Skip to main content

Understanding SERVICE_SID_TYPE_UNRESTRICTED in Azure DevOps Agent Configuration

When configuring self-hosted Azure DevOps agents on Windows, one often-overlooked setting can significantly improve security and resource access control: the SERVICE_SID_TYPE_UNRESTRICTED.

I first learned about this when configuring a new build agent on our build server. While going through the configuration steps, I got an extra question if I wanted to enable the SERVICE_SID_TYPE_UNRESTRICTED for the agent service. As I had no clue what this option means, I decided to dive in and write a blog post about it.

What is SERVICE_SID_TYPE_UNRESTRICTED?

Windows services can be assigned a Service SID (Security Identifier) to help manage access to resources. By default, Azure DevOps agents run with SERVICE_SID_TYPE_NONE, which means no service-specific SID is added to the process token.

Setting the SID type to UNRESTRICTED adds a unique SID like NT SERVICE\vstsagent.{tenant}.{pool}.{agent} to the agent's process token. This allows you to:

  • Grant access to local resources (e.g., folders, certificates) specifically to that agent.

  • Isolate permissions between multiple agents on the same machine.

  • Avoid managing separate user accounts or passwords for each agent.

How to enable it

During the interactive configuration of the agent (via config.cmd), you can specify this SID type:

.\config.cmd --unattended --enableservicesidtypeunrestricted

Or, if you're using the interactive prompt, it may ask whether to set the SID type to UNRESTRICTED (as you can see in the screenshot above).

Why this matters

Here’s why this setting is especially useful:

  • Security: You can restrict access to sensitive resources (like secrets or build artifacts) to only the specific agent service.

  • Scalability: Multiple agents can run under the same account but still be isolated via their unique SIDs.

  • Maintainability: Reduces the need for managing separate service accounts or passwords.

More information

Deploy an Azure Pipelines agent on Windows - Azure Pipelines | Microsoft Learn

Agent runnig on Windows as a service should set service SID type to SERVICE_SID_TYPE_UNRESTRICTED · Issue #2814 · microsoft/azure-pipelines-agent

Labels:

Popular posts from this blog

Podman– Command execution failed with exit code 125

After updating WSL on one of the developer machines, Podman failed to work. When we took a look through Podman Desktop, we noticed that Podman had stopped running and returned the following error message: Error: Command execution failed with exit code 125 Here are the steps we tried to fix the issue: We started by running podman info to get some extra details on what could be wrong: >podman info OS: windows/amd64 provider: wsl version: 5.3.1 Cannot connect to Podman. Please verify your connection to the Linux system using `podman system connection list`, or try `podman machine init` and `podman machine start` to manage a new Linux VM Error: unable to connect to Podman socket: failed to connect: dial tcp 127.0.0.1:2655: connectex: No connection could be made because the target machine actively refused it. That makes sense as the podman VM was not running. Let’s check the VM: >podman machine list NAME         ...
Read more

Azure DevOps/ GitHub emoji

I’m really bad at remembering emoji’s. So here is cheat sheet with all emoji’s that can be used in tools that support the github emoji markdown markup: All credits go to rcaviers who created this list.
Read more

VS Code Planning mode

After the introduction of Plan mode in Visual Studio , it now also found its way into VS Code. Planning mode, or as I like to call it 'Hannibal mode', extends GitHub Copilot's Agent Mode capabilities to handle larger, multi-step coding tasks with a structured approach. Instead of jumping straight into code generation, Planning mode creates a detailed execution plan. If you want more details, have a look at my previous post . Putting plan mode into action VS Code takes a different approach compared to Visual Studio when using plan mode. Instead of a configuration setting that you can activate but have limited control over, planning is available as a separate chat mode/agent: I like this approach better than how Visual Studio does it as you have explicit control when plan mode is activated. Instead of immediately diving into execution, the plan agent creates a plan and asks some follow up questions: You can further edit the plan by clicking on ‘Open in Editor’: ...
Read more