dependency-vetting

name	dependency-vetting
description	Vet new package dependencies before installation. Triggers when adding packages via pip, npm, yarn, or similar package managers. Checks for typosquatting, known vulnerabilities, low adoption (potential supply chain risk), and package metadata anomalies. Use when: - User asks to install a new package - pip install, npm install, yarn add commands detected - requirements.txt or package.json modifications - User asks "is this package safe?" Blocks: Typosquats, critical vulnerabilities Warns: Low adoption, suspicious metadata
allowed-tools	Bash, Read, WebFetch
model	haiku

Dependency Vetting Skill

Purpose

Prevent supply chain attacks by vetting packages before installation:

• Detect typosquatting (e.g., reqeusts instead of requests)
• Check for known vulnerabilities (CVEs)
• Verify package legitimacy (download counts, age, maintainer)
• Warn on low adoption or suspicious patterns

---

When to Trigger

Auto-trigger when detecting:

• pip install <package>
• pip3 install <package>
• npm install <package>
• yarn add <package>
• Modifications to requirements.txt, package.json, pyproject.toml

---

Vetting Protocol

Step 1: Parse Package Name

# Extract package name and version from command
# Examples:
#   pip install requests==2.28.0  → requests, 2.28.0
#   npm install lodash@4.17.21    → lodash, 4.17.21
#   pip install -r requirements.txt → parse file

Step 2: Typosquatting Check

Popular packages to check against:

Python:

requests, numpy, pandas, flask, django, fastapi, pydantic,
sqlalchemy, pytest, black, mypy, ruff, httpx, aiohttp,
beautifulsoup4, pillow, scipy, matplotlib, tensorflow, torch

JavaScript:

react, vue, angular, express, lodash, axios, moment,
webpack, babel, eslint, prettier, typescript, jest, mocha,
next, gatsby, tailwindcss, styled-components

Typosquatting detection:

def is_typosquat(package_name: str, known_packages: list[str]) -> tuple[bool, str]:
    """Check if package name is suspiciously similar to a known package."""
    import difflib

    for known in known_packages:
        # Exact match is fine
        if package_name == known:
            return False, ""

        # Check similarity ratio
        ratio = difflib.SequenceMatcher(None, package_name, known).ratio()
        if ratio > 0.85 and package_name != known:
            return True, f"Suspiciously similar to '{known}' (similarity: {ratio:.0%})"

        # Common typosquatting patterns
        patterns = [
            package_name.replace('-', ''),      # request vs requests
            package_name.replace('_', '-'),     # python_dateutil
            package_name + 's',                 # request → requests
            package_name[:-1] if len(package_name) > 3 else package_name,  # requests → request
        ]
        if known in patterns:
             , 

     , 

Step 3: Package Existence Verification

Python (PyPI):

# Check if package exists
pip index versions $PACKAGE_NAME 2>&1

# Or use API
curl -s "https://pypi.org/pypi/$PACKAGE_NAME/json" | jq '.info'

JavaScript (npm):

npm view $PACKAGE_NAME --json 2>&1

If package doesn't exist: BLOCK - likely typo or malicious attempt

Step 4: Metadata Analysis

Extract and analyze:

{
  "name": "package-name",
  "version": "1.2.3",
  "author": "author-name",
  "maintainers": ["maintainer1", "maintainer2"],
  "downloads_last_month": 1500000,
  "first_published": "2015-03-15",
  "last_updated": "2024-01-10",
  "repository_url": "https://github.com/org/repo",
  "license": "MIT"
}

Red flags:

• ⚠️ Package < 6 months old with low downloads
• ⚠️ No repository URL
• ⚠️ Author name similar to popular package author
• ⚠️ Recently changed maintainer
• ⚠️ No license specified
• ⚠️ Unusual install scripts

Step 5: Vulnerability Check

Python:

# Using pip-audit
pip-audit --requirement requirements.txt

# Or check specific package
pip-audit $PACKAGE_NAME

JavaScript:

# Using npm audit
npm audit --json

# Or check specific package
npm audit $PACKAGE_NAME

Severity levels:

• Critical: Known RCE, SQL injection, etc. → BLOCK
• High: Serious vulnerabilities → WARN (require acknowledgment)
• Medium/Low: → WARN (inform user)

---

Decision Matrix

Condition	Action	Message
Typosquat detected	BLOCK	"Package '$name' appears to be a typosquat of '$real'. Did you mean '$real'?"
Package doesn't exist	BLOCK	"Package '$name' not found. Check spelling."
Critical vulnerability	BLOCK	"Package has critical vulnerability CVE-XXXX. Use alternative or pin older version."
High vulnerability	WARN	"Package has high-severity vulnerability. Proceed with caution?"
Low downloads (<1000/month)	WARN	"Package has very low adoption. Verify it's legitimate."
New package (<3 months)	WARN	"Package is very new. Verify maintainer reputation."
No repository	WARN	"Package has no linked repository. Cannot verify source."
Clean	ALLOW	"Package vetted: [summary of checks passed]"

---

Output Format

{
  "package": "requests",
  "version": "2.28.0",
  "verdict": "ALLOW | WARN | BLOCK",
  "reason": "Brief explanation",

  "checks": {
    "typosquatting": {"passed": true, "details": null},
    "exists": {"passed": true, "details": "Found on PyPI"},
    "vulnerabilities": {"passed": true, "details": "No known CVEs"},
        
        
        
  

    |  | 

---

Example Interactions

Typosquat blocked:

User: pip install reqeusts

Skill output:
⛔ BLOCKED: Package 'reqeusts' appears to be a typosquat of 'requests'

Did you mean: pip install requests

This is a common supply chain attack vector. The legitimate package
is 'requests' (with correct spelling).

Low adoption warning:

User: pip install obscure-tool-xyz

Skill output:
⚠️ WARNING: Package 'obscure-tool-xyz' has low adoption

- Downloads last month: 47
- First published: 2024-11-01 (2 months ago)
- No linked repository

This package has very limited community validation.
Proceed with installation? [yes/no]

Critical vulnerability blocked:

User: pip install vulnerable-lib==1.0.0

Skill output:
⛔ BLOCKED: Package has critical vulnerability

CVE-2024-12345: Remote Code Execution
Affected versions: < 1.2.0
Fixed in: 1.2.0

Recommendation: pip install vulnerable-lib>=1.2.0

---

Remember

• Block typosquats aggressively - These are almost always malicious
• Warn on low adoption - But allow if user confirms
• Check vulnerabilities - Critical = block, High = warn
• Provide alternatives - When blocking, suggest the correct package
• Log all decisions - For audit trail