ReadonlyreasonAn optional machine-readable reason, rendered into the response body alongside the message. DECLARED HERE rather than sniffed structurally at the mapper so the channel is part of the contract a subclass opts into, and so the mapper needs no import of any subclass to render it (see the header for why that import must not exist).
ReadonlystatusThe response status. 4xx/5xx only — see doErrorResponse.
A malformed inventory request: an unknown category, an unparseable cursor, or a cursor whose shape does not match the category it was sent to.
400 rather than a silent restart from the beginning. A cursor that quietly resets would make a sweep re-read rows it had already counted and never reach the end, and an operator watching for two consecutive empty sweeps would wait forever without being told why.