> For the complete documentation index, see [llms.txt](https://docs.helmut.de/helmut4-releases/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.helmut.de/helmut4-releases/helmut4-components/streamdesigner/wildcards/undocumented-wildcards-1/environment-variable-bypass-wildcard.md).

# Environment Variable Bypass Wildcard

If you need to use a variable in computing contexts, especially on Windows systems, you may encounter a variable format like `%username%`.\
In Helmut3 and early versions of Helmut4, wildcards were defined using the format `%user.name%`. However, to ensure compatibility with various other systems, this convention has been changed to `{user.name}`.

In modern versions, the stream engine no longer resolves the `%` wildcards in the preview but still converts them.\
If you need to use this format in a "write file" output action or any other node like JavaScript, you can employ an escape wildcard to bypass automatic resolution.

These changes enhance readability and clarity while maintaining the original content's meaning.

### Syntax to bypass

*\[<]environment variable\[>]*

#### Example

<figure><img src="/files/Bb1SDn6DPPosR8c0M6AQ" alt="" width="375"><figcaption><p>Wildcards with {} and %% style</p></figcaption></figure>

<figure><img src="/files/Zt0Q1xMQ159MTqcNrqF6" alt="" width="375"><figcaption><p>Response and compare for resolving bypass</p></figcaption></figure>

{% hint style="info" %}
This wildcard is not an official wildcard and is not documented within Streamdesigner. Consider it as a secret Swiss army knife tool in case it is needed.
{% endhint %}


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.helmut.de/helmut4-releases/helmut4-components/streamdesigner/wildcards/undocumented-wildcards-1/environment-variable-bypass-wildcard.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.