> ## Documentation Index
> Fetch the complete documentation index at: https://learn.workflow.dog/llms.txt
> Use this file to discover all available pages before exploring further.

# Loop Workflow

> Run a callable workflow once for each item in a list.

**Loop Workflow** sends every payload to the selected workflow and collects the
returned values in the same order.

## Inputs

| Input                 | Type     | Required | Description                                      |
| --------------------- | -------- | -------- | ------------------------------------------------ |
| **Selected Workflow** | Workflow | Yes      | Callable workflow to run for each item.          |
| **Payloads**          | List     | No       | Items to process, up to 1,000. Defaults to `[]`. |

## Output

| Output      | Type | Description                                      |
| ----------- | ---- | ------------------------------------------------ |
| **Results** | List | One child result per payload, in matching order. |

Each item becomes **Data In** in the child workflow. A child run without
**Return Data** contributes `null` to the result list.

<Note>
  Iterations run sequentially, not in parallel. This preserves order but means
  total runtime grows with the number and duration of child runs.
</Note>

<Warning>
  If any child run fails, this action fails and does not return partial results.
  Recursive workflow calls are also rate-limited to prevent infinite loops.
</Warning>