Federation - forward headers to subgraphs

I’m using the node server along with IntrospectAndCompose to power my federation. Not that it matters, but I’m using postgraphile for my subgraphs, which allows me to set policy at the database layer. I need JWT tokens to facilitate this.

This leads me to the question - how do I forward headers to subgraphs? Is that a Gateway/Server concern, or can Express help (doesn’t seem so, based on my preliminary research)? I saw that the new Rust Router has a yaml config that allows for header forwarding… something similar for JS?