There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Add a cache control header to a CloudFront Functions viewer response event
<a name="cloudfront_example_cloudfront_functions_add_cache_control_header_section"></a>

The following code example shows how to add a cache control header to a CloudFront Functions viewer response event.

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#### [ JavaScript ]

**JavaScript runtime 2.0 for CloudFront Functions**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [CloudFront Functions examples](https://github.com/aws-samples/amazon-cloudfront-functions/tree/main/add-cache-control-header) repository. 

```
async function handler(event) {
    var response = event.response;
    var headers = response.headers;
    
    if (response.statusCode >= 200 && response.statusCode < 400) {
        // Set the cache-control header
        headers['cache-control'] = {value: 'public, max-age=63072000'};
    }
        
    // Return response to viewers
    return response;
}
```

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