Knip — Dead Code & Dependency Cleanup

Knip finds unused files, dependencies, exports, types, and duplicate packages in JavaScript/TypeScript projects. Use this skill to analyze, report, and safely clean up projects.

What Knip Detects

Installation

# Install as dev dependency (recommended)
pnpm add -D knip

# Or run without installing
pnpm dlx knip

Configuration

Knip works zero-config for many projects but supports knip.json, knip.jsonc, .knip.json, knip.ts, or a knip key in package.json.

Basic Config (knip.json)

{
  "$schema": "https://unpkg.com/knip@latest/schema.json",
  "entry": ["src/index.ts", "src/main.ts"],
  "project": ["src/**/*.ts"],
  "ignore": ["**/*.test.ts", "**/*.spec.ts"],
  "ignoreDependencies": ["@types/node"]
}

Monorepo Config

{
  "$schema": "https://unpkg.com/knip@latest/schema.json",
  "workspaces": {
    "packages/*": {
      "entry": ["src/index.ts"],
      "project": ["src/**/*.ts"]
    },
    "apps/web": {
      "entry": ["src/main.tsx", "next.config.{js,ts}"],
      "project": ["src/**/*.{ts,tsx}"]
    }
  }
}

Common Framework Configurations

Next.js:

{
  "entry": [
    "src/app/**/page.tsx",
    "src/app/**/layout.tsx",
    "src/app/**/route.ts",
    "src/app/**/loading.tsx",
    "src/app/**/error.tsx",
    "src/app/**/not-found.tsx",
    "src/middleware.ts",
    "next.config.{js,ts,mjs}"
  ],
  "project": ["src/**/*.{ts,tsx}"]
}

Vite/React:

{
  "entry": ["src/main.tsx", "vite.config.ts"],
  "project": ["src/**/*.{ts,tsx}"]
}

Express/Node API:

{
  "entry": ["src/index.ts", "src/server.ts"],
  "project": ["src/**/*.ts"],
  "ignoreDependencies": ["@types/express"]
}

Built-in Plugin Support

Knip has built-in plugins for common tools and frameworks. These automatically detect entry points so you don't need to configure them manually:

• Frameworks: Next.js, Remix, Astro, Nuxt, Svelte, Angular, Gatsby
• Build tools: Vite, Webpack, Rollup, esbuild, tsup, Turbopack
• Testing: Jest, Vitest, Mocha, Playwright, Cypress, Storybook
• Linting: ESLint, Prettier, Stylelint, lint-staged, commitlint
• Bundlers/Config: TypeScript, Babel, PostCSS, Tailwind CSS
• CI/CD: GitHub Actions, Husky, Lefthook
• Other: Prisma, Drizzle, GraphQL Codegen, Sentry, MSW

When a plugin detects its config file, it automatically adds the right entry points. Override or extend with explicit config only when needed.

Running Knip

Basic Commands

# Full scan — all issue types
pnpm knip

# Specific reporters
pnpm knip --reporter compact    # Condensed output
pnpm knip --reporter json       # Machine-readable JSON
pnpm knip --reporter markdown   # Markdown table format

# Filter by issue type
pnpm knip --include files           # Only unused files
pnpm knip --include dependencies    # Only unused deps
pnpm knip --include exports         # Only unused exports
pnpm knip --include types           # Only unused types
pnpm knip --include duplicates      # Only duplicate packages
pnpm knip --include unlisted        # Only unlisted deps

# Exclude issue types
pnpm knip --exclude exports    # Everything except unused exports

# Production mode (skip devDependencies analysis)
pnpm knip --production

# Strict mode (also flag re-exports and namespace imports as unused)
pnpm knip --strict

# Show which plugins are activated
pnpm knip --debug

# Performance profiling
pnpm knip --performance

Auto-Fix Mode

# Remove unused exports and dependencies automatically
pnpm knip --fix

# Preview what --fix would change (dry run)
pnpm knip --fix --dry-run

# Only fix specific categories
pnpm knip --fix --include exports
pnpm knip --fix --include dependencies

# Remove unused files (moves to trash by default if trash-cli is installed)
pnpm knip --fix --allow-remove-files

Important --fix behavior:

• Removes unused export keywords from declarations
• Removes unused dependency entries from package.json
• Does NOT delete files unless --allow-remove-files is passed
• Does NOT run your package manager's install after removing deps — you must run pnpm install after
• Always review changes with git diff after running --fix

Safe Removal Workflow

Follow this order when cleaning up knip findings to avoid cascading false positives:

Step 1: Fix Unlisted Dependencies First

pnpm knip --include unlisted
# Add any missing packages to package.json
pnpm add <missing-package>

Step 2: Remove Unused Dependencies

pnpm knip --include dependencies --fix
pnpm install   # Regenerate lockfile

Step 3: Remove Unused Exports

# Preview first
pnpm knip --include exports --fix --dry-run
# Then apply
pnpm knip --include exports --fix

Step 4: Remove Unused Files

# List unused files
pnpm knip --include files
# Review each file manually before deletion
# Only use --allow-remove-files when confident

Step 5: Verify Nothing Broke

pnpm tsc --noEmit       # Type check
pnpm test               # Run tests
pnpm build              # Verify build
pnpm knip               # Re-run to confirm clean

Handling False Positives

Knip may flag things as unused that are actually needed:

Dynamic imports / runtime usage

{
  "ignoreDependencies": ["sharp", "pg-native"]
}

Exports consumed by external packages (library authors)

{
  "entry": ["src/index.ts!"],
  "ignore": ["src/internal/**"]
}

The ! suffix means "include all exports from this entry as used."

Framework magic (decorators, auto-imports, etc.)

Use the appropriate plugin or add explicit entry points.

Per-file export ignore

/** @public */
export function myPublicAPI() {} // knip respects JSDoc @public tag

Or use the @knip tag in comments:

// @knip — used by external consumers
export const API_VERSION = "2.0";

Ignore patterns

{
  "ignore": [
    "**/*.d.ts",
    "**/generated/**",
    "scripts/**"
  ],
  "ignoreDependencies": [
    "@types/*",
    "dotenv"
  ]
}

Interpreting Results

When presenting knip results:

1. Group by severity — unlisted deps and unresolved imports are critical; unused types are informational
2. Check before removing exports — they may be part of a public API consumed by other packages
3. Cross-reference unused deps — check if they're used in scripts, CI configs, or Dockerfiles that knip doesn't scan
4. Unused files — verify they aren't dynamically imported, used as templates, or referenced in config files
5. Duplicate packages — these bloat bundles; resolve by aligning versions in package.json or using pnpm dedupe

Integration with Quality Gate

Knip is included in the quality gate as a WARN-level check. For standalone deep analysis, use the /knip command instead, which provides more granular control and guided cleanup workflows.