The engine command strip, explained
Every engine control lives in one place: the command strip at the top of the trading pages, Trade Desk, Accounts, Copy Rules and Risk Management. It is the same card on each of them: a state dot and the status word on the left, the buttons on the right. (There is also an optional Overview page your admin can switch on. Where it is on, it carries the same strip.) There are no engine controls anywhere else, so you never have to hunt for the off switch.
The four buttons
Start copying
The blue button. From the moment you press it, every leader fill places real orders on your follower accounts. If no copy group has a leader account configured, the start fails with a plain message telling you to pick a leader on the Copy Rules page. It will not start half-configured.
Stop
Copying stops immediately. Open positions stay open on every account. Nothing is closed. Stop is for "stop mirroring new fills", not for "get me flat". If you want flat, that is the next button.
Flatten all
The outlined red button. One click closes every open position (the leader's as well as the followers') at market, and pauses copying until you press Resume. It is disabled when nothing is open, so you can read its state as "is anything at risk right now". Full detail in the Flatten all kill switch.
Resume
Re-enables every group, including a group that stopped itself because its leader hit a risk limit. After a full flatten, Resume re-opens nothing: the leader is flat, so there is nothing left to copy. The engine reconciles from the broker's live book and waits for the next fill.
One click by default
All four buttons act on a single click. There is no arming stage and no typed confirmation. If you want a second look before the big ones, the Risk Management page has three opt-in switches: Ask before Flatten all, Ask before Start copying, and Ask before Stop. They are off by default and apply in that browser only.
Using Flatten all, or the copier stopping for any reason, also raises an alert: a toast, and an e-mail or Telegram message if you have those on. That is deliberate: an engine that stops while you are away from the screen is exactly the thing you would want to be told about. See notifications and alerts.
Quick answers
Does Stop close my positions?
No. Stop only stops copying. Every open position stays exactly where it is, on every account. Use Flatten all when you want everything closed.
Why is Flatten all greyed out?
No account has an open position, so there is nothing to flatten. The button enables the moment anything is open.
Can Resume accidentally re-open what I just flattened?
No. After a full flatten the leader is flat, and followers only mirror the leader. Resume re-enables copying; it does not place orders on its own.