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

# Loops

> Iterate over a set of values with the loop_sequential task type

## `type: loop_sequential`

Runs a set of nested `tasks` once for each value in `values`.

| Component | Description                                                                 | Type     |
| --------- | --------------------------------------------------------------------------- | -------- |
| values    | Values to iterate over for each `task` in the current task's `tasks` array. | required |
| tasks     | Defines the tasks to execute for each `value`.                              | required |

`values` are accessed within the `tasks` of the `loop_sequential` task as
`<name>.value`, where `<name>` is the name of the task. A sample partial config
is shown below:

```yaml theme={null}
tasks:
  - name: loop_through_animals
    type: loop_sequential
    values: ["whale", "dolphin", "shark"]
    tasks:
      - name: get_number_of_animals
        type: agent
        agent_ref: default
        prompt: |
          Get the number of {{ loop_through_animals.value }}s in the ocean.
```

## Seeding `values` with query results

The `values` can be seeded with the output from a previous `execute_sql` step,
as follows:

```yaml theme={null}
  - name: get_all_animals
    type: execute_sql
    sql_file: outputs/cache/get_all_animals.sql
    database: local

  # Loop over every animal
  - name: loop_through_animals
    type: loop_sequential
    values: "{{ get_all_animals.animal_name }}"  # `animal_name` is the column name to loop over
    tasks:
      ...
```

## Formatting loop outputs

Loops are often combined with the [`type: formatter`](/docs/guide/build/automations/task-types#type-formatter)
task, which can loop through the resulting outputs and form them into a single
string. The output from a `loop_sequential` is an array of dictionaries for each
`value`, where the keys for each element of each dictionary are named according
to the task's `name` field. These can be accessed with Jinja by looping through
the `{{ <loop_name> }}` variable (`{{ loop_through_animals }}` above).

An example of this behavior is shown below:

```yaml theme={null}
- name: format_animal_report
  type: formatter
  template: |
    {% for animal in loop_through_animals %}
    {{ animal.get_number_of_animals }}
    {% endfor %}
```

## Concurrency

Concurrency can be added to the loop by using the `concurrency` key, with the
value specifying the number of concurrent threads to use.

```yaml theme={null}
- name: loop_through_animals
  type: loop_sequential
  concurrency: 5
  values: ...
  tasks: ...
```

## Next steps

<CardGroup cols={2}>
  <Card title="Task types" icon="diagram-subtask" href="/docs/guide/build/automations/task-types">
    The tasks you run inside a loop
  </Card>

  <Card title="Variables" icon="brackets-curly" href="/docs/guide/build/automations/variables">
    Parameterize an Automation
  </Card>
</CardGroup>