zenvx-mcp

Secure self-hosted remote MCP server — Python (FastMCP, streamable HTTP) behind a Cloudflare Tunnel with bearer-token auth. Zero inbound ports.

Live endpoint: https://mcp.zenvx.in/mcp (Bearer token required)

Architecture

MCP client → Cloudflare (TLS + WAF) → cloudflared tunnel → 127.0.0.1:8765 → laptop

Tools

Tool	Description
ping	Health check
list_dir	List a directory under the sandbox root
read_file	Windowed text-file read (offset/limit)
write_file	Write or append UTF-8 files (logged)
run_shell	Full shell access — OFF unless MCP_ALLOW_SHELL=true; every call logged; 120s cap

Security model

1. Cloudflare Tunnel — outbound-only; no open inbound ports; TLS + DDoS protection free
2. Bearer token — every request must carry Authorization: Bearer <token> (openssl rand -hex 32)
3. Cloudflare Access (recommended) — Zero Trust policy at the edge, so a leaked token alone is useless
4. Sandbox root — file tools cannot escape MCP_FS_ROOT
5. Non-root systemd user — unit hardening: NoNewPrivileges, PrivateTmp, ProtectSystem

Repo layout

File	Purpose
server.py	MCP server (FastMCP + bearer-auth middleware)
requirements.txt	mcp SDK + uvicorn
cloudflared-config.yml	Tunnel ingress: mcp.zenvx.in → localhost:8765
zenvx-mcp.service	systemd unit
zenvx-mcp.env.example	Env template — copy to /etc/zenvx-mcp.env, chmod 600
SETUP.md	Full setup guide: venv → token → systemd → tunnel → Access → clients

Quick start

python3 -m venv .venv && .venv/bin/pip install -r requirements.txt
export MCP_AUTH_TOKEN=$(openssl rand -hex 32)
python server.py   # serves 127.0.0.1:8765/mcp — front it with cloudflared, never bind 0.0.0.0

Full instructions, Cloudflare Tunnel/Access steps, client configs (Claude Desktop, Notion MCP connector, MCP Inspector), and the Windows variant: SETUP.md