tailscale/tailscale · warning

usage: tailscale ssh [user@]<host>

Error message

usage: tailscale ssh [user@]<host>

What it means

runSSH requires at least one positional target argument. With len(args) == 0 it returns a usage error immediately — no connection or name resolution is attempted. The accepted form is [user@]host, with extra args forwarded to ssh itself.

Source

Thrown at cmd/tailscale/cli/ssh.go:55

The 'tailscale ssh' wrapper adds a few things:

* It resolves the destination server name in its arguments using MagicDNS,
  even if --accept-dns=false.
* It works in userspace-networking mode, by supplying a ProxyCommand to the
  system 'ssh' command that connects via a pipe through tailscaled.
* It automatically checks the destination server's SSH host key against the
  node's SSH host key as advertised via the Tailscale coordination server.
`),
	Exec: runSSH,
}

func runSSH(ctx context.Context, args []string) error {
	if runtime.GOOS == "darwin" && version.IsMacAppStore() && !envknob.UseWIPCode() {
		return errors.New("The 'tailscale ssh' subcommand is not available on macOS builds distributed through the App Store or TestFlight.\nInstall the Standalone variant of Tailscale (download it from https://pkgs.tailscale.com), or use the regular 'ssh' client instead.")
	}
	if len(args) == 0 {
		return errors.New("usage: tailscale ssh [user@]<host>")
	}
	arg, argRest := args[0], args[1:]
	username, host, ok := strings.Cut(arg, "@")
	if !ok {
		host = arg
		username = ""
	}

	st, err := localClient.Status(ctx)
	if err != nil {
		return err
	}

	prefs, err := localClient.GetPrefs(ctx)
	if err != nil {
		return err
	}

View on GitHub (pinned to cfe32b8be6)

Solutions

1. Pass a target: `tailscale ssh user@host` (user@ is optional)
2. Guard variables in scripts: `: "${DEST:?destination required}"` before the call

Example fix

// before
$ tailscale ssh
usage: tailscale ssh [user@]<host>

// after
$ tailscale ssh admin@server

if dest == "" {
	return errors.New("tailscale ssh requires [user@]<host>")
}

When it happens

Trigger: `tailscale ssh` with no arguments; a script interpolating an empty destination variable (`tailscale ssh "${DEST}"`). The macOS App Store check runs first, so on those builds you'd see the platform error instead.

Common situations: Empty variables in automation; forgetting the destination after `tailscale ssh`; shell functions that conditionally append the host.

Related errors

• unexpected arguments
• expected at least one argument
• expected at least one argument after method
• expected exactly one integer argument
• unexpected arguments

AI-assisted analysis of tailscale/tailscale@cfe32b8be6 (2026-08-15). Data as JSON: /api/errors/6cc6e7d1cb3d5fc5. Report an issue: GitHub.