nix/doc/manual/rl-next/http-binary-cache-compression.md

synopsis	prs
HTTP binary caches now support transparent compression for metadata

HTTP binary cache stores can now compress .narinfo, .ls, and build log files before uploading them, reducing bandwidth usage and storage requirements. The compression is applied transparently using the Content-Encoding header, allowing compatible clients to automatically decompress the files.

Three new configuration options control this behavior:

• narinfo-compression: Compression method for .narinfo files
• ls-compression: Compression method for .ls files
• log-compression: Compression method for build logs in log/ directory

Example usage:

nix copy --to 'http://cache.example.com?narinfo-compression=gzip&ls-compression=gzip' /nix/store/...
nix store copy-log --to 'http://cache.example.com?log-compression=br' /nix/store/...