# ASP.NET Core > Convert HTML and DOCX to PDF in an ASP.NET Core MVC app with the DocumentProcessing NuGet package: create a security profile, configure OAuth and call Convert. - **Product:** DS Server - **Section:** Documentation - **Kind:** Topic - **Path:** DS Server > Getting Started > Document Processing > ASP.NET Core - **3400 words** - **Web URL:** https://docs.textcontrol.com/ds-server/getting-started/document-processing/aspnet-core/ - **LLMs URL:** https://docs.textcontrol.com/ds-server/getting-started/document-processing/aspnet-core/llms.txt - **LLMs-Full URL:** https://docs.textcontrol.com/ds-server/getting-started/document-processing/aspnet-core/llms-full.txt --- Your first DocumentProcessing application is an ASP.NET Core web application that sends an HTML document to DS Server and returns the PDF that comes back to the browser. You create a security profile in the admin portal, install the `TXTextControl.DocumentServices.DocumentProcessing` package from nuget.org and write one controller action. The document processing itself happens on DS Server, so your application needs no TX Text Control engine of its own. ### Prerequisites - **A DS Server.** Either a DS Server of your own that is installed as the [Installation Guide](https://docs.textcontrol.com/ds-server/installation/llms-full.txt) describes and registered with a serial number as [Licensing](https://docs.textcontrol.com/ds-server/administration/licensing/llms-full.txt) shows, or a [trial token](https://docs.textcontrol.com/ds-server/getting-started/trial-token/llms-full.txt) for the trial server `https://trial.dsserver.io`. An unregistered server refuses every DocumentProcessing request. - **The .NET 10 SDK.** The steps were written with Visual Studio 2026 and .NET 10 (Long Term Support). The package also supports .NET 8, and you can use the .NET CLI with any editor instead of Visual Studio. With a trial token, skip the next section: the trial profile already exists. ### Create a Security Profile Your application authenticates at DS Server with the client ID and the client secret of a *security profile*, the OAuth credentials that the admin creates for each application in the admin portal. The admin portal is the root URL of your DS Server, such as `http://localhost:5000`, and asks for the admin user name and password. 1. Choose **Security Profiles** in the navigation bar, then click **+ Create new profile**. 2. Enter a name, such as `MyDsApp`, and click **Create**. 3. The page now shows the profile with its **Client ID** and **Client Secret**. Copy both values with the copy buttons next to them, and click **Done**. ![The Edit Security Profile page of the admin portal right after Create: the profile name, an empty list of authorized redirect URIs, the Allow "Client Credentials" grant type switch turned off, the expiry date, the client ID starting with dsserver., the client secret and the Done button.](https://docs.textcontrol.com/assets/img/ds-server/portal-profile-details.48eafb12.webp) 4. In the list of profiles, click the **Edit profile** icon of the new profile, turn on **Allow "Client Credentials" grant type** and click **Save**. The *client credentials* grant type lets a server application request an access token with the client ID and the client secret alone, without redirecting a user. It is off by default for every new profile; [OAuth Grant Types](https://docs.textcontrol.com/ds-server/administration/oauth-grant-types/llms-full.txt) explains the setting. A new installation of DS Server has OAuth disabled and accepts requests without an access token. The application works either way, but only with OAuth enabled does DS Server check the credentials. Turn it on with the switch at the top of the **Security Profiles** page, as [Enable OAuth](https://docs.textcontrol.com/ds-server/administration/oauth/llms-full.txt) shows. ### Create the Project Use either Visual Studio or the .NET CLI. #### Visual Studio 1. In Visual Studio 2026, create a new project by choosing **Create a new project**. 2. Select **ASP.NET Core Web App (Model-View-Controller)** as the project template and confirm with **Next**. 3. Enter `MyDsApp` as the project name, choose a location and confirm with **Next**. 4. Choose **.NET 10.0 (Long Term Support)** as the **Framework** and confirm with **Create**. #### .NET CLI 1. Open a terminal and create a new MVC application: ```bash dotnet new mvc -n MyDsApp ``` 2. Change to the project directory: ```bash cd MyDsApp ``` ### Install the NuGet Package `TXTextControl.DocumentServices.DocumentProcessing` is published on nuget.org. Version 5.0.0 is meant for DS Server 5.0 and targets .NET 8 and .NET 10. It sends your documents to the DocumentProcessing Web API and returns the results as byte arrays. #### Visual Studio 1. In **Solution Explorer**, select your project and choose **Manage NuGet Packages...** from the **Project** main menu. 2. Select **nuget.org** as the **Package source**. 3. Browse for `TXTextControl.DocumentServices.DocumentProcessing` and install it. #### .NET CLI Add the package to the project: ```bash dotnet add package TXTextControl.DocumentServices.DocumentProcessing ``` ### Configure the Connection Open *appsettings.json* and add a `DSServer` section with the address of DS Server and the credentials of the security profile: ```json { "Logging": { "LogLevel": { "Default": "Information", "Microsoft.AspNetCore": "Warning" } }, "AllowedHosts": "*", "DSServer": { "ServiceUrl": "http://localhost:5000", "ClientId": "", "ClientSecret": "" } } ``` Replace `http://localhost:5000` with the address of your DS Server, or with `https://trial.dsserver.io` when you use a trial token, and the placeholders with the client ID and the client secret. The client secret gives access to your DS Server: in a real application, keep it out of source control, for example in an environment variable such as `DSServer__ClientSecret`. ### Write the Code In the *Controllers* folder, add a class *DocumentController.cs* with the following code: ```csharp using System.Text; using Microsoft.AspNetCore.Mvc; using TXTextControl.DocumentServices.DocumentProcessing; using TXTextControl.DocumentServices.DocumentProcessing.OAuth; namespace MyDsApp.Controllers; public class DocumentController : Controller { private readonly IConfiguration _configuration; public DocumentController(IConfiguration configuration) { _configuration = configuration; } public async Task Pdf() { // Read the connection settings from appsettings.json IConfigurationSection dsServer = _configuration.GetSection("DSServer"); // Request an access token with the credentials of the security profile var oauthSettings = new OAuthSettings(dsServer["ClientId"], dsServer["ClientSecret"]); var documentProcessing = new DocumentProcessing(dsServer["ServiceUrl"], oauthSettings); // The document to convert: HTML, encoded as UTF-8 byte[] html = Encoding.UTF8.GetBytes( "

Hello DS Server

This PDF was created by DS Server.

"); // Send the document to DS Server and receive it as PDF byte[] pdf = await documentProcessing.Convert(html, ReturnFormat.PDF); return File(pdf, "application/pdf", "sample.pdf"); } } ``` #### What the Code Does - `OAuthSettings`, in the `TXTextControl.DocumentServices.DocumentProcessing.OAuth` namespace, holds the client ID and the client secret. Without a third argument, the redirect URI, the package uses the client credentials grant type. - The [DocumentProcessing](https://docs.textcontrol.com/ds-server/reference/dotnet-api/txtextcontrol-documentservices-documentprocessing/llms-full.txt) constructor takes the service URL and the OAuth settings. It requests the access token from `/oauth/token` right away and sends it with every later request. - `Convert` sends the document to the endpoint `POST /documentprocessing/document/convert` and returns the converted document as a byte array. The `ReturnFormat` value selects the format: `PDF`, `PDFA`, `DOC`, `DOCX`, `RTF`, `TX`, `TXT` or `HTML`. DS Server detects the format of the input document itself. - `File` returns the PDF to the browser as a download named *sample.pdf*. An access token expires after one hour, and the constructor requests it only once. That is why the action creates a new `DocumentProcessing` instance for each request instead of keeping one for the lifetime of the application. ### Run the Application 1. Start DS Server if it runs on your machine. 2. Start the application: in Visual Studio, press **F5**; with the .NET CLI, run `dotnet run` in the project directory. The console shows the address the application listens on, such as `http://localhost:5034`. DS Server listens on port 5000 by default, so the two don't collide. 3. Open `/Document/Pdf` below that address in the browser, for example `http://localhost:5034/Document/Pdf`. The browser downloads *sample.pdf*, which shows the heading "Hello DS Server" and the paragraph below it. ### Convert a Word Document `Convert` takes any document format that DS Server can load, such as DOCX, RTF, HTML or PDF; [Supported File Formats](https://docs.textcontrol.com/ds-server/overview/file-formats/llms-full.txt) lists them for the Core and Classic builds. To convert a Word document instead of the HTML string: 1. Create a folder *App\_Data* in the project and copy a Word document into it as *sample.docx*. 2. Add a second action to `DocumentController`: ```csharp public async Task Word() { IConfigurationSection dsServer = _configuration.GetSection("DSServer"); var oauthSettings = new OAuthSettings(dsServer["ClientId"], dsServer["ClientSecret"]); var documentProcessing = new DocumentProcessing(dsServer["ServiceUrl"], oauthSettings); // Read a Word document from the project folder byte[] docx = await System.IO.File.ReadAllBytesAsync("App_Data/sample.docx"); byte[] pdf = await documentProcessing.Convert(docx, ReturnFormat.PDF); return File(pdf, "application/pdf", "sample.pdf"); } ``` 1. Open `/Document/Word` in the browser. The path *App\_Data/sample.docx* is relative to the working directory, which is the project directory when you start the application from Visual Studio or with `dotnet run`. The other methods of `DocumentProcessing` follow the same pattern: `Merge` fills a template with JSON data, `Append` combines documents, `Thumbnails` renders page images and `PDF.Create` creates a PDF with metadata. [ASP.NET Core](https://docs.textcontrol.com/ds-server/client-libraries/aspnet-core/#documentprocessing) in Client-Side Libraries lists them with the endpoints they call. ### Troubleshooting The package reports errors as exceptions. A request that DS Server rejects throws a `ServiceRequestException` with the status code; a failed token request in the constructor throws an `AggregateException` whose inner exception holds the OAuth error. - **DS Server is not registered.** DS Server has no license yet: ```text POST request to document/convert failed: DS Server is not registered. (Status code 400 / BadRequest) ``` Register the server with your serial number or the trial serial number, as [Licensing](https://docs.textcontrol.com/ds-server/administration/licensing/llms-full.txt) describes. - **The grant type is not allowed.** The security profile doesn't allow the client credentials grant type: ```text OAuth access token request failed. error: "unsupported_grant_type", error_description: "This security profile does not allow the specified grant type. (client_credentials)" ``` Turn on **Allow "Client Credentials" grant type** in the profile, as step 4 of [Create a Security Profile](#create-a-security-profile) shows. The error `invalid_client` means that the client ID or the client secret in *appsettings.json* is wrong. - **The request is unauthorized.** DS Server has OAuth enabled and rejects the access token: ```text POST request to document/convert failed for unknown reasons. Status code 401 / Unauthorized. ``` Check whether the security profile has an expiry date in the past. Create the instance with the constructor, as the sample does: `DocumentProcessing.CreateInstanceAsync` in version 5.0.0 of the package requests an access token but doesn't send it with the later requests. - **The connection is refused.** DS Server doesn't run at the service URL, for example `Connection refused (localhost:5000)`. Check that DS Server is started and that `ServiceUrl` names its address and port. ### Next Steps - [Web API](https://docs.textcontrol.com/ds-server/getting-started/document-processing/web-api/llms-full.txt): the same conversion with plain HTTP requests, from any language. - [Merging Templates](https://docs.textcontrol.com/ds-server/document-processing/mail-merge/llms-full.txt): merge templates with JSON data. - [Converting Documents](https://docs.textcontrol.com/ds-server/document-processing/converting/llms-full.txt): formats, options and form fields. - [ASP.NET Core](https://docs.textcontrol.com/ds-server/client-libraries/aspnet-core/llms-full.txt): every package for ASP.NET Core and its settings. - [Document Editor](https://docs.textcontrol.com/ds-server/getting-started/document-editor/aspnet-core/llms-full.txt): let users edit documents in the browser. --- ## Nearby - **Previous:** [Document Processing](https://docs.textcontrol.com/ds-server/getting-started/document-processing/llms-full.txt) - **Next:** [Web API](https://docs.textcontrol.com/ds-server/getting-started/document-processing/web-api/llms-full.txt)