pair

Pair with a discovered device or direct IP.

Usage

connecto pair <TARGET>

Arguments

Options

Description

The pair command establishes SSH key-based authentication with a remote device:

1. Generates a new Ed25519 SSH key pair (or uses an existing key — see below)
2. Sends the public key to the target device
3. Displays a 6-digit verification code to compare with the listening device
4. Saves the private key to ~/.ssh/connecto_<device>
5. Updates ~/.ssh/config for easy ssh hostname access

Examples

Pair by Device Number

After running connecto scan:

connecto pair 0

Output:

  CONNECTO PAIRING

→ Connecting to 192.168.1.55:8099...
→ Using Ed25519 key (modern, secure, fast)

✓ Pairing successful!

→ Verification code: 627765 — confirm it matches on mydesktop

Key saved:
  • Private: /home/user/.ssh/connecto_mydesktop
  • Public:  /home/user/.ssh/connecto_mydesktop.pub

✓ Added to ~/.ssh/config as 'mydesktop'

You can now connect with:

  ssh mydesktop

The verification code is derived from the key you sent; the listener derives the same code from the key it received. If the listener runs with --verify, its operator compares the codes before approving — matching codes rule out a man-in-the-middle that swapped the key (see Security).

Pair by IP Address

Skip scanning and pair directly:

connecto pair 192.168.1.55:8099

Or with just the IP (uses default port 8099):

connecto pair 192.168.1.55

What gets created

SSH key pair

• Private key: ~/.ssh/connecto_<device>
• Public key: ~/.ssh/connecto_<device>.pub

<device> is the listener’s device name sanitized into a lowercase alias (e.g. My Desktop → my-desktop). Keys use Ed25519 by default (modern, secure, fast).

SSH config entry

An entry is added to ~/.ssh/config:

# Added by connecto
Host mydesktop
    HostName 192.168.1.55
    User john
    IdentityFile /home/user/.ssh/connecto_mydesktop

This allows simple ssh mydesktop without specifying user, IP, or key. The # Added by connecto marker identifies the entry as connecto-managed: commands like hosts, unpair, and update-ip only ever touch marked blocks, never your hand-written config.

Re-pairing

If you pair with a device that already has a connecto-managed entry:

1. The SSH config block is replaced in place
2. A new key exchange occurs; a freshly generated key overwrites the old key files

This is useful when:

• The remote machine was reinstalled
• You want to refresh the keys
• The IP address changed

Using existing keys

Instead of generating a new key for each pairing, you can use an existing SSH key.

One-time usage

connecto pair 0 --key ~/.ssh/id_ed25519

Both the private key and its .pub file must exist.

Set default key

Set a default key for all future pairings:

connecto config set-default-key ~/.ssh/id_ed25519

Now connecto pair and connecto sync will use this key automatically.

Clear default key

Return to generating new keys:

connecto config clear-default-key

Priority order

When pairing, Connecto looks for keys in this order:

1. --key flag (if specified)
2. Config default key (if set)
3. Generate new key (default behavior)

After pairing

Connect immediately:

ssh mydesktop

Or verify the pairing:

connecto test mydesktop

Exit status

pair exits non-zero when pairing fails (connection refused, rejected by the listener, invalid key, …), so it is safe to chain in scripts:

connecto pair 0 && ssh mydesktop