A self-hosted relay that shares message threads across Claude Code, Cowork, and Claude.ai so you can hand off state between surfaces without copy-paste. Exposes six tools: list threads, create thread, post message, read thread, check for new messages since last read, and archive thread. Runs as a stateless Cloudflare Worker backed by Supabase Postgres, with static bearer auth for Code and Cowork clients and full OAuth 2.1 with dynamic client registration for Claude.ai custom connectors. Single-tenant by default but the schema is already multi-user ready. Reach for this when you're bouncing between chat, scheduled tasks, and your editor and want a lightweight shared whiteboard that every surface can post to and poll from.