---
title: "Configuring a Proxy Server"
slug: "configuring-a-proxy-server"
updated: 2024-10-10T11:06:20Z
published: 2024-10-10T11:06:20Z
canonical: "docs.onespan.com/configuring-a-proxy-server"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.onespan.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Configuring a Proxy Server

[Java SDK](/v1/docs/configuring-a-proxy-server#java-sdk) [.NET SDK](/v1/docs/configuring-a-proxy-server#net-sdk) [REST API](/v1/docs/configuring-a-proxy-server#rest-api)

## Java SDK

To download the full code sample see our [Code Share](https://community.onespan.com/documentation/onespan-sign/codeshare/proxy-configuration-java-sdk/) site.

A proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. With OneSpan Sign, you can make API calls via a proxy server.

To make API calls to OneSpan Sign using a proxy server, you will need to build a ProxyConfiguration object. You will need to pass the proxy server's address and port number to the withHttpHost() and withHttpPort() methods respectively.

```java
ProxyConfiguration httpProxyConfiguration = ProxyConfigurationBuilder.newProxyConfiguration()
                .withHttpHost("serverAddress") //e.g. localhost
                .withHttpPort(portNumber) //e.g. 8001
                .build();
```

### Adding Authentication

If your proxy server is configured to request additional authentication, such as a username and password, you need to add these to your ProxyConfiguration object. The following code sample provides a way to do so.

```java
ProxyConfiguration httpProxyConfiguration = ProxyConfigurationBuilder.newProxyConfiguration()
                .withHttpHost("serverAddress")
                .withHttpPort(portNumber)
                .withCredentials("httpUser", "httpPwd")
                .build();
```

### Building Your EslClient

The final step is to create your EslClient object.

For security reasons, trusting all certificates should not be enabled.

```java
boolean allowAllSSLCertificates = false;		
EslClient client = new EslClient(API_KEY, API_URL, allowAllSSLCertificates, httpProxyConfiguration);
```

## .NET SDK

To download the full code sample see our [Code Share](https://community.onespan.com/documentation/onespan-sign/codeshare/proxy-configuration-net-sdk/) site.

A proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. With OneSpan Sign, you can make API calls via a proxy server.

To make API calls to OneSpan Sign using a proxy server, you will need to build a ProxyConfiguration object. You will need to pass the proxy server's address and port number to the withHttpHost() and withHttpPort() methods respectively.

```csharp
ProxyConfiguration httpProxyConfiguration = ProxyConfigurationBuilder.newProxyConfiguration()
                .WithHttpHost("serverAddress") //e.g. localhost
                .WithHttpPort(portNumber) //e.g. 8001
                .Build();
```

### Adding Authentication

If your proxy server is configured to request additional authentication, such as a username and password, you need to add these to your ProxyConfiguration object. The following code sample provides a way to do so.

```csharp
ProxyConfiguration httpProxyConfiguration = ProxyConfigurationBuilder.newProxyConfiguration()
                .WithHttpHost("serverAddress")
                .WithHttpPort(portNumber)
                .WithCredentials("httpUser", "httpPwd")
                .Build();
```

### Building Your EslClient

The final step is to create your EslClient object.

For security reasons, trusting all certificates should not be enabled.

```csharp
Boolean allowAllSSLCertificates = false;		
EslClient client = new EslClient(API_KEY, API_URL, allowAllSSLCertificates, httpProxyConfiguration);
```

## REST API

To download the full code sample see our [Code Share](https://community.onespan.com/documentation/onespan-sign/codeshare/proxy-configuration-rest-api/) site.

A proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. With OneSpan Sign, you can make API calls via a proxy server.

To make API calls to OneSpan Sign using a proxy server, you will need to build a ProxyConfiguration object. You will need to pass the proxy server's address and port number to the withHttpHost() and withHttpPort() methods respectively.

### Building a WebProxy Object

The first step in making API calls to OneSpan Sign through a proxy server is to build a WebProxy object. When doing this set, the UseDefaultCredentials property to true when requests made by your WebProxy object should, if requested by the server, be authenticated using the credentials of the currently logged on user. Otherwise, set this property to false.

```csharp
string proxyUri = string.Format("{0}:{1}", "serverAddress", portNumber); //e.g. 13.1.25.80:8200 
WebProxy proxy = new WebProxy(proxyUri, false)
{
        UseDefaultCredentials = false
};
```

### Creating a HttpClient

Next, you will need to create the HttpClient that will be used to send requests to OneSpan Sign. In this example, you will need to create one with a specific handler. Note that:

- The Proxy property sets the proxy information used by the handler.
- The PreAuthenticate property indicates the handler will send an Authorization header with the request.

```csharp
HttpClient client = null;
HttpClientHandler httpClientHandler = new HttpClientHandler()
 {
        Proxy = proxy,
        PreAuthenticate = true,
        UseDefaultCredentials = false,
};
```

### Adding Authentication

If your proxy server is configured to request additional authentication, such as a username and password, you need to add these to your ProxyConfiguration object. The following code sample provides a way to do so.

```csharp
string httpUserName = "httpUser", httpPassword = "httpPwd";
httpClientHandler.Credentials = new NetworkCredential(httpUserName, httpPassword);
```

### Initializing a New Instance of the HttpClient

The last step is to initialize a new instance of the HttpClient class with the specific handler.

```csharp
client = new HttpClient(httpClientHandler);
```