AWS Documentation » Amazon CloudFront » Developer Guide » Customizing Content at the Edge with Lambda@Edge » Writing and Creating a Lambda@Edge Function » Writing Functions for Lambda@Edge

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Writing Functions for Lambda@Edge

There are several resources to help you with writing Lambda@Edge functions:

• For more information about writing Lambda functions that you can use with Lambda@Edge, see Requirements and Restrictions on Lambda Functions.

• To learn about the event structure to use with Lambda@Edge functions, see Lambda@Edge Event Structure.

• To see examples of Lambda@Edge functions, such as functions for A/B testing and generating an HTTP redirect, see Lambda@Edge Example Functions.

The programming model for using Node.js or Python with Lambda@Edge is the same as using Lambda in an AWS Region. For more information, see Building Lambda Functions with Node.js or Building Lambda Functions with Python.

In your Lambda@Edge code, include the callback parameter and return the applicable object for request or response events:

• Request events – Include the cf.request object in the response.

  If you're generating a response, include the cf.response object in the response. For more information, see Generating HTTP Responses in Request Triggers.

• Response events – Include the cf.response object in the response.