The engine and the worker speak a version-matched protocol, but compose.dev.yml mounted only backend/fluksio: a reloaded engine talked to the worker baked into the image. Adding the request id to that protocol therefore left every python node failing with "the worker answered request None", because the old worker echoed no id at all. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01StpRc2C6au1WJ1EUU7fsfu