Two different pairing flows, both short: a 6-digit code for the watch, a copy-paste token for the desktop companion.
Sidecar → Settings → ⌚ Pair a watch → Get pairing code. It shows a 6-digit code, valid 5 minutes, that works once.
Open Tabby Watch → tap "⌚ Pair with Tabatha" (or "⌚ Re-pair watch" if you've paired before) → enter the 6 digits. It shows "Pairing…" then "Paired ✓."
"Code invalid or expired — mint a fresh one on your phone" just means the 5 minutes ran out, or it was already used — get a new code and try again.
Tabby Desk's tray menu → 🔗 Pair Extension (copy token) copies a pairing token to your clipboard.
Extension Settings → 🖥️ Desktop Activity → Companion Pairing → paste it into Paste pairing token → Save & Pair. You'll see "✓ Token saved — reconnecting to the companion."
No — it's a security-hardening step, not a hard requirement. An unpaired companion still connects in open mode; pair it if you want the link authenticated.