Leszczynskikarol MCP MCP Server

Connect Leszczynskikarol MCP to Claude, Cursor or any other MCP client and it stops being a tab you switch to. Self-hosted MCP server for Claude.ai. Give Claude direct access to AWS, SSH, local shell, GitHub, PostgreSQL and PM2 — without Claude Code subscription. Your keys never leave your machine. The leszczynskikarol mcp mcp server is what makes that connection.

What the server does

All 10 tools live in your Claude.ai sidebar - no Desktop install, no separate client, just a custom connector.

A small Node.js MCP server you run on your own machine (laptop, desktop, VPS) and connect to Claude.ai (or any MCP client) as a Custom Connector. It exposes a configurable set of tools that let Claude do real work on your infrastructure:

• ✅ No Claude Code subscription needed — works with regular Claude.ai (web)
• ✅ OAuth 2.1 with PKCE — proper Claude.ai integration, not a hacky workaround
• ✅ Your keys stay yours — SSH keys, GitHub PATs, AWS creds never leave your machine
• ✅ Self-hostable — Windows, Linux, Mac, anything that runs Node 18+
• ✅ Configurable via JSON — add a new server or new key without touching code
• ✅ One file to read — no framework magic, no hidden config

Available tools

The toolset is worth reading before you wire it up, because it tells you what the integration is really for:

• aws_cli — Run any aws using your local AWS CLI profile
• ssh_exec — SSH into any host using a key defined in hosts.json
• local_exec — Run any shell command on the local machine (cmd.exe on Windows, /bin/sh elsewhere)
• write_file — Write text content to a local file (overwrite or append). Full UTF-8, no shell quoting issues — preferred over local_exec for any non-trivial file
• github_api — Make REST API requests to GitHub using your Personal Access Token
• postgres_query — Run psql queries via SSH (sudo -u postgres) on a host from hosts.json
• pm2_status — Show pm2 list and optional logs on a remote server
• sftp_download — Stream a file from a remote host to the local filesystem (uses the persistent SSH pool). Essential when working from Claude.ai web — the cloud
• sftp_upload — Stream a local file to a remote host. Optional POSIX mode flag (e.g. 0755). Parent dir must exist on remote
• book_split — Split a large text file into ~3000-word chunks
• book_chunk — Read one chunk from a directory created by book_split
• book_note — Manage JSON notes for iterative work on long documents

Credentials and setup notes

Configuration is passed through the environment: MCP_BASE_URL, GITHUB_TOKEN. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.

• Node.js 18+ (tested on 22, 24, 25) - SSH .pem keys locally (for hosts you want to control) - AWS CLI configured locally (aws configure) — only if you use the aws_cli tool - A public HTTPS endpoint — only if you want to expose this to Claude.ai ---

Installation

Because this one is hosted, setup is mostly authentication — you point your client at the endpoint and approve access. Nothing runs on your machine, so there is no runtime to keep patched.

Where it fits

Among the developer tooling options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Leszczynskikarol MCP's toolset — aws_cli, ssh_exec, local_exec and 9 more — is a fair guide to whether it matches your workflow. It is maintained by leszczynskikarol; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

Worth knowing first

• Your data travels to the provider's service, so the usual questions apply about what you send and what they retain.
• With 12 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Leszczynskikarol MCP.
• Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
• Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.