# Antfu Node Modules Inspector Node Modules Inspector > node-modules-inspector - Skill: `tomevault-io/antfu-node-modules-inspector-node-modules-inspector` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/antfu-node-modules-inspector-node-modules-inspector` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/antfu-node-modules-inspector-node-modules-inspector/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/antfu-node-modules-inspector-node-modules-inspector --- # node-modules-inspector `node-modules-inspector` is a CLI + MCP server that inspects the installed `node_modules` of the current project and produces structured reports. Three reports, same underlying analysis pipeline: | Report | Answers | |---|---| | `duplicates` | Which packages are installed in multiple versions? | | `sizes` | Which packages take up the most disk space? | | `maintainers` | Which consumers have dep-upgrade opportunities or publint issues, grouped by package and author? | Reports run against the real on-disk `node_modules` — no registry calls are required for the basic shape; npm metadata is fetched only to enrich the maintainers report (gated by config). Works with pnpm, npm, and bun. The default `npx node-modules-inspector` (with no subcommand) opens a Vue web UI for humans; agents should use the `report` and `mcp` subcommands below. ## When to reach for this Trigger on any of: - "audit my dependencies", "find duplicate packages", "node_modules cleanup" - "what's taking up disk space in node_modules" - "which deps are outdated" / "what dep-upgrade opportunities are there" - "show me publint issues across my deps" - "who maintains my dependencies" Don't reach for it for: registry-only questions (use `fast-npm-meta`), bundle-size analysis of a single package (use a bundler-specific tool), security audits (use `npm audit` / `osv-scanner`). ## CLI mode All subcommands share these options: - `--root ` — project root (default: cwd) - `--config ` — config file (default: `node-modules-inspector.config.{ts,js,json}`) - `--depth ` — max dependency depth to traverse (default: `8`) - `--json` — emit JSON to stdout; pretty ANSI table otherwise Progress logs always go to stderr, so `... --json` is pipe-safe. ### duplicates ```sh npx node-modules-inspector report duplicates --json ``` Options: - `--min-versions ` — only include packages installed at this many versions or more (default: `2`) - `--limit ` — cap result count Output shape: ```json [ { "name": "@typescript-eslint/scope-manager", "versions": ["8.56.1", "8.59.1", "8.59.2", "8.59.4"], "specs": ["@typescript-eslint/scope-manager@8.56.1", "..."] } ] ``` Versions are sorted ascending by semver. Entries are sorted by version-count descending. Use this to find dedupe targets — `pnpm dedupe` / `npm dedupe` resolves these where ranges overlap. ### sizes ```sh npx node-modules-inspector report sizes --json --limit 20 ``` Options: - `--limit ` — cap result count (default: `50`) - `--include-workspace` — include workspace packages (default: excluded; they have no meaningful install size) Output shape: ```json [ { "spec": "typescript@6.0.3", "name": "typescript", "version": "6.0.3", "workspace": false, "bytes": 24346827, "categories": { "js": { "bytes": 15344521, "count": 200 }, "dts": { "bytes": 7002306, "count": 150 } } } ] ``` `categories` keys come from a fixed set: `js`, `ts`, `dts`, `json`, `bin`, `wasm`, `map`, `image`, `css`, `html`, `comp`, `doc`, `test`, `flow`, `other`. Entries are sorted by `bytes` descending. ### maintainers ```sh npx node-modules-inspector report maintainers --json ``` Options: - `--sort ` — sort by consumer depth, max migration ratio, or latest release time (default: `depth`) - `--author ` — filter to consumers maintained by this author; repeatable - `--no-publint` — exclude publint findings - `--no-latest-only` — include consumer packages that are not on their latest major - `--limit ` — cap result count Output shape: ```json [ { "consumer": { "spec": "rollup-plugin-esbuild@6.2.1", "name": "rollup-plugin-esbuild", "version": "6.2.1", "depth": 1 }, "authors": [{ "type": "github", "github": "egoist", "avatar": "..." }], "items": [ { "kind": "dep-upgrade", "depName": "unplugin-utils", "depType": "prod", "declaredRange": "^0.2.4", "rawRange": "catalog:deps", "catalogName": "deps", "installedHighestVersion": "0.3.1", "installedHighestSpec": "unplugin-utils@0.3.1", "installedVersions": ["0.2.4", "0.3.1"], "migratedCount": 10, "totalCount": 11, "migrationRatio": 0.909 }, { "kind": "publint", "messages": [/* publint Message objects */], "counts": { "error": 0, "warning": 1, "suggestion": 2 } } ], "maxMigrationRatio": 0.909, "latestReleasedAt": 1739000000000 } ] ``` How to read this: - A `dep-upgrade` item means: this consumer declares `depName` at `declaredRange`, but there's a newer installed version (`installedHighestVersion`) that the range does not satisfy. `migrationRatio` is the fraction of consumers in the same cohort that already migrated — a high ratio (e.g. 0.9) means most other consumers already moved on, so this one is lagging. - `rawRange` differs from `declaredRange` only when the consumer used a pnpm catalog reference (`catalog:deps`); `declaredRange` is the resolved range. - A `publint` item carries the raw publint messages, partitioned by severity in `counts`. - `authors` come from the consumer's `package.json` author/maintainers fields, with GitHub-handle detection. Publint findings only appear when `pkg.resolved.publint` was populated. Enable that by adding `publint: true` to `node-modules-inspector.config.ts` (or by using the project's web UI which runs publint async). ## MCP mode ```sh npx node-modules-inspector mcp ``` Starts an MCP stdio server. Exposes three tools, identical surface to the CLI: - `nmi:report-duplicates` - `nmi:report-sizes` - `nmi:report-maintainers` When configured in an MCP client (e.g. Claude Code) under server name `node-modules-inspector`, address them as `node-modules-inspector:nmi:report-duplicates`, etc. Tool input schemas mirror the CLI options. Tool output is JSON in the exact shape shown above for each report. Prefer MCP when: - Multiple queries are expected in one session — the dependency tree is read once and cached across tool calls. - The agent needs structured output schemas to drive validation. Prefer the CLI (`report ... --json`) when shell-pipelining (`jq`, redirect, etc.) is more convenient. ## Flags the agent should know - The first run reads `node_modules` end-to-end and caches npm metadata on disk (under `~/.node-modules-inspector` or similar). Subsequent runs are much faster. - Workspace packages are excluded from `sizes` by default — pass `--include-workspace` if you actually want them. - `--depth 8` is enough for almost all real projects. Increase only if the user explicitly asks about deeply-nested transitive dependencies. - For very large monorepos, running against a single workspace package via `--root packages/` is faster than the whole repo. ## Failure modes - "No package manager detected" — the project has no `node_modules` directory, or none of pnpm/npm/bun lockfiles. Suggest the user run install first. - Empty `duplicates` result — fine, it means everything is deduped (mention `pnpm dedupe` etc. only if user wants to verify). - Empty `maintainers` result — usually means there are no dep-upgrade opportunities AND `publint: true` is not set in the config; if the user expected publint output, point them at the config. ## Web UI (skip for agent tasks) `npx node-modules-inspector` (no subcommand) starts a Vue dev server on port `9999` with a full visual explorer (graph view, filters, multi-version compare, maintainer-action dashboard). It's for humans; don't suggest it for an agent task. The `report` CLI and `mcp` server above cover the same data programmatically. `npx node-modules-inspector build` produces a static SPA of the analysis into `dist/__node-modules-inspector/` — useful for CI artifacts but not for agent consumption. --- > Source: [antfu/node-modules-inspector](https://github.com/antfu/node-modules-inspector) — distributed by [TomeVault](https://tomevault.io).