# Publishing The root `@modelcontextprotocol/inspector` package ships as **one tarball with a single version number** — no separate `-web` / `-cli` / `-tui` / `-core` packages. `npm run build` builds every client, then `prepack` runs before `npm publish`. Runtime dependencies are declared on the root `package.json`; client builds bundle `@inspector/core` and externalize npm packages resolved from the root install. ## What ships, and the packaging invariants The root `package.json` `"files"` allowlist is the source of truth for the tarball. A few non-obvious entries exist because they are read **at runtime** or were silently dropped by npm's packlist — do not remove them without re-running `npm run pack:verify`: - **No source maps.** The client bundlers set `sourcemap: false` (`clients/{cli,tui}/tsup.config.ts`, `clients/web/tsup.runner.config.ts`); Vite and the launcher's `tsc` already emit none. Maps are ~half the unpacked size and aren't needed at runtime — debug via `npm run dev` on the source. - **`clients/web/build` ships via `clients/web/.npmignore`.** `clients/web/.gitignore` lists `build/`, and npm's packlist honors that nested `.gitignore` over the root `"files"` allowlist — so the prod web-server runner was silently missing from the tarball while `clients/web/dist` slipped through (its `.gitignore` only lists `dist-ssr`). `clients/web/.npmignore` overrides the `.gitignore` for publishing so both `build/` (runner) and `dist/` (SPA) ship. The other clients don't need this — none ship a nested `.gitignore`. - **`clients/web/static` ships the MCP Apps sandbox proxy.** `clients/web/static/sandbox_proxy.html` is a committed source file (not a build artifact), read from disk at runtime by `clients/web/server/sandbox-controller.ts` as `/../static/sandbox_proxy.html`. It was missing from the root `"files"` allowlist entirely, so every published build failed the Apps tab with **"Sandbox not loaded"** ([#1859](https://github.com/modelcontextprotocol/inspector/issues/1859)) while working fine in the repo. Because the path is resolved _relative to_ `clients/web/build`, the directory must ship at that exact location — `pack:verify` asserts the tarball entry, the installed-on-disk path, and (since [#2003](https://github.com/modelcontextprotocol/inspector/issues/2003)) that a widget actually *loads through* it on the installed bin. Presence and reachability are different properties: a rename with a stale reader ships a file that is there and unusable. - **A dependency that renders React is bundled, not externalized.** An externalized package resolves its own `react` from wherever npm placed **it** in the consumer's tree, which is not necessarily where the bundle resolves ours — npm places a package beside a React satisfying _its_ peer range, and those ranges are looser than ours. `ink-form` and `ink-scroll-view` declare `">=18"`, so a project holding React 18 satisfies them and gets them hoisted while the Inspector's React 19 nests underneath: two React copies, and the TUI dies with `TypeError: Cannot read properties of null (reading 'useState')` the moment a tool test form or a scroll view mounts ([#1952](https://github.com/modelcontextprotocol/inspector/issues/1952)). Both are therefore inlined by `clients/tui/tsup.config.ts` and are **not** root dependencies: the tarball ships their code inside `clients/tui/build/index.js` rather than having consumers install them. Bundling also pins their transitive deps to what this repo's install resolved (notably `ink-select-input@6` via `overrides`, which npm ignores for a package installed as a dependency). **`ink` is the one exception, on cost:** bundling it works but adds ~1.4 MB (`react-reconciler` and `yoga-layout` come along, plus a `createRequire` banner for the inlined CJS), so it stays external — _not_ because its `">=19"` peer makes it safe, which it does not. What keeps that tolerable is the root `react` range: `"^19.0.0"` is deliberately open to the whole major so npm can dedupe our React with whatever React 19 a consumer pins, leaving an external `ink` on the same copy the bundle uses. **Narrowing that range reopens the bug for the renderer itself** — `clients/tui/__tests__/tsupConfig.test.ts` pins it to `ink`'s peer floor, and guards the rest of the split; see the [TUI README](../clients/tui/README.md#bundling-react-rendering-dependencies-must-be-inlined-1952). - **A single version number, read from the root `package.json`.** The Inspector ships as one package with one version, so only the **root** `package.json` carries a `version` — the four `clients/*/package.json`s deliberately have none. Every Node client (CLI, TUI, and the web backend) resolves the version through the shared `readInspectorVersion()` reader in `core/node/version.ts`, which walks up to the root manifest (always present in the tarball). No client `package.json` is read at runtime, so none needs to ship. The web **browser** can't read the filesystem; it gets its version from the backend via `GET /api/config` (see [#1639](https://github.com/modelcontextprotocol/inspector/issues/1639)). ## `npm run pack:verify` — publish smoke against the real tarball The `smoke:*` scripts run against the in-repo build tree, which is **not** the published package. `npm run pack:verify` (`scripts/pack-and-verify.mjs`) closes that gap: it builds, `npm pack`s the publishable tarball (asserting no source maps ship and that the runtime-required files are present), installs the tarball into a **clean throwaway consumer** — a fresh temp directory where it runs a real `npm install ` (pulls runtime deps, runs `postinstall`), exactly as `npx @modelcontextprotocol/inspector` would — and drives the installed `mcp-inspector` bin end to end: `--help` dispatch, a real `--cli tools/list` over stdio, a prod `--web` boot that must serve `/` from the shipped `dist`, and — riding that same boot — an **MCP App rendered in headless Chromium** through the shipped sandbox proxy, connect → open app → `data-app-status="ready"` ([#2003](https://github.com/modelcontextprotocol/inspector/issues/2003)). That last step shares its flow with `smoke:web:app` via `scripts/lib/mcp-app-flow.mjs` rather than copying it, since the deep-link shape is the part that rots silently; the *client* comes from the install while the App test server stays a repo fixture. It catches "works in `--dev`, breaks under `npx …`" path/packaging failures. It requires network access (the install pulls deps), so it is a local / release check, **not** part of the fast `validate` loop or of `local:gate`. ## Cutting a release The step-by-step procedure — bump on `v2/main` first, merge the milestone into `main`, tag `origin/main` with a bare `x.y.z`, then draft the GitHub Release — lives in the [`release` skill](../.claude/skills/release/SKILL.md), so there is exactly one copy of it. Invoke it as `/release`, or just read the file. The short version: publishing is automated by two release-gated jobs in [`.github/workflows/main.yml`](../.github/workflows/main.yml), both `needs: [build, coverage]`, so a release cannot publish with either the build job or the coverage gate red. ## Docker The container image and everything about running it — ports, volumes, where secrets go — is in [Running the Inspector in Docker](./docker.md).