The JSON-Mode Prompt Pattern That Survives Claude Version Bumps

Book: Prompt Engineering Pocket Guide My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub Picture a classification pipeline that has run cleanly for nine months. A new Sonnet release lands, and suddenly a noticeable slice of rows comes back empty. Same prompt, same inputs, same temperature. The diff: the model now likes to preface its JSON with Sure, here's the JSON you asked for: . The downstream regex peels off t