It seems as though .json_body() would also attempt to decode the body of a proxyevent if the body is marked as base64 encoded. https://github.com/awslabs/aws-lambda-powertools-python/blob/cb0d54bc36513961422fdebd5953bc11453b4651/aws_lambda_powertools/utilities/data_classes/common.py#L68