quickstart.mdx

title	Quick start
description	Run Fallow for the first time and understand the output in under a minute. One golden path, then branch into VS Code, CI, MCP, or runtime intelligence.
keywords	quickstart fallow typescript javascript dead code duplication complexity npx fallow
icon	rocket

This page gets you from zero to a useful result fast. Everyone starts the same way. Branch off at the end.

1. Run Fallow

From your project root:

npx fallow

That runs three analyses in one pass:

• Dead code: unused files, exports, dependencies, cycles, boundaries, and more
• Duplication: repeated logic across files
• Health: complexity hotspots and refactor targets

95 built-in plugins cover Next.js, Vite, Jest, Tailwind, PandaCSS, tap, tsd, and more. No configuration needed for the first run.

2. Run the focused commands you'll use most

npx fallow dead-code          # Cleanup candidates
npx fallow dupes              # Repeated logic
npx fallow health             # Complexity and refactor targets
npx fallow fix --dry-run      # Preview automatic cleanup

3. Understand the output

Dead code

Use this when you want cleanup candidates.

npx fallow dead-code

Reports unused files, exports, types, dependencies, circular deps, and boundary violations. See the dead code guide.

Duplication

Use this when repeated logic is spreading.

npx fallow dupes

Default mild mode catches AST-based duplicates. Add --mode semantic to also catch clones with renamed variables. See the duplication guide.

Health

Use this when you want to prioritize refactors.

npx fallow health

Reports complexity findings, per-file maintainability, hotspots, and ranked refactor targets. See the health explanation.

Fix preview

Use this before deleting anything automatically.

npx fallow fix --dry-run

When you're ready, drop --dry-run. See the auto-fix guide.

4. Pick your next step

Existing repo with backlog? Read [Adopt Fallow in an existing repo](/adoption) for a structured cleanup path, then come back here to wire up CI or VS Code. Real-time diagnostics, Code Lens above exports, and one-click fixes. Turn Fallow into a PR and merge gate with SARIF or MR annotations. Add MCP for structured tool calling from Claude Code, Cursor, and more. Layer production execution data into `fallow health`.

Optional: create a config

Fallow works without a config file. When you want to customize, run:

fallow init

This auto-detects your project structure and generates a tailored config. It also adds .fallow/ to your .gitignore.

```jsonc .fallowrc.json { "$schema": "https://raw.githubusercontent.com/fallow-rs/fallow/main/schema.json", "entry": ["src/workers/*.ts", "scripts/*.ts"], "ignorePatterns": ["**/*.generated.ts"], "rules": { "unused-files": "error", "unused-exports": "warn", "unused-types": "off" } } ``` ```toml fallow.toml entry = ["src/workers/*.ts", "scripts/*.ts"] ignorePatterns = ["**/*.generated.ts"]

[rules] unused-files = "error" unused-exports = "warn" unused-types = "off"

</CodeGroup>

<Info>
  Migrating from knip or jscpd? Run `fallow migrate`, or see the [knip](/migration/from-knip) or [jscpd](/migration/from-jscpd) guides.
</Info>

## Optional: runtime intelligence

Fallow's static layer is free and open source. If you want to know what actually executed in production, add the runtime layer:

```bash
npx fallow license activate --trial --email you@company.com
npx fallow coverage setup
npx fallow health --runtime-coverage ./coverage

Before you do that, read Static vs runtime intelligence for the mental model, then the runtime coverage guide for setup details.

Optional: workflow-specific setup

Agents

Any agent that can run a shell command can use Fallow. Use --format json for structured output:

npx fallow --format json
npx fallow dead-code --format json
npx fallow fix --dry-run --format json

If your agent supports MCP, add structured tool calling:

{
  "mcpServers": {
    "fallow": {
      "command": "fallow-mcp"
    }
  }
}

See the MCP integration guide.

Humans

Install the VS Code extension for real-time diagnostics, Code Lens above exports, and one-click fixes:

code --install-extension fallow-rs.fallow-vscode

See the VS Code integration guide.

CI

Use the GitHub Action, the GitLab template, or npx fallow --ci on any CI:

```yaml - uses: fallow-rs/fallow@v2 with: format: sarif ``` ```yaml include: - remote: 'https://raw.githubusercontent.com/fallow-rs/fallow/main/ci/gitlab-ci.yml'

fallow:
  extends: .fallow
```

```yaml - run: npx fallow --ci ```

See the CI integration guide.

Next steps

What Fallow analyzes, at a glance. Customize entry points, rules, and ignore patterns. Mental models for how Fallow works. Every command and flag.