---
title: Override a Set-Cookie header with a certain value
description: Get a specific `Set-Cookie` header and update it with a certain value.
image: https://edgetunnel-b2h.pages.dev/core-services-preview.png
---

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# Override a Set-Cookie header with a certain value

Get a specific `Set-Cookie` header and update it with a certain value.

**JavaScript**

```js
export default {
  async fetch(request) {
    // Receive response from the origin
    const response = await fetch(request);


    // Create a new Headers object to modify response headers
    const newHeaders = new Headers(response.headers);


    // Get all Set-Cookie headers
    const cookieArray = response.headers.getSetCookie();
    if (cookieArray.length > 0) {
      const updatedCookies = cookieArray.map((cookie) => {
        // For example, replace the currency value with GBP
        if (cookie.trim().startsWith("currency=")) {
          return cookie.replace(/currency=[^;]+/, "currency=GBP");
        }
        return cookie;
      });


      // Delete the existing Set-Cookie headers
      newHeaders.delete("Set-Cookie");


      // Add the updated Set-Cookie headers individually
      updatedCookies.forEach((cookie) => {
        newHeaders.append("Set-Cookie", cookie.trim());
      });
    }


    // Return the modified response with updated headers
    return new Response(response.body, {
      status: response.status,
      headers: newHeaders,
    });
  },
};
```

```json
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```