mopanc/depguard

**Find out in seconds whether an npm supply-chain attack reached your machine.** When a worm or a hijacked maintainer account ships malicious versions, npx depguard-cli exposure checks every project, global install and the npm download cache on your machine against 100,000+ known-malicious npm packages. It tells you exactly where a bad version is, whether it was installed, and what to rotate. depguard also audits packages before you install them and repositories before you open them. Zero runtime dependencies. Runs in the terminal or as an MCP server for Claude, Cursor, Windsurf and any MCP client.
Was I hit?
When something is found, every location is listed with the evidence and the steps to take:
What it looks at:
- **Every lock file** under the given paths (default: your home directory): npm, pnpm, yarn classic and berry, bun. Nested and duplicated copies count, so a malicious version hidden at node_modules/a/node_modules/b is found.
- **Globally installed packages** (npm root -g).
- **The npm download cache.** It proves a malicious tarball was downloaded on this machine, and when, even if the project that pulled it is gone.
Only exact matches are reported: a version is flagged only when it falls inside a known-malicious range, and clean versions of packages that were once compromised are never flagged. The data comes from the GitHub Advisory Database, both malware advisories and advisories for legitimate packages that were hijacked to ship malware, refreshed daily. The exit code is 2 when something is found, so it can gate CI:
Why depguard
I work on industrial software where every event has to be logged and recoverable — customers trust the system because the audit trail makes the system trustworthy. When I started wiring AI coding agents into our internal stack, I realised the npm ecosystem treats supply-chain integrity as someone else's problem: install 1,000 packages, hope for the best. depguard brings the same auditability mindset to JavaScript dependencies — verify before installing, audit what's already there, generate an SBOM your security team can actually use.
Zero runtime dependencies — because a security tool that pulls in 200 transitive packages is the joke that writes itself.
Install
MCP server (primary use case)
depguard exposes 15 MCP tools over stdio. Add it to any MCP-compatible client and your AI agent calls them automatically when it's about to install something, audit a project, or review code.
**Setup, Claude Code one-liner:**
**Setup — generic MCP config** (Claude Desktop, Cursor, Windsurf, Continue.dev, Cline, Roo Code):
The 15 tools
| Tool | Use it when |
|------|-------------|
| depguard_exposure | **"Was I hit by this attack?"** Scans every lock file, global install and the npm cache for known-malicious versions, with locations, evidence and remediation steps |
| depguard_guard | About to install package Y → pre-install verify + audit + allow/warn/block |
| depguard_should_use | Need functionality X → recommend install / use-native / write-from-scratch |
| depguard_audit_workspace | **Just cloned a repo, before opening it in any IDE.** Lists files that auto-execute on workspace open (VS Code tasks runOn:folderOpen, devcontainer lifecycle, .envrc, JetBrains run configs, Makefile, .gitattributes, committed git hooks). Defends against fake-interview / take-home-test malware. |
| depguard_audit_project | Audit a whole project — direct deps, transitives via lockfile, packageManager field |
| depguard_remediate | "100 vulnerabilities, which 5 direct deps do I bump?" — groups transitives by parent, sorted by severity weight |
| depguard_audit | Deep dive on one package (vulnerabilities + static code analysis + install scripts) |
| depguard_audit_bulk | Compare A vs B vs C in one call |
| depguard_audit_deep | Full transitive tree audit for one package |