One request and whatever became of it.
id: number
What this request is called for the rest of the session: #3, and .request #3 afterwards.
Counts up and never repeats, so a number keeps meaning the same request however many more are
made — which a position counted from the end cannot. 0 until a store has kept it:
remember is what names one.
failed: string | null
Why there is no reply, said the way it would be said out loud. null where there is one.
ms: number
Wall-clock milliseconds, rounded — a REPL has no use for the fractions.
at: number
When it was made, for ordering and for saying how long ago.