Struct Proposal 

pub struct Proposal<'a> {
    pub id: String,
    pub at: Instant,
    pub actor: &'a dyn Viewer,
    pub command: Value,
}

One client’s proposal, as the merge point sees it.

The reply channel is not here: what a host does with a Decision — a oneshot, a returned frame, a postMessage — is the host’s business, and is the one part of ingress that genuinely differs between a server and a tab.

Fields

id: String

The idempotency key that makes a retry after a reconnect safe (§4.3).

at: Instant

When the merge point admitted it — the one place time enters (§3.7), read by the host from the clock it was configured with and data from here onwards.

actor: &'a dyn Viewer

Who is proposing. A &dyn rather than a type parameter because the two hosts genuinely have different ones: a connection supplies a verified actor with claims, and a test or a tab supplies a name.

command: Value

The command, already decoded against the program’s own Command union.