;
};
Runs a subgraph once for every item in a list.
Connect the body you want to repeat to the **Loop Body** output port. Inside
the loop, the current item is available in the configured item assign — read
it with an Assign Read node (or let Attribute nodes pick it up as the
subject, if it's a defdata struct).
Assigns are shared across iterations: whatever iteration N writes, iteration
N+1 sees. Handy for accumulating counters or per-item side effects.
### Configuration
* **Source list assign** — assigns key holding the list to iterate.
* **Current item assign** — the loop body reads the item from here.
* **Collect** — optional. One row per value you want out of the loop: name the
assign to collect into, and pick where the value comes from (same sources as
Flow Compose). Each named assign is emptied when the loop starts and gets one
entry appended per successful iteration, so the list is ready to use straight
after the loop — no accumulator to reset, and it stays correct when this loop
sits inside another one.
### Control flow
* *Halt branch* inside an iteration (e.g. from a Flow Guard) stops that
iteration but the loop continues with the next item.
* *Halt flow* (from a Flow Guard set to halt flow, or any unrecoverable
error) stops the whole run immediately.
### Tips
* Pair with Flow Filter first to narrow the list down — iterating a
filtered list is usually cheaper and clearer than guarding inside the
loop body.
## Ports