---
title: Installation
description: Install the WebMCP Kit plugin in Claude Code or Codex, and set up a browser that can run WebMCP tools.
---


## Prerequisites

- **Claude Code 2.1.220 or newer** (`claude --version`) — or Codex.
- **Your website's repo**, cloned locally, with a dev server you can run.
- **A WebMCP-capable browser** for the verification step — see [Browser setup](#browser-setup) below. Not needed to install the plugin.

## Claude Code

Inside a Claude Code session:

```
/plugin marketplace add nekuda-ai/webmcp-kit
/plugin install webmcp-kit@nekuda
```

Or from your terminal — same result:

```sh
claude plugin marketplace add nekuda-ai/webmcp-kit
claude plugin install webmcp-kit@nekuda
```

Confirm it worked:

```sh
claude plugin details webmcp-kit@nekuda
```

Expect `Skills (2): implement, verify`. The skills load as `/webmcp-kit:implement` and `/webmcp-kit:verify`.

## Codex

The plugin ships in the [Agent Plugins](https://agent-plugins.org/) open format, which Codex supports natively. In a Codex session:

1. Run `/plugins` to open the plugin directory.
2. Add `nekuda-ai/webmcp-kit` as a marketplace source.
3. Install `webmcp-kit`.

## Browser setup

WebMCP is a young standard, so the browser surface (`document.modelContext`) is behind a flag today. You only need it to *test* tools — visitors with unsupported browsers are unaffected, because the SDK quietly does nothing there.

Pick one:

- **Chrome 150+** — open `chrome://flags`, enable the WebMCP flag for localhost. This exposes `document.modelContext`.
- **Chrome 149** — exposes only the older `navigator.modelContext`; the SDK handles both.

Quick check in devtools:

```js
typeof document.modelContext   // "object" when WebMCP is active
```

## Updating

```
/plugin marketplace update
```