# Local Dev

Install, build and run the Inspector locally, and place a dependency correctly.

- Repository: https://github.com/modelcontextprotocol/inspector (11208 stars)
- Category: Git and review
- License: see repository
- Last updated: 2026-10-29
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add modelcontextprotocol/inspector --skill local-dev -g -a claude-code -y`
Codex: `npx skills add modelcontextprotocol/inspector --skill local-dev -g -a codex -y`
Cursor: `npx skills add modelcontextprotocol/inspector --skill local-dev -g -a cursor -y`
Gemini CLI: `npx skills add modelcontextprotocol/inspector --skill local-dev -g -a gemini-cli -y`

## Description

Install, build and run the Inspector locally, and place a dependency correctly. Use when starting the web, cli, tui or launcher client; when asking whether a build or rebuild is needed before a run script works; when an install, an @inspector/core import or a client bundle fails at run time; when adding or bumping a dependency and choosing which package.json declares it; or when a bundler external, a version skew or a git worktree is the suspect.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Local development

The **rules** a reviewer cites (TypeScript, Mantine/React, testing, the gate)
stay in [`AGENTS.md`](../../../AGENTS.md). This skill is how to get the thing
running and where a package goes.

## Install

Requires Node `>=22.19.0`.

```sh
npm install     # at the REPO ROOT
```

v2 is **not** an npm workspace, each client under `clients/*` keeps its own
`package.json` and `node_modules`. A single root `npm install` is still all you
need: the root `postinstall` (`scripts/install-clients.mjs`) cascades
`npm install` into `clients/web`, `clients/cli`, `clients/mcpdo`,
`clients/tui`, and `clients/launcher`.

- **Fresh clone:** `npm install` at the root.
- **After a pull that changes a client's dependencies:** re-run `npm install` at
  the root to re-sync every client.

The cascade is dev-only, it exits early when the package is installed under
`node_modules`, and a consumer never needs it because the tarball ships
**prebuilt** artifacts (each client's `build/`, plus `clients/web/dist` and
`clients/web/static`) rather than sources to compile. Set
`INSPECTOR_SKIP_CLIENT_INSTALL=1` to skip it. The `files` allowlist itself is
[`docs/publishing.md`](../../../docs/publishing.md).

⚠️ **In a git worktree, do a real `npm install`.** A symlinked `node_modules`
passes lint, tests and coverage, then fails every Storybook story file on Vite's
`fs.allow`.

## Running

For day-to-day **web** iteration, run Vite directly, fast HMR, no launcher
build needed:

```sh
cd clients/web && npm run dev
```

The launcher-driven scripts run the **built** launcher, so `npm run build`
first:

```sh
npm run build        # web → cli → mcpdo → tui → launcher
npm run web          # prod web launcher against clients/web/dist
npm run web:dev      # web launcher in --dev mode (Vite)
```

The rest: https://github.com/modelcontextprotocol/inspector/blob/HEAD/.claude/skills/local-dev/SKILL.md