Editing copy rules while the copier runs
While the copier runs, the Copy Rules editor is read-only. The page dims, and a note explains why: "Stop copying to edit these settings — changes while the copier is running are not allowed." The API refuses the same way, with a 409: "The copier is running — stop it before changing your copy rules."
Why the lock exists
The engine reads your configuration once, when it starts. An edit made mid-run would either do nothing until the next restart — silently — or, worse, re-target accounts that already hold positions under the old rules. Neither is acceptable, so the honest answer is to refuse. Stop, edit, save, start again.
Locked settings include the leader account and leader instrument, follower sizing, Max, Rev, Cross Order, adding or deleting groups, and the "Never copy these instruments" list.
What still works live
Three things are deliberately allowed while the copier runs, because they change which rules are on, never the rules themselves:
- The Follow switch, per account, on the Trade Desk. Flip a follower off and it stops copying; its settings are remembered.
- Pause all / Resume all followers, also on the Trade Desk. The same switch, applied to everyone at once.
- Renaming a group on Copy Rules. Cosmetic, saves immediately.
Anything structural sent to the Follow-switch endpoint is refused outright: "Structural copy-rule edits go through the Copy Rules page — this endpoint only flips the Follow switches."
Quick answers
Why does my save return 409?
The copier started after the page loaded. Stop it from the engine command strip, save again, then start. The page pulls the lock state as soon as the save is refused.
Can I pause one follower without stopping everything?
Yes. The Follow switch on the Trade Desk works mid-session. It flips the rule off in place; sizing and settings survive.
Does stopping the copier close my positions?
Stopping halts copying; it is not a close. If you want positions closed as well, that is what Flatten all is for — see engine controls explained.