# Design Decisions
## No Join or Leave Lifecycle
The receiver crate needs explicit group membership management. The sender side
does not, so `mctx-core` collapses that complexity into immediate-ready
publications.
## Connected UDP Sockets
Each publication connects its UDP socket to a single multicast destination.
That keeps repeated sends simple and avoids rebuilding the same destination
address on every call.
## Optional Add-Ons
The base crate keeps only the essentials:
- `socket2`
- `thiserror`
Async support and metrics are gated behind features so lightweight embeddings do
not pay for them by default.