Setup Knip

Setup Knip

Install and configure Knip - the tool for finding unused files, dependencies, and exports in JavaScript/TypeScript projects.

When to Use

• Before running dead-code-hunter agent
• Before running dependency-auditor agent
• When project doesn't have Knip configured
• When upgrading Knip configuration
• In pre-flight validation of health workflows

Instructions

Step 1: Check if Knip is Installed

Check package.json for knip in devDependencies.

Tools Used: Read

# Read package.json and check for knip

Check Logic:

• If devDependencies.knip exists → Knip is installed
• If not found → Need to install

Step 2: Install Knip if Missing

If Knip is not installed, add it as devDependency.

Tools Used: Bash

# Detect package manager
if [ -f "pnpm-lock.yaml" ]; then
  pnpm add -D knip
elif [ -f "yarn.lock" ]; then
  yarn add -D knip
elif [ -f "bun.lockb" ]; then
  bun add -D knip
else
  npm install -D knip
fi

Expected Output:

+ knip@5.x.x

Step 3: Check for Knip Configuration

Look for existing Knip configuration files.

Tools Used: Glob

Configuration Files (in priority order):

1. knip.json
2. knip.jsonc
3. knip.ts
4. knip.config.ts
5. knip.config.js
6. package.json (knip field)

Step 4: Create Default Configuration if Missing

If no configuration found, create knip.json with sensible defaults.

Tools Used: Write

Default Configuration for Standard Project:

{
  "$schema": "https://unpkg.com/knip@5/schema.json",
  "entry": ["src/index.{ts,tsx,js,jsx}", "src/main.{ts,tsx,js,jsx}"],
  "project": ["src/**/*.{ts,tsx,js,jsx}"],
  "ignore": [
    "**/*.d.ts",
    "**/*.test.{ts,tsx}",
    "**/*.spec.{ts,tsx}",
    "**/test/**",
    "**/tests/**",
    "**/__tests__/**",
    "**/node_modules/**"
  ],
  "ignoreDependencies": ["@types/*"]
}

Default Configuration for Next.js Project (detected by next in dependencies):

{
  "$schema": "https://unpkg.com/knip@5/schema.json",
  "entry": [
    "src/app/**/*.{ts,tsx}",
    "src/pages/**/*.{ts,tsx}",
    "app/**/*.{ts,tsx}",
    "pages/**/*.{ts,tsx}"
  ],
  "project": ["src/**/*.{ts,tsx}", "app/**/*.{ts,tsx}", "pages/**/*.{ts,tsx}"],
  "ignore": ["**/*.d.ts", "**/*.test.{ts,tsx}", "**/*.spec.{ts,tsx}", "**/node_modules/**"],
  "next": {
    "entry": ["next.config.{js,ts,mjs}", "middleware.{js,ts}"]
  }
}

Default Configuration for Monorepo (detected by workspaces in package.json):

{
  "$schema": "https://unpkg.com/knip@5/schema.json",
  "workspaces": {
    "packages/*": {
      "entry": ["src/index.{ts,tsx,js,jsx}"],
      "project": ["src/**/*.{ts,tsx,js,jsx}"]
    },
    "apps/*": {
      "entry": ["src/index.{ts,tsx,js,jsx}", "src/main.{ts,tsx,js,jsx}"],
      "project": ["src/**/*.{ts,tsx,js,jsx}"]
    }
  },
  "ignore": ["**/*.d.ts", "**/*.test.{ts,tsx}", "**/*.spec.{ts,tsx}", "**/node_modules/**"]
}

Step 5: Add npm Scripts if Missing

Check if package.json has knip scripts, add if missing.

Tools Used: Read, Bash

Scripts to Add:

{
  "scripts": {
    "knip": "knip",
    "knip:fix": "knip --fix",
    "knip:deps": "knip --dependencies",
    "knip:exports": "knip --exports",
    "knip:files": "knip --files"
  }
}

Add via npm pkg:

npm pkg set scripts.knip="knip"
npm pkg set scripts.knip:fix="knip --fix"
npm pkg set scripts.knip:deps="knip --dependencies"
npm pkg set scripts.knip:exports="knip --exports"
npm pkg set scripts.knip:files="knip --files"

Step 6: Validate Installation

Run Knip to verify installation works.

Tools Used: Bash

npx knip --help

Expected: Help output displayed without errors

Step 7: Return Result

Return structured result indicating setup status.

Expected Output:

{
  "installed": true,
  "version": "5.x.x",
  "config_file": "knip.json",
  "config_created": true,
  "scripts_added": ["knip", "knip:fix", "knip:deps", "knip:exports", "knip:files"],
  "project_type": "nextjs|monorepo|standard",
  "ready": true
}

Error Handling

• Installation fails: Return error with package manager output
• Configuration invalid: Return error with validation details
• Permission denied: Return error suggesting sudo or permission fix
• Network error: Return error suggesting offline installation

Examples

Example 1: Fresh Project (No Knip)

Initial State:

• package.json exists
• No knip in devDependencies
• No knip.json

Actions:

1. Install knip via detected package manager
2. Detect project type (standard)
3. Create knip.json with defaults
4. Add npm scripts
5. Validate installation

Output:

{
  "installed": true,
  "version": "5.73.3",
  "config_file": "knip.json",
  "config_created": true,
  "scripts_added": ["knip", "knip:fix", "knip:deps", "knip:exports", "knip:files"],
  "project_type": "standard",
  "ready": true
}

Example 2: Next.js Project with Existing Knip

Initial State:

• package.json with next dependency
• knip already in devDependencies
• knip.json exists

Actions:

1. Detect knip installed (skip installation)
2. Detect existing config (skip creation)
3. Check scripts (add missing)
4. Validate installation

Output:

{
  "installed": true,
  "version": "5.73.3",
  "config_file": "knip.json",
  "config_created": false,
  "scripts_added": ["knip:deps"],
  "project_type": "nextjs",
  "ready": true
}

Example 3: Monorepo Project

Initial State:

• package.json with workspaces field
• No knip

Actions:

1. Detect monorepo (workspaces in package.json)
2. Install knip
3. Create monorepo-specific knip.json
4. Add npm scripts
5. Validate installation

Output:

{
  "installed": true,
  "version": "5.73.3",
  "config_file": "knip.json",
  "config_created": true,
  "scripts_added": ["knip", "knip:fix", "knip:deps", "knip:exports", "knip:files"],
  "project_type": "monorepo",
  "ready": true
}

Knip Command Reference

For agents using Knip after setup:

CRITICAL SAFETY WARNING

NEVER Use --allow-remove-files

npx knip --fix --allow-remove-files is FORBIDDEN!

Knip has a critical limitation: it cannot detect dynamic imports.

// Knip CANNOT see these relationships:
const module = await import(`./plugins/${name}.ts`);
const Component = lazy(() => import('./components/Dashboard'));
require(`./locales/${lang}.json`);

Files loaded via dynamic imports will appear "unused" to Knip but are actually critical!

Safe Knip Usage

ALLOWED:

• npx knip --fix --fix-type exports - Safe: removes unused exports from files
• npx knip --fix --fix-type types - Safe: removes unused type exports
• npx knip --fix --fix-type dependencies - Safe: removes from package.json only

FORBIDDEN:

• npx knip --fix --allow-remove-files - DANGEROUS: may delete files with dynamic imports
• npx knip --fix (without --fix-type) - May include file removal

Manual Verification Required

Before removing ANY file flagged by Knip:

1. Search for dynamic imports: import(, require(, lazy(, loadable(
2. Check for string interpolation in imports
3. Verify no config files reference the file
4. Run build and tests after removal

Integration with Agents

dead-code-hunter Pre-Check

## Phase 0: Pre-Flight

1. Use setup-knip Skill to ensure Knip is available
2. If result.ready === false, halt with setup instructions
3. If result.ready === true, proceed with detection

dependency-auditor Pre-Check

## Phase 1: Environment Analysis

1. Use setup-knip Skill before dependency analysis
2. Knip will detect unused dependencies more accurately than manual grep

Notes

• Knip version 5.x is required (major improvements over v4)
• Configuration is auto-detected for 100+ frameworks
• Monorepo support is first-class
• Use --reporter json for machine-readable output
• The --fix flag can auto-remove unused exports and dependencies