What gives a model away?

Shibbo tracks the habits that mark a model’s work as machine-made, in four layers: prose, interface, code and behavior. It keeps a dated, sourced registry of these tells and maps which models show which ones, release by release.

Your agent can drop them. Set shibbo up in a coding agent and it gives the rules before work starts, then checks each edit and the final reply. The checker also runs from the command line (npx shibbo check draft.md), as an MCP server, and inside Claude Code, Codex, Cursor, Copilot, Gemini CLI and other agent harnesses.

Browse the tells, compare models, read the docs, or get the code on GitHub.