Amazon CloudFront
Developer Guide (API Version 2016-09-29)

Editing a Lambda Function for Lambda@Edge

When you want to edit a Lambda function, note the following:

  • The original version is labeled $LATEST.

  • You can edit only the $LATEST version.

  • Each time you edit the $LATEST version, you must publish a new numbered version.

  • You can't create triggers for $LATEST.

  • When you publish a new version of a function, Lambda doesn't automatically copy triggers from the previous version to the new version. You must reproduce the triggers for the new version.

  • When you add a trigger for a CloudFront event to a function, if there's already a trigger for the same distribution, cache behavior, and event for an earlier version of the same function, Lambda deletes the trigger from the earlier version.

  • After you make updates to a CloudFront distribution, like adding triggers, you must wait for the changes to propagate to edge locations before the functions you've specified in the triggers will work.

To edit a Lambda function (AWS Lambda console)

  1. Sign in to the AWS Management Console and open the AWS Lambda console at

  2. In the region list at the top of the page, choose US East (N. Virginia).

  3. In the list of functions, choose the name of the function that you want to edit.

    By default, the console displays the $LATEST version. You can view earlier versions (choose Qualifiers), but you can only edit $LATEST.

  4. On the Code tab, for Code entry type, choose to edit the code in the browser, upload a .zip file, or upload a file from Amazon S3.

  5. Choose either Save or Save and test.

  6. Choose Actions, and choose Publish new version.

  7. In the Publish new version from $LATEST dialog box, enter a description of the new version. This description appears in the list of versions, along with an automatically generated version number.

  8. Choose Publish.

    The new version automatically becomes the latest version. The version number appears on the Version button in the upper-left corner of the page.

  9. Choose the Triggers tab.

  10. Choose Add trigger.

  11. In the Add trigger dialog box, choose the dotted box, and then choose CloudFront.


    If you've already created one or more triggers for a function, CloudFront is the default service.

  12. Specify the following values to indicate when you want the Lambda function to execute.

    Distribution ID

    Choose the ID of the distribution that you want to add the trigger to.

    Cache behavior

    Choose the cache behavior that specifies the objects that you want to execute the function on.

    CloudFront event

    Choose the CloudFront event that causes the function to execute.

    Enable trigger and replicate

    Select this check box so Lambda replicates the function to regions globally.

  13. Choose Submit.

  14. To add more triggers for this function, repeat steps 10 through 13.