The failure this prevents is specific — a sub-agent burns the end of a limit window and the session the
owner is actually sitting in dies mid-turn, because the credits went somewhere nobody was watching. So
it is a condition on spawning rather than a refinement: an endpoint that can start unattended work
without checking is wrong from its first call, and the symptom lands on someone else's conversation.
Wired into POST /command-hq/commanders/new, which — this is the finding — already IS the spawn
mechanism the sub-agents item was asking for. It starts a turn with ws: null, waits only for
session:claude, and returns the transcript id, with command_hq_sessions naming, listing and costing it.
So "commander or something lighter" answers itself: a commander costs nothing extra and a lighter thing
would need its own registry to be visible at all. What is still missing is only the agent-callable
surface.
Refuses rather than queues or downgrades. Queueing means holding work against a window Officer does not
control, and the reset it would wait for is a claim about a shared pool — every claude on the machine
spends these, including terminals and pipelines. A refusal naming the window, the percentage and the
reset is something a caller can act on now.
The floor is 15% and the reasoning is in the file: the interactive failure is not "cannot start a chat",
it is "a turn already in flight is cut off", and a turn costs a fraction of a window.
Fails OPEN, deliberately. The numbers come from an external endpoint with a credential Officer does not
own, so a blip or a signed-out CLI must not stop every spawn on the machine with an error about usage
that has nothing to do with usage. The problem is reported so a caller can say "started, but unchecked".
Seven tests on the pure rule — tightest window decides rather than the average, no limits allowed rather
than blocked, exactly-at-the-ceiling refuses. Verified against the live account, where it correctly
refuses right now at Session 90%.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>