Intuition I was working with an Elasticsearch project on AWS using Python and the requests_aws4auth package worked like a charm for me. Never had any issue regarding the authentication (AWS V4 could be hard to work with sometimes). However, when I trying to create a Shiny app for my project, the problem emerged. I just couldn’t get the V4 auth to work with httr in R. I tried aws.signature package on Github but keep getting request header issues.