Claude Mods: Flipping the Harness Inside Out

The author describes Claude Mods, Claude Code plugins written as TypeScript or JavaScript functions that hook into events like prompts, tool calls and interface renders to customize the CLI and Desktop behavior, framing them as an early "Attention Interface" that users can shape themselves. He highlights the built-in You Should Know mod, which flags uncommitted work the agent might cause you to lose, and his own Next Steps Supervisor from the open-source ModSmith plugin, then compares Claude Mods with OpenAI's ChatGPT Intelligent UI and Cursor's PR Routing & Approval. He also notes downsides—noise (99 of 111 turns triggered his supervisor), token cost of roughly 5–6k input-equivalent tokens per check on a 50k-token session, and the fact that mods run unsandboxed with your permissions.