Optional ReadonlygenerationThe generation ID from the JoinGroup response (v1+). -1 if not in a group.
ReadonlygroupThe consumer group ID.
Optional ReadonlygroupThe group instance ID for static membership (v5+). Null if not static.
Optional ReadonlymemberThe member ID assigned by the group coordinator (v1+).
Optional ReadonlyretentionRetention time in milliseconds (v2–v4, -1 = broker default).
Optional ReadonlytaggedTagged fields (v8+).
ReadonlytopicsPer-topic data.
OffsetCommit request payload.