D035 - The protocol is serialisable data, defined separately from its transport

decided · 2026-08-19

Shim↔︎worker messages are serde types in their own module, with the channel (stdio pipes today) a separate concern. The transport can change without the protocol moving.

Consequence that shapes the service crate: operations must take and return serialisable values rather than handing back rich types holding references into loaded modules. Deciding this before writing the service is the whole point of having decided it.