Struct CallSpec 

pub struct CallSpec<'a> {
    pub target: &'a CallTarget,
    pub producer: &'a str,
    pub procedure: &'a str,
    pub params: &'a [String],
    pub body: Option<Vec<u8>>,
    pub attachment: Option<Vec<u8>>,
    pub timeout: Duration,
    pub slices: Option<&'a SliceSet>,
}

One procedure call, as a spec rather than nine positional arguments — the shape crate::BenchSpec already uses next door, for the same call.

body and attachment are owned because they are consumed: they ride the GET out and nothing reads them again.

Fields

target: &'a CallTarget

producer: &'a str

procedure: &'a str

Slash-separated, as the registry spells it (capture/trigger).

params: &'a [String]

Selector parameters, joined with ; onto the key (RFC 05 §1).

body: Option<Vec<u8>>

The request payload, already through the encode ladder.

attachment: Option<Vec<u8>>

Verbatim, never schema-encoded — an attachment is outside the registry’s vocabulary (#117).

timeout: Duration

slices: Option<&'a SliceSet>

The loaded registry, for the fan-out guard below. None = none loaded, and the guard says so rather than judging.