -F "model={\"name\":\"Alex\",\"company\":\"Acme\",\"date\":\"2026-04-10\"}"

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.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 MediaType mediaType = MediaType.parse("application/vnd.openxmlformats-officedocument.wordprocessingml.document");
    final RequestBody body = new MultipartBody.Builder()
      .setType(MultipartBody.FORM)
      .addFormDataPart(
        "document",
        "template.docx",
        RequestBody.create(
          mediaType,
          new File("template.docx")
        )
      )
      .addFormDataPart(
        "model",
        new JSONObject()
          .put("name", "Alex")
          .put("company", "Acme")
          .put("date", "2026-04-10").toString()
      )
      .build();

    final Request request = new Request.Builder()
      .url("https://api.nutrient.io/process_office_template")
      .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.docx"),
        StandardCopyOption.REPLACE_EXISTING
      );
    } else {
      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/process_office_template");

      var request = new RestRequest(Method.POST)
        .AddHeader("Authorization", "Bearer your_api_key_here")
        .AddFile("document", "template.docx")
        .AddParameter("model", new JsonObject
        {
          ["name"] = "Alex",
          ["company"] = "Acme",
          ["date"] = "2026-04-10"
        }.ToString());

      request.AdvancedResponseWriter = (responseStream, response) =>
      {
        if (response.StatusCode == HttpStatusCode.OK)
        {
          using (responseStream)
          {
            using var outputFileWriter = File.OpenWrite("result.docx");
            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('document', fs.createReadStream('template.docx'), {
  contentType: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
  filename: 'template.docx'
})
formData.append('model', JSON.stringify({
  name: 'Alex',
  company: 'Acme',
  date: '2026-04-10'
}))

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

    response.data.pipe(fs.createWriteStream('result.docx'))
  } 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 json
import requests

response = requests.request(
  'POST',
  'https://api.nutrient.io/process_office_template',
  headers = {
    'Authorization': 'Bearer your_api_key_here'
  },
  files = {
    'document': ('template.docx', open('template.docx', 'rb'), 'application/vnd.openxmlformats-officedocument.wordprocessingml.document')
  },
  data = {
    'model': json.dumps({
      'name': 'Alex',
      'company': 'Acme',
      'date': '2026-04-10'
    })
  },
  stream = True
)

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

<?php

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

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.nutrient.io/process_office_template',
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_POSTFIELDS => array(
    'document' => new CURLFILE('template.docx', 'application/vnd.openxmlformats-officedocument.wordprocessingml.document', 'template.docx'),
    'model' => '{
      "name": "Alex",
      "company": "Acme",
      "date": "2026-04-10"
    }'
  ),
  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/process_office_template HTTP/1.1
Content-Type: multipart/form-data; boundary=--customboundary
Authorization: Bearer your_api_key_here

--customboundary
Content-Disposition: form-data; name="document"; filename="template.docx"
Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document

(template.docx data)
--customboundary
Content-Disposition: form-data; name="model"

{"name":"Alex","company":"Acme","date":"2026-04-10"}
--customboundary--

curl -X POST https://api.nutrient.io/process_office_template \
  -H "Authorization: Bearer your_api_key_here" \
  -o result.docx \
  --fail \
  -F 'document=@template.docx;type=application/vnd.openxmlformats-officedocument.wordprocessingml.document' \
  -F 'model={"config":{"delimiter":{"start":"{{","end":"}}"}},"model":{"name":"Alex","company":"Acme","date":"2026-04-10"}}'

curl -X POST https://api.nutrient.io/process_office_template ^
  -H "Authorization: Bearer your_api_key_here" ^
  -o result.docx ^
  --fail ^
  -F "document=@template.docx;type=application/vnd.openxmlformats-officedocument.wordprocessingml.document" ^
  -F "model={\"config\":{\"delimiter\":{\"start\":\"{{\",\"end\":\"}}\"}},\"model\":{\"name\":\"Alex\",\"company\":\"Acme\",\"date\":\"2026-04-10\"}}"

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.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 MediaType mediaType = MediaType.parse("application/vnd.openxmlformats-officedocument.wordprocessingml.document");
    final JSONObject model = new JSONObject()
      .put("config", new JSONObject()
        .put("delimiter", new JSONObject()
          .put("start", "{{")
          .put("end", "}}")
        )
      )
      .put("model", new JSONObject()
        .put("name", "Alex")
        .put("company", "Acme")
        .put("date", "2026-04-10")
      );

    final RequestBody body = new MultipartBody.Builder()
      .setType(MultipartBody.FORM)
      .addFormDataPart(
        "document",
        "template.docx",
        RequestBody.create(
          mediaType,
          new File("template.docx")
        )
      )
      .addFormDataPart("model", model.toString())
      .build();

    final Request request = new Request.Builder()
      .url("https://api.nutrient.io/process_office_template")
      .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.docx"),
        StandardCopyOption.REPLACE_EXISTING
      );
    } else {
      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/process_office_template");

      var request = new RestRequest(Method.POST)
        .AddHeader("Authorization", "Bearer your_api_key_here")
        .AddFile("document", "template.docx")
        .AddParameter("model", new JsonObject
        {
          ["config"] = new JsonObject
          {
            ["delimiter"] = new JsonObject
            {
              ["start"] = "{{",
              ["end"] = "}}"
            }
          },
          ["model"] = new JsonObject
          {
            ["name"] = "Alex",
            ["company"] = "Acme",
            ["date"] = "2026-04-10"
          }
        }.ToString());

      request.AdvancedResponseWriter = (responseStream, response) =>
      {
        if (response.StatusCode == HttpStatusCode.OK)
        {
          using (responseStream)
          {
            using var outputFileWriter = File.OpenWrite("result.docx");
            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('document', fs.createReadStream('template.docx'), {
  contentType: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
  filename: 'template.docx'
})
formData.append('model', JSON.stringify({
  config: {
    delimiter: {
      start: '{{',
      end: '}}'
    }
  },
  model: {
    name: 'Alex',
    company: 'Acme',
    date: '2026-04-10'
  }
}))

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

    response.data.pipe(fs.createWriteStream('result.docx'))
  } 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 json
import requests

response = requests.request(
  'POST',
  'https://api.nutrient.io/process_office_template',
  headers = {
    'Authorization': 'Bearer your_api_key_here'
  },
  files = {
    'document': ('template.docx', open('template.docx', 'rb'), 'application/vnd.openxmlformats-officedocument.wordprocessingml.document')
  },
  data = {
    'model': json.dumps({
      'config': {
        'delimiter': {
          'start': '{{',
          'end': '}}'
        }
      },
      'model': {
        'name': 'Alex',
        'company': 'Acme',
        'date': '2026-04-10'
      }
    })
  },
  stream = True
)

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

<?php

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

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.nutrient.io/process_office_template',
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_POSTFIELDS => array(
    'document' => new CURLFILE('template.docx', 'application/vnd.openxmlformats-officedocument.wordprocessingml.document', 'template.docx'),
    'model' => '{
      "config": {
        "delimiter": {
          "start": "{{",
          "end": "}}"
        }
      },
      "model": {
        "name": "Alex",
        "company": "Acme",
        "date": "2026-04-10"
      }
    }'
  ),
  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/process_office_template HTTP/1.1
Content-Type: multipart/form-data; boundary=--customboundary
Authorization: Bearer your_api_key_here

--customboundary
Content-Disposition: form-data; name="document"; filename="template.docx"
Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document

(template.docx data)
--customboundary
Content-Disposition: form-data; name="model"

{"config":{"delimiter":{"start":"{{","end":"}}"}},"model":{"name":"Alex","company":"Acme","date":"2026-04-10"}}
--customboundary--

Start now

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Start building with DWS Processor API in minutes — no payment information required.

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Use the following:

DOCX-to-PDF API If the generated Word document also needs PDF output afterward

Office-to-PDF API For broader Word, Excel, and PowerPoint conversion workflows

Get started:

Getting started For API key setup

Postman collection For the fastest first request

REST API reference For endpoint details

Platform resources:

Processor API pricing For credits

Security documentation For document-handling and compliance review

Privacy documentation For data-handling review

Processor API overview For broader DWS evaluation of generation and automation workflows

Security is our top priority

SOC 2 Type 2 audited

Nutrient’s infrastructure is SOC 2 Type 2 audited and GDPR compliant. See our privacy policy and security documentation for details on data handling.

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.

Frequently asked questions

What is a DOCX templating API?

A DOCX templating API fills a Word template with JSON data and returns a generated DOCX document. With Nutrient DWS Processor API, you send the template and a JSON model in one request, and the placeholders are replaced with your values.

How do I add placeholders to a Word template?

Type placeholders directly in the Word document. The default delimiter is a single brace, so {name} maps to name in your JSON model. To use double braces such as {{name}}, send a config.delimiter object with your request.

Can templates include conditional sections and dynamic table rows?

Yes. Conditional blocks show or hide content based on Boolean values in your model, and loop markers inside a Word table add one row per array entry. Generated content reflows across lines, tables, and pages while keeping the formatting from your template.

Do I need Microsoft Office on my server?

No. Templates are processed by the hosted DWS Processor API, so your application only needs to send an HTTP request.

When should I use DOCX templating instead of the PDF generator API?

Use DOCX templating when your documents are designed in Word and the output needs to stay an editable DOCX file. Use the PDF generator API when your layouts are built in HTML and CSS and you need a PDF.

Is there a free DOCX templating API?

Yes. Sign up to receive free Processor API credits and try DOCX templating before choosing a plan. Credit costs per operation are listed on the Processor API pricing page.

Can I use the DOCX templating API for high-volume workloads?

Yes. Processor API pricing is credit-based, with self-serve plans and enterprise options. Contact Sales to discuss volume and enterprise requirements.

Start generating Word documents from templates through one hosted API

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

Try for free