pnpm install @modelcontextprotocol/client not working

[JeanKouss]

Describe the bug
Trying to install the client with pnpm install @modelcontextprotocol/client zod fail with the following error :

ERR_PNPM_FETCH_404  GET https://registry.npmjs.org/@modelcontextprotocol%2Fclient: Not Found - 404

This error happened while installing a direct dependency of G:\path\to\project

@modelcontextprotocol/client is not in the npm registry, or you have no permission to fetch it.

No authorization header was set for the request.
Progress: resolved 16, reused 16, downloaded 0, added 0

To Reproduce
Steps to reproduce the behavior:

1. run pnpm install @modelcontextprotocol/client zod (command in readme)

Expected behavior
The package should be installed

[louis-cherik-getcaas]

Same while using NPM :

npm error code E404
npm error 404 Not Found - GET https://registry.npmjs.org/@modelcontextprotocol%2fserver - Not found
npm error 404
npm error 404 '@modelcontextprotocol/server@*' is not in this registry.
npm error 404
npm error 404 Note that you can also install from a
npm error 404 tarball, folder, http url, or git url.
npm error A complete log of this run can be found in: C:\Users\Louis\AppData\Local\npm-cache_logs\2026-01-20T13_54_40_134Z-debug-0.log