Fallow Cleans AI-Shipped JS/TS Slop in Seconds
Fallow detects dead code, duplicates, and complexity in JS/TS projects with zero config, auto-detects 90+ frameworks, and outputs line-level JSON for AI agents like Claude to fix issues without breaking functionality.
Zero-Config Analysis Replaces Tool Soup
Fallow runs as a single bunx fallow summary command on JS/TS codebases, instantly generating reports on dead code, duplication, complexity health, and architectural boundaries without installation or config. It auto-detects frameworks via 90+ plugins, caches results in a .fallow directory for faster reruns, and computes a maintainability index from cyclomatic/cognitive complexity density—scoring files below threshold (e.g., 41 files needing refactor in a Claude-built project). Use fallow dups for line-specific duplicates (e.g., exact files/lines), fallow health for CRAP (Change Risk Anti-Patterns) scores per file, or fallow dead for unused exports. Dry-run fallow fix --dry-run previews auto-removals like unused exports, but skip auto-fix due to lacking semantic context. Custom .fallowrc ignores patterns (e.g., tests), tunes duplication thresholds, or enforces boundaries (e.g., directories that can't import others). Export JSON (--format json) for machine parsing.
AI Agent Skills Turn Reports into Fixes
Install Fallow's Claude skill for guardrails/prompts, then prompt Claude: "Study project, run fallow dups --format json, fix duplicates without breaking core functionality, create feature branch, run tests." Claude analyzes, ignores test dupes, fixes 3 files (adds 54 lines including .fallowrc to exclude tests, removes 43), and opens a PR—all in ~4 minutes. VS Code plugin or MCP server enable similar hooks for Cursor/other agents. Sequential fixes handle health/dead code next, ensuring tests pass.
CI/PR Enforcement and Runtime Coverage
fallow audit diffs PRs against main (or --base other-branch), flagging only new issues. fallow setup hooks generates Claude prompts for PRs. GitHub Actions add PR annotations, support monorepos/workspaces, export health badges/SVGs, and baselines (fix legacy issues gradually, block only regressions). Pre-commit hooks enforce on changes. Paid runtime intelligence merges V8 coverage from production traffic via sidecar (local/deployable), revealing truly dead code beyond static analysis. Built on Oxc (Evan You-funded) for parsing/module resolution before graph analysis.