/synthex:cancel-loop/synthex:cancel-loop

#What it does, end-to-end

/synthex:cancel-loop/synthex:cancel-loop marks a running loop as cancelled. The cancel is polled at the iteration boundary by the looping command — a loop that's mid-iteration when you cancel it will finish that iteration's work, then exit cleanly on the next boundary check. Worst case: one iteration of latency before the loop stops.

The mutation is atomic: tmp file + mv -f rename, so concurrent reads from /synthex:list-loops/synthex:list-loops or another session's iteration boundary never see a half-written state.

The command is idempotent. Cancelling an already-cancelled (or completed, or max-iterations-reached, or crashed) loop is a no-op with a single confirmation line — never an error.

#Parameters

#Examples

#Cancel a single loop

/synthex:cancel-loop release-1
# → Cancelled loop "release-1" (was at iteration 12/30).

#Cancel a loop you've already cancelled (idempotent)

/synthex:cancel-loop release-1
# → Loop "release-1" is already cancelled — nothing to do.

#Cancel everything running in this project

/synthex:cancel-loop --all
# → Cancelled (3):
#     release-1            was at iter 12/30
#     review-check-7e1d    was at iter 4/10
#     team-plan-4c66       was at iter 6/15

If nothing is running:

/synthex:cancel-loop --all
# → No running loops to cancel.

#Refusal paths

• Neither loop_id nor --all supplied. Prints Usage: /synthex:cancel-loop <loop-id> | --all and exits non-zero.
• Both loop_id and --all supplied. Mutually exclusive; pick one.
• loop_id doesn't match an existing state file. Names the slug and suggests /synthex:list-loops/synthex:list-loops.

If .synthex/loops/ doesn't exist at all (no loop has ever run in this project), the command prints No loops in this project. and exits 0 — not a refusal.

#Cancellation timing

--loop-bearing commands check the state file's status at every iteration boundary (per FR-NL14 step 7). The cancel takes effect on that next read. Cancellation never interrupts an iteration that is currently executing — the worst-case latency is one iteration's worth of work before the loop exits.

For workflows where in-flight teammate work needs to be torn down on cancel (rare), the command's own teardown semantics handle it — /synthex:cancel-loop/synthex:cancel-loop only changes the loop counter contract; the inner workflow's cleanup behavior is unchanged.

#What it does not do

• Delete the state file. Terminal-status state files are archived later by any loop command that touches .synthex/loops/. The cancel leaves the file in place so you can read the iteration history (started_at, iteration, exit_reason) until then.
• Touch loops in .archive/. Archived loops are historical and immutable.
• Touch the Ralph plugin's state file. Cancel the Ralph loop through the Ralph plugin if you also have one configured. See Coexistence with Ralph Loop.
• Prompt the user. No AskUserQuestion — single deterministic mutation + confirmation line.

#See also

• Native looping — the full framework explainer.
• /synthex:loop/synthex:loop — start or resume a loop.
• /synthex:list-loops/synthex:list-loops — enumerate loops in the project.