fallow

Agent skills for the JavaScript and TypeScript codebase intelligence layer.

Agent skills for fallow, Rust-native codebase intelligence for JavaScript and TypeScript. The free static layer finds unused code, circular dependencies, code duplication, complexity hotspots, and architecture boundary violations in milliseconds. The optional paid runtime layer (Fallow Runtime) adds production execution evidence so agents can delete cold code, flag hot-path changes, and retire stale flags with proof. 90 framework plugins, zero configuration. Works with any agent that supports the Agent Skills specification: Claude Code, Cursor, OpenAI Codex, Windsurf, GitHub Copilot, Gemini CLI, Amp, and 30+ more.

Linters enforce style. Formatters enforce consistency. Fallow enforces relevance. Linters work file by file. TypeScript works type by type. Neither builds the full module graph, so neither can see what nothing depends on. Fallow does, in milliseconds. These skills teach agents how to use fallow effectively: which commands to run, what flags to use, how to interpret output, and how to avoid common pitfalls.

Quick Start

Claude Code

/install fallow-rs/fallow-skills

Cursor

git clone https://github.com/fallow-rs/fallow-skills.git ~/.cursor/skills/fallow-skills

OpenAI Codex

git clone https://github.com/fallow-rs/fallow-skills.git ~/.agents/skills/fallow-skills

Windsurf

git clone https://github.com/fallow-rs/fallow-skills.git ~/.codeium/windsurf/skills/fallow-skills

GitHub Copilot

git clone https://github.com/fallow-rs/fallow-skills.git .github/skills/fallow-skills

Gemini CLI

gemini skills install https://github.com/fallow-rs/fallow-skills.git

Amp

git clone https://github.com/fallow-rs/fallow-skills.git ~/.config/agents/skills/fallow-skills

Other agents

Clone or copy the skill directory into your agent's skills location. This skill follows the open Agent Skills specification and works with any compatible agent.

Prerequisites

Fallow must be installed in the target project:

npm install -g fallow    # prebuilt binaries
npx fallow dead-code         # or run without installing

See the installation guide for all options including cargo install fallow-cli.

Available Skills

Skill	Description	Trigger phrases
fallow	Codebase intelligence for JS/TS: unused code, circular deps, duplication, complexity, and (with Runtime) hot-path and cold-path evidence	"find dead code", "unused exports", "find duplicates", "check code health", "what code actually runs"

What's Included

fallow

Category	What it does
Dead Code	Find unused files, exports, types, dependencies, enum/class members (15 issue types)
Duplication	Find code clones with 4 modes: strict, mild, weak, semantic
Complexity	Function complexity analysis, hotspot detection, health scores
Auto-Fix	Remove unused exports and dependencies with dry-run preview
CI	GitHub Actions, SARIF upload, baseline comparison, PR-scoped checks
Monorepo	Per-workspace analysis with cross-package resolution
Debug	Trace export usage chains, file edges, and dependency usage

Reference Documentation

• CLI Reference: all 10 commands, flags, JSON output structure, config format
• Gotchas: 19 pitfalls with WRONG/CORRECT examples
• Patterns: 14 workflow recipes for CI, monorepos, migration, incremental adoption

Example Prompts

Once installed, you can use natural language:

• "Find all dead code in this project"
• "Are there any unused dependencies?"
• "Find code duplication in the codebase"
• "Clean up unused exports"
• "Set up a CI check for dead code"
• "Check the complexity of this codebase"
• "Why is this export flagged as unused?"
• "Check if this PR introduces dead code"
• "Find unused files in the payments package"
• "What's the duplication percentage?"

How It Works

User: "Find all unused exports"
  ↓
Agent loads fallow skill
  ↓
Skill instructs: run `fallow dead-code --format json --quiet --unused-exports`
  ↓
Agent executes command, parses JSON output
  ↓
Agent summarizes findings with file paths and line numbers

The skill provides agents with:

1. Command knowledge: which fallow command + flags to use for each task
2. Output parsing: how to interpret JSON results
3. Guardrails: always dry-run before fix, never run watch, use --yes in non-TTY
4. Debugging: how to trace false positives with --trace

Contributing

See CLAUDE.md for repository structure, skill creation guidelines, and quality standards.

Related

• fallow: Rust-native codebase intelligence for JavaScript and TypeScript (3-36x faster than knip)
• fallow-docs: Official documentation
• VS Code extension: Real-time diagnostics in your editor
• Agent Skills specification: The open standard this skill follows

License

MIT. See LICENSE for details.