> Fetch clean Markdown by appending `.md` to any page URL under https://signalwire.com/docs or requesting it with the HTTP header `Accept: text/markdown`. The root index at https://signalwire.com/docs/llms.txt lists the available documentation indexes.

# enableEnvExpansion

> Enable or disable environment variable expansion in URLs, bodies, and outputs.

[ref-datamap]: /docs/server-sdks/reference/typescript/agents/data-map

Enable `${ENV.*}` variable expansion in URLs, bodies, and outputs.

## **Parameters**

**`enabled`** `boolean` — default: true

Whether to enable expansion. Defaults to `true` if omitted.

---

## **Returns**

[`DataMap`][ref-datamap] -- Self for method chaining.

## **Example**

```typescript {4}
import { DataMap } from '@signalwire/sdk';

const dm = new DataMap('get_weather');
dm.enableEnvExpansion();
dm.setAllowedEnvPrefixes(['WEATHER_']);
dm.webhook('GET', 'https://api.weather.com/v1/current?key=${ENV.WEATHER_API_KEY}');
```

> Enable or disable environment variable expansion in URLs, bodies, and outputs.