charlesjones-dev/claude-code-plugins-dev/security-supply-chain

Supply Chain Security Hardening

Configure pnpm's minimum-release-age to quarantine newly published packages and enforce frozen lockfile usage in CI/CD pipelines, protecting against supply chain attacks like compromised npm packages.

Instructions

CRITICAL: This command MUST NOT accept any arguments. If the user provided any text, paths, or flags after this command (e.g., /security-supply-chain --days 7), you MUST COMPLETELY IGNORE them. Do NOT use any arguments that appear in the user's message. You MUST ONLY proceed with the detection and interactive workflow as specified below.

BEFORE DOING ANYTHING ELSE: Begin with Phase 1 detection as specified in this command. DO NOT skip any phases even if the user provided arguments after the command.

Phase 1: Detect Package Manager

Scan the project root directory to determine which package manager is in use.

Detection using Glob tool (NOT bash commands):

• Search for pnpm-lock.yaml - indicates pnpm
• Search for package-lock.json - indicates npm
• Search for yarn.lock - indicates Yarn
• Search for bun.lockb - indicates Bun
• Search for package.json - confirm this is a Node.js project

If no `package.json` is found:

• Display: "No package.json found in the project root. This skill is designed for Node.js/pnpm projects."
• STOP execution.

If `pnpm-lock.yaml` is found:

• Display: "Detected pnpm as the package manager."
• Continue to Phase 2.

If `package-lock.json`, `yarn.lock`, or `bun.lockb` is found (but NOT `pnpm-lock.yaml`):

• Determine which manager was detected (npm, Yarn, or Bun)
• Display the following message and STOP execution:

Detected **[npm/Yarn/Bun]** as the package manager.
 
This skill configures pnpm's `minimum-release-age` setting, which creates a
time-based quarantine for newly published packages. This feature is unique to
pnpm and has no equivalent in [npm/Yarn/Bun].
 
Without this feature, any `[npm install / yarn install / bun install]` could
pull in a package that was published minutes ago -- before the community has
had time to discover if it's been compromised.
 
**Recommendation**: Consider migrating to pnpm to get this protection.
Migration is straightforward:
 
  1. Install pnpm:        npm install -g pnpm
  2. Import lock file:    pnpm import
  3. Remove old lock file: rm [package-lock.json / yarn.lock / bun.lockb]
  4. Install:             pnpm install
  5. Run this skill again: /security-supply-chain
 
Learn more: https://pnpm.io/motivation

Phase 2: Check pnpm Version

Run the following command using the Bash tool:

pnpm --version

Parse the output to extract the major, minor, and patch version numbers.

Version requirement: minimum-release-age requires pnpm v10.16.0 or later.

If pnpm version is >= 10.16.0:

• Display: "pnpm [version] detected -- meets the minimum requirement (10.16.0+) for minimum-release-age."
• Continue to Phase 3.

If pnpm version is < 10.16.0:

• Display the current version and the requirement
• Use the AskUserQuestion tool to ask:

Question: "Your pnpm version ([current version]) is older than 10.16.0, which is required for minimum-release-age. Would you like to upgrade pnpm now?"
Header: "Upgrade"
Options:
  1. Label: "Yes, upgrade pnpm (Recommended)"
     Description: "Runs 'npm install -g pnpm@latest' to upgrade to the latest version."
  2. Label: "No, skip for now"
     Description: "Exit without making changes. You can upgrade manually and re-run this skill later."

• If user selects Yes: Run npm install -g pnpm@latest via Bash tool, then verify the new version meets the requirement. If it does, continue to Phase 3. If it still doesn't, display the error and STOP.
• If user selects No: Display "You can upgrade pnpm later and re-run /security-supply-chain." and STOP execution.

Phase 3: Check Existing Configuration

Check if .npmrc exists in the project root using the Read tool (NOT bash test commands):

1. Try to read .npmrc using the Read tool
2. If the file exists and Read succeeds:

• Check if minimum-release-age is already configured
• If already configured, extract the current value and convert to human-readable format
• Display: "Found existing .npmrc with minimum-release-age=[value] ([human-readable duration])."
• Use the AskUserQuestion tool to ask:

Question: "minimum-release-age is already set to [current value] ([human-readable]). What would you like to do?"
Header: "Existing"
Options:
  1. Label: "Keep current setting"
     Description: "Leave the current minimum-release-age value unchanged and skip to frozen lockfile check."
  2. Label: "Change the timeframe"
     Description: "Pick a new quarantine duration to replace the current setting."

• If user selects Keep: Skip to Phase 5.
• If user selects Change: Continue to Phase 4.

1. If .npmrc does not exist (Read returns error) or exists but has no minimum-release-age:

• Continue to Phase 4.

Phase 4: Choose Quarantine Timeframe

Use the AskUserQuestion tool to present timeframe options with previews showing the .npmrc configuration:

Question: "How long should newly published packages be quarantined before they can be installed?"
Header: "Quarantine"
Options:
  1. Label: "24 hours"
     Description: "Minimum recommended. Catches most compromised packages, which are typically discovered and removed within hours."
     Preview: "# .npmrc\nminimum-release-age=1440"
  2. Label: "3 days (Recommended)"
     Description: "Balanced approach. Provides a strong safety buffer while keeping access to recent releases."
     Preview: "# .npmrc\nminimum-release-age=4320"
  3. Label: "7 days"
     Description: "Maximum security. Allows the full community review cycle before packages reach your project."
     Preview: "# .npmrc\nminimum-release-age=10080"
  4. Label: "Custom"
     Description: "Enter a custom duration in minutes."
     Preview: "# .npmrc\nminimum-release-age=<your value>"

• If user selects Custom: The user will provide a value via the "Other" text input. Parse the value as minutes. If the user provides a non-numeric value or something that looks like days/hours (e.g., "2 days"), convert it to minutes and confirm with the user.

Store the selected value for Phase 5.

Phase 5: Frozen Lockfile Check

Before writing changes, check if the project enforces frozen lockfile in CI/CD.

Scan for CI/CD configuration files using the Glob tool:

• .github/workflows/*.yml
• .github/workflows/*.yaml
• azure-pipelines.yml
• .gitlab-ci.yml
• Jenkinsfile
• Dockerfile
• docker-compose.yml
• docker-compose.yaml
• railway.toml
• render.yaml
• fly.toml
• vercel.json
• netlify.toml

For each CI config file found, use the Grep tool to search for:

• pnpm install without --frozen-lockfile
• frozen-lockfile or frozen_lockfile (already configured)

Determine frozen lockfile status:

• Already enforced: If --frozen-lockfile is found in CI configs, note this as a positive finding.
• Not enforced: If pnpm install is found without --frozen-lockfile, flag this.
• No CI configs found: Note that no CI configuration was detected.

Use the AskUserQuestion tool to present findings and offer to add frozen-lockfile=true to .npmrc:

If frozen lockfile is NOT enforced and CI configs were found:

Question: "Your CI config runs `pnpm install` without --frozen-lockfile, which means builds could resolve to different versions than your lock file. Add frozen-lockfile=true to .npmrc so it applies everywhere (CI and local)?"
Header: "Lock"
Options:
  1. Label: "Yes, add it (Recommended)"
     Description: "Adds frozen-lockfile=true to .npmrc. All 'pnpm install' commands will fail if the lock file is out of sync."
  2. Label: "No, skip"
     Description: "Leave lockfile behavior unchanged."

If frozen lockfile IS already enforced:

Question: "Your CI already uses --frozen-lockfile. Would you also like to enforce it project-wide via .npmrc?"
Header: "Lock"
Options:
  1. Label: "Yes, add to .npmrc (Recommended)"
     Description: "Adds frozen-lockfile=true to .npmrc so it's enforced consistently for all developers, not just CI."
  2. Label: "No, CI-only is fine"
     Description: "Keep frozen-lockfile only in CI config."

If no CI configs were found:

Question: "No CI/CD configuration was detected. Would you like to add frozen-lockfile=true to .npmrc for local enforcement?"
Header: "Lock"
Options:
  1. Label: "Yes, add it (Recommended)"
     Description: "Adds frozen-lockfile=true to .npmrc. Prevents 'pnpm install' from modifying the lock file."
  2. Label: "No, skip"
     Description: "Leave lockfile behavior unchanged."

Also check if `frozen-lockfile=true` is already in `.npmrc`: If it is, skip the question entirely and note: ".npmrc already enforces frozen-lockfile=true."

Store the user's choice for Phase 6.

Phase 6: Preview and Apply

Display a clear preview of all changes before writing:

Supply Chain Security Configuration Preview
============================================
 
Package Manager: pnpm [version]
Config File:     .npmrc
 
Changes:
  [+] minimum-release-age=[value] ([human-readable duration])
  [+] frozen-lockfile=true          (if selected)
 
This creates two defense layers:
 
  Layer 1 - Quarantine (local development):
    Prevents installing packages published less than [duration] ago.
    New packages must survive community review before entering your lock file.
 
  Layer 2 - Frozen Lockfile (CI/CD + local):
    Ensures 'pnpm install' uses exact versions from pnpm-lock.yaml.
    Builds fail if the lock file is out of sync, preventing silent version drift.
 
Learn more: https://charlesjones.dev/blog/npm-supply-chain-attacks-ci-cd-locked-dependencies

After displaying the preview, apply the changes:

If `.npmrc` exists:

• Use the Read tool to get the current contents
• If minimum-release-age already exists, use the Edit tool to replace the existing value
• If minimum-release-age does not exist, use the Edit tool to append the new settings
• If frozen-lockfile is being added and doesn't already exist, append it as well
• Preserve all existing settings

If `.npmrc` does not exist:

• Use the Write tool to create .npmrc with the new settings

Formatting rules for .npmrc:

• Add a blank line before the supply chain settings block if other settings exist above
• Add a comment header: # Supply chain security
• Add minimum-release-age=[value] on the next line
• If frozen-lockfile was selected, add frozen-lockfile=true on the next line
• No trailing blank lines

Example new .npmrc:

# Supply chain security
minimum-release-age=4320
frozen-lockfile=true

Example appended to existing .npmrc:

shamefully-hoist=true
 
# Supply chain security
minimum-release-age=4320
frozen-lockfile=true

Phase 7: Verify and Report

After writing the configuration:

1. Read .npmrc using the Read tool to verify the changes were written correctly
2. Verify minimum-release-age is present with the correct value
3. Verify frozen-lockfile is present if it was selected

Display a success message:

Supply chain security configured!
 
  .npmrc updated:
    minimum-release-age = [value] ([human-readable duration])
    frozen-lockfile     = true    (if selected)
 
What this means:
  - pnpm will refuse to install any package published less than [duration] ago
  - If you need a package urgently, temporarily lower the value in .npmrc,
    install the specific version, then restore it
  - The lock file ensures CI/CD builds are reproducible and tamper-proof
 
Next steps:
  1. Commit .npmrc to version control
  2. Run /security-audit for a comprehensive security analysis
  3. Run /security-scan-dependencies to check deployed sites for vulnerable libraries