Merge pull request #8291 from MicrosoftDocs/users/sdanie/486886

Basic auth for agent behind proxy

Author: prmerger-automator[bot]

docs/pipelines/agents/proxy.md

@@ -3,7 +3,7 @@ title: Run the agent behind a web proxy
 description: Learn how you can run a v2 private build and release agent behind a web proxy for Azure Pipelines and Team Foundation Server (TFS)
 ms.topic: conceptual
 ms.assetid: 6AC4BA22-9F6F-44B5-BB15-445A7CFD2AD4
-ms.date: 01/25/2023
+ms.date: 09/08/2025
 monikerRange: '<= azure-devops'
 ---
 
@@ -12,7 +12,6 @@ monikerRange: '<= azure-devops'
 [!INCLUDE [version-lt-eq-azure-devops](../../includes/version-lt-eq-azure-devops.md)]
 
 
-
 When your self-hosted agent requires a web proxy, you can inform the agent about the proxy during configuration.
 This allows your agent to connect to Azure Pipelines or TFS through the proxy.
 This in turn allows the agent to get sources and download artifacts.
@@ -74,3 +73,22 @@ Create a `.proxybypass` file in the agent's root directory that specifies regula
 github\.com
 bitbucket\.com
 ```
+
+## Enable Basic authentication for proxy setup
+
+The agent configuration may not be compatible with certain corporate proxy setups that use default NTLM authentication, and you may get `407 authentication errors`. In such cases, you can enable Basic authentication for the proxy by adding the `--usebasicauthforproxy` flag during agent configuration, provided the proxy supports fallback to Basic authentication.
+
+For example:
+
+# [Windows](#tab/windows)
+
+```dotnetcli
+./config.cmd --proxyurl http://proxy.company.com:port --proxyusername <userNamePlaceholder> --proxypassword <passwordPlaceholder> --usebasicauthforproxy
+```
+
+# [macOS and Linux](#tab/unix)
+```
+./config.sh --proxyurl http://proxy.company.com:port --proxyusername <userNamePlaceholder> --proxypassword <passwordPlacehopasswordPlaceholderlder> --usebasicauthforproxy
+```
+
+* * *