# Update functions
<a name="update-function"></a>

You can update a function at any time. The changes are made only to the version of the function that is in the `DEVELOPMENT` stage. To copy the updates from the `DEVELOPMENT` stage to `LIVE`, you must [publish the function](publish-function.md). 

You can update a function's code in the CloudFront console or with the AWS Command Line Interface (AWS CLI).

------
#### [ Console ]

**To update function code**

1. Sign in to the CloudFront console at [https://console.aws.amazon.com/cloudfront/v4/home#/functions](https://console.aws.amazon.com/cloudfront/v4/home#/functions) and choose the **Functions** page.

   Choose the function to update.

1. Choose **Edit** and make the following changes:
   + Update any fields in the **Details** section.
   + Change or remove the associated key value store. For more information about key value stores, see [Amazon CloudFront KeyValueStore](kvs-with-functions.md).
   + Change the function code. Choose the **Build** tab, make changes, then choose **Save changes** to save changes to the code.

------
#### [ CLI ]

**To update the function code**

1. Open a command line window.

1. Run the following command.

   This example uses the `fileb://` notation to pass in the file. It also includes line breaks to make the command more readable. 

   ```
   aws cloudfront update-function \
       --name MaxAge \
       --function-config '{"Comment":"Max Age 2 years","Runtime":"cloudfront-js-2.0","KeyValueStoreAssociations":{"Quantity":1,"Items":[{"KeyValueStoreARN":"arn:aws:cloudfront::111122223333:key-value-store/a1b2c3d4-5678-90ab-cdef-EXAMPLE11111"}]}}' \
       --function-code fileb://function-max-age-v1.js \
       --if-match ETVABCEXAMPLE
   ```
**Notes**  
You can identify the function by both its name and ETag (in the `if-match` parameter). Make sure that you use the current ETag. You can get this value from the [DescribeFunction](https://docs.aws.amazon.com/cloudfront/latest/APIReference/API_DescribeFunction.html) API operation.
You must include the `function-code`, even if you don't want to change it.
Be careful with the `function-config`. You should pass everything that you want to keep in the configuration. Specifically, handle the key value store as follows:   
To retain the existing key value store association (if there is one), specify the name of the *existing *store.
To change the association, specify the name of the *new *key value store.
To remove the association, omit the `KeyValueStoreAssociations` parameter. 

   When the command is successful, you see output like the following. 

   ```
   ETag: ETVXYZEXAMPLE
   FunctionSummary:
     FunctionConfig:
       Comment: Max Age 2 years \
       Runtime: cloudfront-js-2.0 \
       KeyValueStoreAssociations= \
         {Quantity=1, \
         Items=[{KeyValueStoreARN='arn:aws:cloudfront::111122223333:key-value-store/a1b2c3d4-5678-90ab-cdef-EXAMPLE11111'}]} \
     FunctionMetadata: \
       CreatedTime: '2021-04-18T20:38:56.915000+00:00' \
       FunctionARN: arn:aws:cloudfront::111122223333:function/MaxAge \
       LastModifiedTime: '2023-12-19T23:41:15.389000+00:00' \
       Stage: DEVELOPMENT \
     Name: MaxAge \
     Status: UNPUBLISHED
   ```

------

Most of the information is repeated from the request. Other information is added by CloudFront.

**Notes**  
`ETag` – This value changes each time you modify the key value store.
`FunctionARN` – The ARN for your CloudFront function.
`Stage` – The stage for the function (`LIVE` or `DEVELOPMENT`). 
`Status` – The status of the function (`PUBLISHED` or `UNPUBLISHED`).