§3 says an unknown subagent key fails at publish, not at run time, and
refuseSubagentCycle enforced that in one direction only: the edge was
checked when the PARENT was written, and nothing re-checked it when the
CHILD was later archived. So a spec could validate on Monday and be
delegating into nothing by Friday.
That is what happened on 2026-09-15. activity-agent was archived while
krow-workforce-agent v2 still listed it, and every run since logged
runtime.unknown_subagent and answered activity questions without its
activity capability -- quietly, because the parent still Completed.
Both archive paths now refuse with 409 naming the dependents: the
status-only patch the UI sends, and a markdown save whose frontmatter
says archived. Only PUBLISHED parents count, so an abandoned draft
cannot pin a production agent in place. Unlike the cycle check this
fails closed when the graph cannot be read, because the only backstop
here is the failure it exists to prevent.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PJvibeSc1JYXjatankqM1g
Suriya
b765495eb7