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Supply Chain Risk Auditor

Free

Audit project dependencies for supply-chain risks.

by trailofbits6.5k stars on trailofbits/skills
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Updated Aug 10, 2026
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Free · Opens the source repo

What Supply Chain Risk Auditor does

The Supply Chain Risk Auditor skill provides a systematic approach to evaluating the dependencies of a project for potential supply-chain risks. It focuses on direct dependencies, as well as the entire lockfile tree, to identify issues such as version mismatches, abandoned upstreams, npm publisher concentration, and the execution of install-time scripts. By utilizing deterministic scripts, this skill ensures that the data collected is accurate and reliable, allowing developers to make informed decisions based on concrete evidence rather than estimates.

The auditing process begins by confirming that the target project directory contains the necessary manifest files, such as package.json, pyproject.toml, or go.mod. Once verified, the skill checks the authentication status with GitHub to ensure it can make the required API requests for accurate data collection. The collector script gathers information on each dependency, producing a JSON output that serves as the foundation for a detailed risk report. This report highlights any assessed risks and provides a clear overview of the dependency landscape.

One of the key advantages of the Supply Chain Risk Auditor is its emphasis on objective data collection. It avoids common pitfalls associated with manual data gathering, such as incorrect maintainer counts or misinterpreted download statistics. Instead, it relies on automated scripts to provide a consistent and reproducible assessment of each dependency. The final report generated is designed to be clear and actionable, enabling developers to prioritize their responses based on the findings.

This skill is particularly useful for software developers and security professionals who need to assess the risks associated with third-party packages before integrating them into their projects. It is an essential tool for those looking to maintain a secure and robust software supply chain, ensuring that dependencies are thoroughly vetted before use.

When to use it

Use this skill when you need to audit dependencies for potential supply-chain risks or before engaging with third-party packages.

When not to use it

This skill is not suitable for license compliance auditing or scanning the target's source for vulnerabilities.

What you can build with it

Auditing for a New Project

When starting a new project, use this skill to assess the risks associated with all dependencies before integrating them.

Pre-Engagement Security Review

Before engaging with third-party packages, run this skill to ensure all dependencies are secure and reliable.

Regular Dependency Maintenance

In ongoing projects, periodically use this skill to audit dependencies and address any emerging risks.

How to install Supply Chain Risk Auditor

View source

1. Install with the skills CLI

npx skills add trailofbits/skills/supply-chain-risk-auditor --agent claude-code

2. Or install it manually

Download the skill folder and drop it into ~/.claude/skills/ for all projects, or .claude/skills/ to scope it to one repo. Restart Claude Code so it picks up the new skill.

Anthropic's agentic coding CLI, and the reference implementation of Agent Skills. Drop a skill folder into ~/.claude/skills and Claude Code loads it automatically whenever a task matches the skill's description. Claude Code docs

Inside SKILL.md

Written by trailofbits

Supply Chain Risk Auditor

Generates a supply-chain risk report for a project's direct dependencies (npm, PyPI, Go), plus an advisory sweep of everything its lockfile resolves. Two deterministic scripts do the measuring; your job is the judgment they refuse to automate.

Why the scripts do the measuring, not you

Every figure in this report is a claim about somebody else's project, and hand-collected figures were measured wrong before this skill was rebuilt around scripts: GitHub contributor counts said five-plus people maintain lodash where npm's ACL says one, and gh saw zero downloads for a package that moves 164 million a week. Do not estimate maintainer counts, downloads, staleness, or CVE history from gh, web search, or memory — run the collector, and quote what it measured.

The scripts enforce two rules worth knowing before you read their output:

  • Unavailable data is never evidence of risk. Every criterion resolves to assessed-clean, assessed-flagged, or unassessable-with-a-reason.
  • An absent measurement is never a clean verdict. A run that measured nothing exits non-zero instead of printing a report that finds nothing.

Workflow

  1. Confirm the target directory has manifests: package.json, pyproject.toml, requirements*.txt, or go.mod. If none exist, say so and stop — do not audit an ecosystem this collector does not parse by hand. Lockfiles read for exact versions and the transitive sweep: package-lock.json/npm-shrinkwrap.json, uv.lock, and a go 1.17+ go.mod. yarn.lock, pnpm-lock.yaml, and poetry.lock are not read — the report says so when they are present, and versions fall back to pins or the latest release.

  2. Check gh auth status. Unauthenticated GitHub allows 60 requests/hour against 5,000, and the collector makes several per dependency; expect repository criteria to come back unassessable without it. Say so rather than fixing it silently.

  3. Collect, then render. Put outputs somewhere outside the audited repository unless asked otherwise:

    uv run {baseDir}/scripts/collect.py <project-dir> --json <out-dir>/findings.json
    uv run {baseDir}/scripts/render.py <out-dir>/findings.json --out <out-dir>/report.md
    

    Expect a few minutes for ~50 dependencies — several HTTP requests per dependency, more with many Go modules, and slower without authenticated gh. If collect.py exits non-zero, it is refusing to report — relay its message verbatim instead of retrying or working around it.

  4. Read report.md and findings.json. The report is the deliverable; the JSON carries the datum behind every verdict when you need to cite one.

  5. Add what the collector cannot, clearly separated from what it measured:

    • A short narrative for this reader: what to act on first, and why.
    • Upgrade paths for advisory findings — check whether the fix is a patch or a major version away.
    • Replacement candidates for abandoned or archived dependencies. Verify a candidate exists in the registry before naming it, and label these as judgment, not measurement.
    • For flagged install scripts: whether npm ci --ignore-scripts is viable for this project's build.

Style for what you add

Write added prose the way a security report reads, and apply the same register to the report addendum and the final reply alike — replies get pasted into tickets and reports verbatim. State the finding, the datum behind it, and the action.

  • Impersonal and declarative: no first or second person ("I ran the collector", "you should upgrade"), no contractions, no exclamation points.
  • Active voice, with the subject matter as the actor: "upgrading to 1.19.0 clears all 25 advisories", not "it is recommended that axios be upgraded".
  • Objective: no intensifiers or subjective framing ("very", "significant", "fortunately"), and no guesses about why the project chose what it chose.
  • Tense: past for what the audit did, present for the state of the dependencies, future for the consequences of acting or not.
  • Constructive: a recommendation names the action and its cost, never a culprit.

If the report-writing:writing-style skill is available in the session, follow it — it is the full version of this register.

The rendered report carries facts only. The interpretive rules below are instructions to you, not content for the reader — do not copy them into the deliverable as caveats or framing.

Reading the report

  • Unassessable is not risk. PyPI publishes no maintainer ACL and Go has no registry; those rows say what could not be known, not what is wrong.
  • The coverage table bounds every claim. "No advisories" means "none among what was assessed" — check the assessed count before repeating a clean verdict.
  • Quote figures verbatim. Do not re-derive, round, or embellish the report's numbers; every one is reproducible from the artifact.
  • Absence from the findings is not endorsement. A dependency with no findings was measured against these criteria only.

Rationalizations to reject

  • "gh can give me maintainer counts faster than the collector." Measured wrong — repo contributors and registry publish rights are different populations.
  • "No findings, so the dependencies are safe." Read the coverage table; on PyPI and Go, half the criteria are structurally unassessable.
  • "The unassessable rows would just confuse the reader; I'll drop them." They are the boundary of every claim in the report. Dropping them turns partial coverage into a clean bill of health, which is the failure this skill was rebuilt to prevent.
  • "The version is probably close enough." A range checked at latest-release and a lockfile-resolved version are different claims; the report labels which one it makes. Keep the label.

When not to use

  • License compliance auditing.
  • Scanning the target's own source for vulnerabilities or secrets — this skill never reads dependency source, only registry, advisory, and repository metadata.
  • Judging whether the project installs or builds. The audit is designed to work from nothing more than the dependency list — manifests and lockfiles — and never installs, builds, or executes anything. Broken installs and import-time breakage are out of scope, and worth saying so if the user seems to expect them.
  • Ecosystems other than npm, PyPI, and Go; say the ecosystem is unsupported rather than improvising an audit for it.

Frequently asked questions about Supply Chain Risk Auditor

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