The hello carries the fluksio-worker version. An agent refused for an older protocol stays listed as Needs upgrade until it attaches again. Docs gain an Upgrading workers section. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01WgBfkm4rCmtd1T4vHWjEPx