---
title: "About _st (Async module)"
slug: "about-st-async-module"
description: "Learn how to use the _st object for queuing commands in your data activation base script, enhancing your website's tag management and structure."
updated: 2026-04-13T11:32:42Z
published: 2026-04-13T11:32:42Z
canonical: "docs.supermetrics.com/about-st-async-module"
---

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

# About _st (Async module)

Once the data activation base script has been loaded into a website, you’re able to use the synchronous framework by calling, for example:

```javascript
_st.data.getProperty('test').
```

However, if you want to, for example, add some properties to the framework, while the script hasn't necessarily been loaded yet (due to an asynchronous execution), you can use the `_st` object to queue commands to our framework.

## Example basescript

```javascript
(function(a,d,e,b,f,c,s){a[b]=a[b]||function(){a[b].q.push(arguments);};

a[b].q=[];c=d.createElement(e);c.async=1;c.src="//tdn.r42tag.com/lib/"+f+".js";

s=d.getElementsByTagName(e)[0];s.parentNode.insertBefore(c,s);})

(window,document,"script","_st", "9999-v1");

// Add additional settings here (optional)

_st('setPageStructure', 'default|structure');

_st('addTagProperty', 'exampleLocal', 'property');

_st('addTagProperties',  {'example': 'property', 'otherExample': property});

_st('addLocalTagProperties',  {'exampleLocal': 'property', 'otherLocalExample': property});

_st("loadTags");
```

### Explanation

Loading the actual script is the last step op the process. Therefore, the given commands are queued and executed from that queue (`_st()`) after loading the actual script.

The `_st()` command queue doesn't provide the user with the entire API, though. The available commands to queue are listed below.

## Available functions

| Function | Arguments | Description |
| --- | --- | --- |
| `setPageStructure` | 1 to N: `structureElement` (string) | Identify the current page; components are used to form a tree structure. |
| `setEnvironment` | 1: name (string) | Select the environment to use in tag-loading, defaults to “prod.” |
| `addTagProperty` | 1: name (string), 2: value (string) | Add a property to the current tag-set; the property will be forwarded to the remote system. |
| `addLocalTagProperty` | 1: name (string), 2: value (any) | Add a property to the current tag-set; the property will be kept locally in the browser. |
| `addTagProperties` | 1: `propertyObject` (object) | Add all object fields as properties to the current tag-set; the properties will be forwarded to the remote system. |
| `addLocalTagProperties` | 1: `propertyObject` (object) | Add all object fields as properties to the current tag-set; the properties will be kept locally in the browser. |
| `loadTags` | N/A | Call the remote servers and load all configured tags. |
| `resetTag` | N/A | Reset the page-structure and all previously configured properties. |
| `setCookieDomain` | 1: string | Set the default cookie domain for all Relay42 cookies (starting with `_sv`) |
| `setDataCookieTtl` | 1: string | Set the default cookie TTL (time to live) for all Relay42 cookies (starting with `_sv`) in days. The default is 730 days. |
| `setDebug` | N/A | Function to set a debug message for a tag that’s not executed due to a selection rule or journey rule |
| `addInitCallback` | 1: `propertyObject` (object) | Functions to pass settings |

## Additional functions (data tracking)

| Function | Arguments | Description |
| --- | --- | --- |
| `setEngagement` | 1: true/false (boolean) | When an engagement has been set (true), the engagement and all its additional data will be triggered by a 'trackPageView' or 'trackInPageEvent'. |
| `setEngagementType` | 1: name (string) | The engagement type is defined in the 'configuration' tab |
| `setEngagementContent` | 1: content (any) | Add content to the current engagement. |
| `addCustomProperty` | 1: name (string), 2: value (any) | Add a property to the engagement. |
| `resetEventSettings` | - | - |
| `trackInPageEvent` | - | - |
| `setConversion` | 1: true (boolean) | When a conversion has been set (true), the conversion and all its additional data will be triggered by a 'trackPageView' or 'trackInPageEvent'. |
| `setTransactionId` | 1: transactionId (string) | To identify unique conversions |
| `setConversionValue` | 1: value (double) | Keep track of the value of conversions |
| `addConversionProduct` | 1: product identifier (string) | Keep track of number of products |
| `setSharedPermissionKey` | 1: key identifier (string) | The key under which shared permission is saved to the server. This can be used while using cross-domain. Please refer to support for further information |

## Examples

### setEnvironment

Select the environment to use in tag-loading, defaults to “prod”.

```javascript
_st('setEnvironment', 'test');
```

### setPageStructure

Identify the current page, components are used to form a tree structure.

```javascript
_st('setPageStructure', 'default|structure');
```

You can also use the following format:

```javascript
st('setPageStructure', 'default', 'structure');
```

### setDefaultPageStructure

Identify the fallback structure for the current page, components are used to form a tree structure.

```javascript
_st('setDefaultPageStructure', 'default|structure');
```

### setStructurePrefix

Set a prefix for the pagestructure which prepended to the configured structure.

```javascript
_st('setStructurePrefix', 'special');
```

### addTagProperty

Add a property to the current tag-set, the property will be forwarded to the remote system.

```javascript
_st('addTagProperty', 'example', 'property');
```

### addLocalTagProperty

Add a property to the current tag-set, the property will be kept locally in the browser.

```javascript
_st('addTagProperty', 'exampleLocal', 'property');
```

### addTagProperties

Add all object fields as properties to the current tag-set; the properties will be forwarded to the remote system.

```javascript
_st('addTagProperties',  {'example': 'property', 'otherExample': property});
```

### addLocalTagProperties

Add all object fields as properties to the current tag-set; the properties will be kept locally in the browser.

```javascript
_st('addLocalTagProperties',  {'exampleLocal': 'property', 'otherLocalExample': property});
```

### resetTags

Reset the page-structure and all previously configured properties.

```javascript
_st('resetTags');
```

### addLocalTagProperties

Add all object fields as properties to the current tag-set; the properties will be kept locally in the browser.

```javascript
_st('addTagProperty', 'example', 'property');
```

### loadTags

Activate the loading of the tags based on the settings added at this moment.

```javascript
_st('loadTags');
```

### loadTags (shorthand 1)

The same as the normal `loadTags` but with adding the page structure directly to the call.

```javascript
_st('loadTags', 'homepage', 'product');
```

### loadTags (shorthand 2)

The same as the normal `loadTags` but with adding the page structure and a set of normal `tagProperties` directly to the call.

```javascript
_st('loadTags', 'homepage|product|details', {country:'be', language:'nl'});
```