bytes

The bytes crate provides Bytes and BytesMut — Arc-backed byte buffers that enable zero-copy sharing throughout the tokio ecosystem. Used by hyper, tonic, and every major Rust networking crate.

Why it matters

Passing Bytes between tasks is a reference-count increment, not a copy. BytesMut provides exclusive mutable access that can be frozen into a shared Bytes when writing is done. This is the standard pattern for buffer management in async Rust networking.