Introduction to flexx

What is flexx?

flexx is a single binary that turns any machine into a remote that AI agents can access via MCP (Model Context Protocol).

Install it, run flexx setup, then flexx connect (or flexx service install), and your machine is accessible to Cursor, Claude Desktop, ChatGPT, OpenAI Codex, or any MCP-compatible agent — no VPN, no port forwarding, no firewall rules.

How it works

Your Machine ──(outbound WebSocket)──▶ Relay ◀── AI Agent (MCP/SSH)

1. flexx runs on your machine and connects outbound to the relay server
2. AI agents connect to the relay via MCP or SSH
3. The relay bridges requests between the agent and your machine
4. Your machine never opens inbound ports — zero attack surface

Quick start

# Install flexx CLI
curl -fsSL https://cli.flexx.dev/install.sh | sh

# Authenticate and register this machine (does not start the daemon)
flexx setup

# Connect to the relay
flexx connect
# or always-on:
# flexx service install

After setup, you'll get an MCP configuration block to paste into your AI agent's settings. Or sign in to the dashboard to see your MCP URL and step-by-step instructions for Cursor, Claude, ChatGPT, and more.

Key features

• MCP tools for AI agents — file operations, shell execution, screenshots, code search, and more
• SSH remote access — ssh flexx-myserver works like any SSH host
• Localhost tunneling — expose dev servers publicly with a single command
• Auto-discovery — detects installed tools (ripgrep, Docker, Chrome, GPUs)
• Workspace safety — path scoping, command blocklist, file size limits
• OAuth 2.1 authentication — secure consent-based access for AI agents
• Self-update — flexx update pulls the latest version
• Cross-platform — macOS, Linux, Windows (amd64 and arm64)

Supported AI tools

flexx works with any MCP-compatible AI tool, including:

• Cursor — add the MCP server URL in Settings → MCP
• Claude Desktop — add to ~/.claude/mcp_servers.json
• ChatGPT — use the MCP endpoint with OAuth authentication
• OpenAI Codex — connect via standard MCP configuration
• Any MCP client — standard Model Context Protocol endpoint

Next steps