What is MCP and how does flexx use it?

MCP (Model Context Protocol) is an open standard that lets AI agents interact with external tools. flexx turns your machine into an MCP server — AI agents like Cursor, Claude, and ChatGPT can read files, run commands, and edit code on your machine through the relay.

Which AI tools work with flexx?

Any tool that supports the Model Context Protocol (MCP) works with flexx. This includes Cursor, Claude Desktop, ChatGPT with MCP plugins, OpenAI Codex, and any custom MCP client.

Can I use flexx without installing anything?

Yes — for Memory. Create a free account and connect any MCP client; the memory tools need no install and no machine. Remote tools (files, shell, screenshots, tunnels) only become available after you install the flexx CLI on a machine and connect it.

Is my machine exposed to the internet?

No. Your machine only makes outbound WebSocket connections to the relay. Zero inbound ports are opened. The relay mediates all communication between AI agents and your machine.

How do I connect Cursor to my machine via MCP?

Install flexx (curl -fsSL https://cli.flexx.dev/install.sh | sh), run 'flexx setup', then add the MCP server URL https://relay.flexx.dev/v1/mcp in Cursor Settings → MCP → Add Server. OAuth authentication is handled automatically.

Yes. The free tier includes unlimited remotes, unlimited MCP tools, SSH access, and localhost tunneling. Managed and team tiers with additional features are coming soon.

CLI Reference

Complete reference for all flexx CLI commands. Install, authenticate, connect, and manage remotes from the terminal.

Global flags

flexx [command] --help    Show help for any command

Commands

`flexx setup`

Authenticate, register this machine, and print MCP config. Does not start the daemon.

flexx setup

After setup, start a connection:

flexx service install   # always-on (recommended)
flexx connect           # foreground
flexx connect --daemon  # background

`flexx connect`

Start the daemon and connect to the relay server.

flexx connect           # Foreground
flexx connect --daemon  # Background (detached)

Flag	Description
`--daemon`	Run in background, write PID to `~/.flexx/flexx.pid`

`flexx auth`

Manage authentication.

flexx auth login              # Browser login or API key prompt
flexx auth login --api-key=…  # Non-interactive
flexx auth logout             # Remove stored credentials
flexx auth whoami             # Show current auth status

API keys start with flexx_ and can be generated from Dashboard → Settings → API Keys.

`flexx remote`

Manage remote machines.

flexx remote init          # Register this machine
flexx remote list          # List all remotes (alias: ls)
flexx remote unregister    # Delete this remote (with confirmation)

flexx remote init also configures the SSH ProxyCommand for flexx-* hosts automatically.

`flexx ssh`

Show SSH connection info for a remote.

flexx ssh my-server

This displays the SSH command. To connect directly:

ssh flexx-my-server

The SSH ProxyCommand is auto-configured by flexx remote init.

`flexx mcp`

MCP helpers.

flexx mcp config    # Print MCP JSON configuration

Outputs the JSON block with your relay URL and API key, ready to paste into Cursor, Claude Desktop, or any MCP client.

`flexx service`

Manage flexx as a user service (starts on login).

flexx service install     # Install service (Linux / macOS / Windows)
flexx service uninstall   # Remove service
flexx service status      # Show service status
flexx service start       # Start the service
flexx service stop        # Stop the service
flexx service restart     # Restart the service
flexx service logs        # Stream logs

Platform	Mechanism
Linux	systemd user unit
macOS	LaunchAgent
Windows	Task Scheduler (user-level, no admin)

`flexx status`

Show daemon PID, running state, and remote connection status.

flexx status

`flexx update`

Self-update to the latest version from cli.flexx.dev.

flexx update

`flexx version`

Print version and build commit.

flexx version

Configuration files

File	Purpose
`~/.flexx/config.json`	API URL and API key
`~/.flexx/remote.json`	Remote ID, relay URL, secret, workspace path
`~/.flexx/flexx.pid`	PID of background daemon
`~/.flexx/daemon.log`	Daemon log file

CLI Reference

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