Does the options mirror really buy calls/puts automatically?

Saw it open an ATM put next to a short. Is that automatic?

Yep — the options mirror is built in. When the bot goes long it buys ATM calls; when it goes short it buys ATM puts, nearest expiry, with a liquidity check on the spread. When the stock leg closes for any reason, the matching options close too. You set the contracts-per-trade in settings.