> For the complete documentation index, see [llms.txt](https://docs.chainvine.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.chainvine.xyz/developers/use-cases/leverage-cookies.md).

# Leverage cookies

> Note: these operations rely on browser functionality and will throw an error if used in a non-browser context

### Storing a Referrer

```typescript
import { storeReferrer } from '@chainvine/sdk';

// Fetches the "r" query parameter from the URL (if available)
// and stores it in a CV_REF cookie with an expiration of 120 days
storeReferrer();
```

Should you already have a reference to he referrer's ID or if you would like to adjust the cookies expiration you may do so by providing overrides as below:

```typescript
storeReferrer({
  durationDays: 30, //Override the default cookie duration (120 days)
  referrer: 'ABC123', //Should you already have access to the referrer, and if you do not want it fetched from the URL, you can provide it directly
}); 
```

### Fetching a stored Referrer

Once you've stored the referrer, you can access it at any point in your application like so:

```typescript
import { getReferrer } from '@chainvine/sdk';

const referrer = getReferrer();
```

### Clearing the stored Referrer

The referrer cookie can be cleared at any point using the following operation:

```typescript
import { clearReferrer } from '@chainvine/sdk';

clearReferrer();
```


---

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