Sounds like Magic Wormhole (https://magic-wormhole.io/). The readme acknowledges Warner at the end.

Key differences seem to be resumable transfers and proxy support.

Another is a single binary, whereas MW is in Python, but there’s now https://github.com/magic-wormhole/magic-wormhole.rs

I appreciate that the project acknowledges its inspiration. I wish it were more common for projects to provide detailed comparisons with similar ones for people trying to choose.