# Runner.register

```python
def Runner.register(task: type[Task]) -> None
```

Register a task class with a reusable runner definition.

Use `register` when you want to build a runner incrementally instead of passing all task classes to the [`Runner`](/docs/api-reference/python/tilebox.workflows/Runner) constructor.

## Parameters

**task**

`type[Task]`

required: true

Task class that this runner can execute.

## Returns

`None`

```python title="Python"
from tilebox.workflows import Runner

from my_workflow.tasks import MyRootTask, MySubtask

runner = Runner()
runner.register(MyRootTask)
runner.register(MySubtask)
```