Shared-memory data streaming for colocated Solana services. Fans account/transaction updates from one sender to local consumers over per-consumer SPSC rings in /dev/shm, with a Unix-domain control socket for handshake, subscriptions, and eventfd wakeups. Zero-copy hot path, sender-side filtering (bloom-pre-reject for large filters), backpressure-aware consumer drops, and opportunistic LZ4. Rust, Linux-only (eventfd, memfd_create, SCM_RIGHTS). By Brew Labs.