NPMScan

Statically scans a package's preinstall/install/postinstall/prepare lifecycle scripts AND the file(s) they reference — fetched directly from the published tarball, not just the command string in package.json — against npmscan's documented red-flags rubric (/docs/red-flags): child_process use, network calls, access to sensitive paths/env (.ssh, .aws, .npmrc, *TOKEN/*KEY), obfuscation, remote binaries hosted off trusted CDNs, writes to HOME, Discord/Telegram/Pastebin exfil endpoints, eval on decoded strings, chmod+exec of downloaded binaries, and CI-metadata telemetry — plus a possibleTyposquatOf name check. Returns a weighted totalScore and riskTier ('none'/'low'/'moderate'/'high'/'critical'). This is a heuristic static scan, not proof of malice or a guarantee of safety: it doesn't execute any code, can't see behavior gated on runtime conditions, and does NOT check maintainer/ownership history (a separate red-flags signal this tool doesn't cover). Use get_package/get_package_version first for the raw script listing; use this when you need to know what an install script actually does, not just that one exists.

analyze_install_script

Recursively resolves one or more direct/root packages' dependency graphs — e.g. the "dependencies" section of a package.json — up to maxDepth levels deep (default 2, max 3) and batch-checks every resolved package@version against OSV.dev, so vulnerabilities buried several levels down (which would never show up from checking direct dependencies alone) still surface. `summary` is a one-sentence, deterministic recap (packages scanned, unresolved count, vulnerable count and which roots pulled them in) — read it first. The `vulnerablePaths` field directly answers "which of my dependencies pulled this in" by naming the root package(s) responsible for each vulnerable transitive package; `nodes` has the full resolved graph (depth, parents, resolutionError) for deeper inspection. Scope/limits worth knowing before trusting a "clean" result: only the "dependencies" field is followed (not devDependencies/peerDependencies/optionalDependencies); each range is resolved independently per branch via semver max-satisfying against published versions — this does NOT emulate npm/yarn's actual node_modules hoisting/dedup, so read results as "which vulnerable versions are reachable in the graph," not the exact installed layout; git/file/workspace/URL/npm-alias dependencies aren't resolvable from the registry and show up with a resolutionError instead of being silently skipped; and the whole traversal is capped at a total node budget — check `truncated`/`truncationNote` rather than assuming a large graph was scanned exhaustively. Prefer batch_query_vulnerabilities instead when you only need to check exact packages you already have a flat list for (faster, no graph walk).

analyze_transitive_dependencies

Given a GitHub repository URL, fetches its package.json (and, if present, a pnpm-lock.yaml/package-lock.json/yarn.lock — first one found wins, in that priority order) straight from the repo's default branch and runs the same vulnerability, license-compliance, install-script, and ownership-risk pipelines batch_query_vulnerabilities/check_license_compliance/analyze_install_script/check_maintainer_changes/check_package_provenance expose individually, in one call — no copy-pasting file contents required. A monorepo (package.json#workspaces, Yarn's {packages:[...]} form, or pnpm-workspace.yaml) is detected automatically: pnpm-lock.yaml and yarn.lock already record every workspace member's dependencies directly, and for package.json-only or package-lock.json repos this additionally lists the repo's file tree, resolves the declared glob patterns to member directories, and merges each member's dependencies into the audit (capped at 50 member packages) — see isMonorepo/workspacePatterns/workspacePackageCount/workspaceNote in the result. Every direct dependency (up to 100 per call, across the root and any merged workspace members) gets: an OSV.dev vulnerability check, a license-compliance verdict against the given policy (same default as check_license_compliance: only copyleft/network-copyleft/proprietary are violations unless you pass one), and a tarball-free install-script risk signal (installScriptScanScope: 'lifecycle-scripts-only'). Up to 10 of the packages that actually declare a lifecycle script — prioritized by already-vulnerable, then possible-typosquat, then whatever's left — additionally get the full tarball-fetching deep scan analyze_install_script itself runs (installScriptScanScope: 'deep-tarball-scan', with a populated installScriptFindings array); any remaining flagged packages past that cap keep the lighter signal only, noted in deepScanNote. Any package that comes back vulnerable at high/critical severity, a possible typosquat, or deprecated (ownershipRiskEligible) additionally gets check_maintainer_changes and check_package_provenance run against it — up to 5 such packages per call (ownershipRiskChecked), prioritized the same way as the deep install-script scan, populating maintainerRiskTier/maintainerFindings and provenanceRiskTier/provenanceFindings; remaining eligible packages past that cap are named in ownershipCheckNote. This is the most expensive tool in the suite (a repo lookup, a handful of file fetches, up to 100 registry doc fetches, one OSV batch call, up to 10 tarball fetches, up to 5 packages each getting a maintainer-history check plus a provenance check — the latter alone can fan out to ~8 more registry fetches on its own — and, for a monorepo needing enumeration, one file-tree listing plus up to 50 more manifest fetches) — don't call it in a loop across many repos.

audit_github_repository

Query OSV.dev for known vulnerabilities across a whole npm dependency inventory at once: either pass a flat {packages:[...]} list, or paste raw package.json / lockfile / CycloneDX JSON / SPDX JSON content via `content`. The tool normalizes npm dependencies first, then chunk-queries OSV behind the scenes so large SBOMs don't stop at the upstream 100-package batch limit. Each finding includes severity, a summary, CVE aliases, and the fixed version — not just a bare advisory ID — so a dependency audit answer doesn't need a follow-up call per flagged package. For an explicit `packages` list or raw `package.json` content — names that were never actually resolved against a registry, unlike a real lockfile/SBOM — package names are also cross-checked against the npm registry (capped at 200 unique names): a name that doesn't exist there would otherwise show a silent, indistinguishable `vulnerabilityCount: 0` — see `unresolvedPackages`/`existenceCheckNote` and do not read those entries as a clean bill of health.

batch_query_vulnerabilities

Given a list of packages (name + optional exact version or semver range — e.g. straight from a package.json "dependencies" object) and an optional allow/deny license policy, resolves each package's declared SPDX license and reports a compliance verdict per package. Classifies every license into one of permissive/weak-copyleft/copyleft/network-copyleft/proprietary/public-domain/unknown, and understands simple SPDX expressions: "(MIT OR GPL-3.0)" is compliant if EITHER side is permitted (a consumer may legally pick the clean alternative), "MIT AND Apache-2.0" requires both sides to pass, and "X WITH exception" is judged on X. A mixed/nested expression like "(MIT OR ISC) AND Apache-2.0" is reported as needsReview rather than guessed at. `policy.deny` entries always win over `policy.allow` (so a name can appear in both without a silent contradiction); with `policy.allow` set, anything not matching it is a violation (unproven is treated as non-compliant); with neither given, the default policy flags only copyleft/network-copyleft/proprietary (e.g. GPL/AGPL/UNLICENSED) — weak-copyleft (LGPL/MPL/EPL) and unrecognized license strings are surfaced but not auto-flagged. Policy entries accept an exact SPDX id, a family prefix ("GPL" catches GPL-2.0/GPL-3.0-only/etc.), or a category name. This reads only the registry-declared `license` field — it does not fetch or parse LICENSE file contents from the source repository.

check_license_compliance

Reconstructs a package's maintainer-change history straight from the npm packument — every published version carries the maintainers-list SNAPSHOT as it stood at that publish plus who actually ran `npm publish` (`_npmUser`), so diffing consecutive snapshots in publish-time order recovers exactly who was added or removed and when, with no extra API calls. Flags: (1) a maintainer added recently who then published a release shortly afterward on a package with real prior history — the account-takeover/hostile-handoff shape behind incidents like ua-parser-js, event-stream, and the 2025 chalk/debug ('qix') compromise; (2) a full, sudden replacement of the entire maintainer list; (3) a long-standing maintainer quietly dropped from the list; (4) a maintainer-list change that happened on npm's site AFTER the latest release — not yet tied to any published version, which is the more urgent case since it means access changed hands but nothing has shipped with it yet. Also cross-checks the declared GitHub repository: whether it still resolves to the same owner/name (a transfer/rename), whether it's reachable at all, and whether the latest npm release landed long after any real push activity there — repository.ownerLogin/ownerAvatarUrl name and show the CURRENT owning account (the new one after a transfer, not the one originally declared in package.json), with ownerAvatarUrl served from our own /api/github/avatar proxy rather than linking avatars.githubusercontent.com directly, both null whenever the repo check itself didn't reach GitHub. Use get_package/check_package_provenance first for the package's general health and publish-integrity signals; use this specifically for the 'who controls this package, and did that change recently' question. If this flags a newly added or fully turned-over maintainer, follow up with check_maintainer_blast_radius on that maintainer's username — it lists every other package the same account currently touches and flags a tight publish-time cluster across them, the 'did this compromise hit just one package or a dozen' question this tool can't answer on its own.

check_maintainer_changes

Checks whether a package version was published with npm's own Sigstore-backed publish provenance (`npm publish --provenance`), and cross-checks that provenance against reality rather than just reporting its presence. Three checks: (1) parses the SLSA build attestation (declared source repo, commit, builder identity, GitHub Actions run URL) and flags a builder that isn't GitHub-hosted, or an attested source repo that doesn't match package.json's own `repository` field; (2) when this version LACKS provenance, checks whether most peer packages (same npm scope, or same maintainer for an unscoped name) DO have it — a package that's the odd one out in an org that otherwise always publishes from CI is a real anomaly, not proof of malice; (3) fetches package.json from the source repository at the exact attested commit (or a best-effort matching git tag when no provenance/commit is available) and diffs its install-lifecycle scripts (preinstall/install/postinstall/prepare) and dependency names against what's actually in the published tarball — this is the single highest-signal check here, since a script or dependency that exists on npm but was never committed is exactly the pattern of a stolen-npm-token publish that bypasses CI (the event-stream/ua-parser-js incident shape). This is a heuristic, structural check: it does NOT cryptographically re-verify the Sigstore bundle (Fulcio cert chain, Rekor inclusion proof) — it trusts that npm's registry already refused to accept a publish that failed that verification, and checks the CONTENT of what the registry reports instead. Most packages don't use --provenance yet, so its bare absence is never scored on its own — only an org-norm anomaly or an actual source mismatch is. Use get_package/get_package_version first for basic package info; use this specifically to assess publish-integrity risk.

check_package_provenance

Given 2-5 candidate packages for the same job (e.g. "axios vs got vs node-fetch"), fetches the same registry/popularity/maintenance/vulnerability enrichment get_package computes for each one in parallel and returns a structured side-by-side plus a deterministic, reasoned pick. Each candidate gets downloads + trend, popularityTier/maintenanceTier, GitHub stars, TypeScript support, license, deprecated status, latest-version vulnerability status, a lightweight installScriptRisk signal (scans lifecycle script command strings for known red flags — does NOT fetch the tarball; call analyze_install_script on a specific candidate for that deeper scan), and installSize (the candidate's own dist.unpackedSize plus a transitive rollup — summed dist.unpackedSize across its resolved dependency tree, walked up to depth 2 / 60 nodes per candidate; `installSize.transitive.truncated`/`sizeUnknownCount` flag when that sum is partial rather than pretending it's exact — call analyze_transitive_dependencies on a specific candidate for the full graph). `differentiators` names which candidates stand out on each dimension (most downloads, only ones with TS types, which are deprecated/vulnerable/flagged as a typosquat/install-script risk, smallest/largest install size). `recommendation.pick` is chosen deterministically from a weighted score (popularity, maintenance, deprecation, vulnerabilities, typosquat flag, install-script risk, TS support, GitHub stars — install size is reported but not scored) — never a deprecated or typosquat-flagged candidate — with `rationale` explaining why and `confidence` reflecting how close the top two scored. A name that can't be resolved (typo, unpublished, malformed) still appears in `candidates` with `found:false` and `resolutionError` set rather than failing the whole call; duplicate names in the input are rejected.

compare_packages

Compares two raw snapshots of a package.json, package-lock.json (npm v1-v3), yarn.lock (classic v1 or Berry), or pnpm-lock.yaml — e.g. before/after a PR — and reports which packages were added, removed, or version-bumped. For every added or bumped package (up to 100 per call), also checks whether its resolved version carries a preinstall/install/postinstall/prepare lifecycle script that the before-version did NOT have (`installScriptIntroduced`, the highest-signal field here — a routine-looking patch bump quietly adding a postinstall is exactly the shape of a compromised-maintainer supply-chain attack) and batch-checks it against OSV.dev, reporting `vulnerabilityDelta` (introduced/fixed/still-vulnerable/still-clean) rather than just a bare isVulnerable flag. Scope notes: only direct dependencies are diffed for package.json/package-lock.json/pnpm-lock.yaml (their own formats distinguish direct from transitive); yarn.lock has no such distinction, so its side of the diff covers every resolved package in the file — expect a larger added/removed count when diffing a yarn.lock, and check `comparisonNote` when the two snapshots are different formats. The install-script check is presence-only (read from the registry packument or lockfile metadata, not a tarball content scan) — use analyze_install_script for a deep-dive on anything flagged here. Ideal for a CI gate reviewing a dependency-changing PR.

diff_dependencies

Given an npm username, finds every package npm's own maintainer:<username> search index currently returns for that account (registry.npmjs.org's /-/v1/search — the same reverse lookup npmjs.com's own site search uses; the public registry API has no dedicated 'list packages by maintainer' endpoint otherwise) and looks for a tight cluster of packages whose LATEST version was published within a short rolling window of each other. That's the shape of a compromised-account supply-chain attack: a stolen or phished credential doesn't get used on one package, it gets used on every package that account can publish to, usually within hours — the exact pattern behind the September 2025 chalk/debug ('qix') compromise, which hit roughly 18 packages within about 2 hours. A large total package count is NOT itself a red flag — many legitimate maintainers publish hundreds of packages over a career — only a tight publish-time cluster is scored, weighted up by how many packages it includes and by their combined weekly downloads/dependentsCount, since a burst touching a handful of near-zero-download packages is a very different event than one touching something with billions of weekly downloads. A cluster where most of the packages share one npm scope (e.g. @docusaurus/*) is dampened, since that's the shape of a project's own monorepo doing one coordinated release, not a compromised account spread across unrelated packages — this is why a large official org account (e.g. facebook/fb) publishing several of its own monorepos still lands well below what a plain sum of its cluster count would suggest. Multiple distinct clusters on one account combine with diminishing returns (the single worst cluster counts in full; each additional one contributes half the previous one's weight), not a plain sum — an account that does many independent, legitimate coordinated releases over its lifetime should not accumulate an unbounded score purely from being prolific. avatarUrl is the same Gravatar image npmjs.com's own profile page shows for this account, derived from the email already public in the registry's own maintainer records but served from our own /api/avatar/:hash proxy rather than linking gravatar.com directly (null only if no returned package still lists an email for this exact username). Each returned package's CURRENT maintainer list is cross-checked against the queried username (isCurrentMaintainer), since access is often already revoked by the time this runs. Natural follow-up to check_maintainer_changes: when that tool flags a newly added or fully turned-over maintainer on one package, call this with that maintainer's username to see whether the same account touched other packages around the same time. Known limitations: npm's search index is a text-relevance index, not a guaranteed-complete/real-time reverse index (results can lag or omit edge cases); results are capped at one page (up to 250 packages, ranked by npm's own relevance/popularity scoring, NOT by recency) so a very large footprint may be truncated (see resultsTruncated/totalPackagesFound) and a real cluster outside that page could be missed; and lastPublished reflects only each package's latest version, not its full history. npmscanUrl is this account's profile page on npmscan itself; npmProfileUrl is the account's actual page on npmjs.com, included for verification since that's the authoritative record of the account.

check_maintainer_blast_radius