# Setting User-Agent

### Introduction <a href="#id-0-toc-title" id="id-0-toc-title"></a>

You can set a custom **User-Agent** string for remote browsers. This allows you to emulate different browsers, devices, or operating systems, which is useful for testing, web scraping, or accessing content optimized for specific platforms.

#### Configuring a Custom User-Agent <a href="#id-1-toc-title" id="id-1-toc-title"></a>

The User-Agent must be set when launching the browser, affecting all pages opened by that browser instance. Below are the steps to configure a custom User-Agent.

**1. Configure the Custom User-Agent for the Browser**

Here is a C# example showing how to configure and use a custom User-Agent with a browser managed by **CloudBrowser**.

<pre class="language-csharp"><code class="lang-csharp">using System;
using System.Net.Http;
using System.Threading.Tasks;
using PuppeteerSharp;

public class Program
{
    public static async Task Main(string[] args)
    {
        var serverUrl = "https://production.cloudbrowser.ai/api/v1/Browser/Open";
        var apiToken = "your-api-token"; // Replace with your actual API token

        // Define the custom User-Agent
        var userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36"; // Replace with your desired User-Agent

<strong>        // Create an HttpClient and include the API token in the request headers
</strong>        var httpClient = new HttpClient();
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiToken);

        // Request the WebSocket endpoint of the remote browser
        var browserWSEndpoint = await httpClient.GetStringAsync(serverUrl);
        
        // Connect to the remote browser
        var browser = await Puppeteer.ConnectAsync(new ConnectOptions
        {
            BrowserWSEndpoint = browserWSEndpoint
        });

        // Create a new page
        var page = await browser.NewPageAsync();

        // Set the custom User-Agent
        await page.SetUserAgentAsync(userAgent);

        // Navigate to a URL to verify the User-Agent
        await page.GoToAsync("https://www.whatismybrowser.com/");

        // Close the browser
        await browser.CloseAsync();
    }
}
</code></pre>

**2. Code Explanation**

1. **Define the Custom User-Agent**: Set the `userAgent` variable with the desired User-Agent string.

```
   var userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36"; // Replace with your desired User-Agent
```

2. **Connect to the Server**: Get the WebSocket endpoint for the browser from the **CloudBrowser** API.

```
   var httpClient = new HttpClient();
   var browserWSEndpoint = await httpClient.GetStringAsync(serverUrl);
```

3. **Connect to the Remote Browser**: Use `Puppeteer.ConnectAsync` to connect to the browser.

```
   var browser = await Puppeteer.ConnectAsync(new ConnectOptions
   {
       BrowserWSEndpoint = browserWSEndpoint
   });
```

4. **Create a New Page**: Create a new page instance in the browser.

```
   var page = await browser.NewPageAsync();
```

5. **Set the Custom User-Agent**: Use `page.SetUserAgentAsync` to apply the custom User-Agent string to the page.

```
   await page.SetUserAgentAsync(userAgent);
```

6. **Navigate and Verify**: Navigate to a site like `https://www.whatismybrowser.com/` to verify the User-Agent.

```
   await page.GoToAsync("https://www.whatismybrowser.com/");
```

7. **Close the Browser**: Close the browser when finished.

```
   await browser.CloseAsync();
```

#### Additional Considerations <a href="#id-4-toc-title" id="id-4-toc-title"></a>

* **User-Agent Formatting**: Ensure the User-Agent string is correctly formatted to reflect the desired browser and device characteristics.
* **Compatibility**: Verify that the User-Agent string does not conflict with other browser settings or functionalities.


---

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