Fallow

Fallow is a codebase health tool for JavaScript and TypeScript that finds unused code, circular dependencies, duplicates, and complexity hotspots with zero configuration. The static analysis is free and fast (sub-second), with 95 framework plugins built in. What makes it interesting is the runtime coverage layer: you can merge production execution data into the same report to see what's actually hot, what's safe to delete, and which feature flags are stale. A single local capture is free, continuous monitoring is paid. The CLI outputs clean JSON for automation, auto-fixes unused exports, and runs in CI with regression baselines. Use it when you need to clean up a codebase before a refactor or want data-driven confidence about what code is actually dead in production.

Install to Claude Code

npx -y skills add fallow-rs/fallow-skills --skill fallow --agent claude-code