# Child Workflows - .NET SDK

> Start a Child Workflow Execution and set a Parent Close Policy using Temporal .NET SDK. Discover methods like ExecuteChildWorkflowAsync and manage Workflow behaviors.

This page shows how to do the following:

- [Start a Child Workflow Execution](#child-workflows)
- [Set a Parent Close Policy](#parent-close-policy)

## Start a Child Workflow Execution 

A [Child Workflow Execution](/child-workflows) is a Workflow Execution that is scheduled from within another Workflow using a Child Workflow API.

When using a Child Workflow API, Child Workflow related Events ([StartChildWorkflowExecutionInitiated](/references/events#startchildworkflowexecutioninitiated), [ChildWorkflowExecutionStarted](/references/events#childworkflowexecutionstarted), [ChildWorkflowExecutionCompleted](/references/events#childworkflowexecutioncompleted), etc...) are logged in the Workflow Execution Event History.

The [ChildWorkflowExecutionStarted](/references/events#childworkflowexecutionstarted) Event must be logged to the Event History before the Parent Workflow completes to ensure the Child Workflow has started.
In .NET, awaiting `StartChildWorkflowAsync()` or `ExecuteChildWorkflowAsync()` internally waits for this Event before returning, so the Child Workflow is guaranteed to have started once the call resolves.
If you start a Child Workflow from a non-main context (for example, a Signal or Update handler), make sure the Parent Workflow doesn't complete before that call resolves.

To spawn a Child Workflow Execution in .NET, use the `ExecuteChildWorkflowAsync()` method which starts the Child Workflow and waits for completion or
use the `StartChildWorkflowAsync()` method to start a Child Workflow and return its handle.
This is useful if you want to do something after it has only started, or to get the Workflow/Run ID, or to be able to signal it while running.

> **📝 Note:**
>
> `ExecuteChildWorkflowAsync()` is a helper method for `StartChildWorkflowAsync()` plus `await handle.GetResultAsync()`.
>

```csharp
await Workflow.ExecuteChildWorkflowAsync((MyChildWorkflow wf) => wf.RunAsync());
```

## Set a Parent Close Policy 

A [Parent Close Policy](/parent-close-policy) determines what happens to a Child Workflow Execution if its Parent changes to a Closed status (Completed, Failed, or Timed Out).

The default Parent Close Policy option is set to terminate the Child Workflow Execution.

Set the `ParentClosePolicy` property inside the [`ChildWorkflowOptions`](https://dotnet.temporal.io/api/Temporalio.Workflows.ChildWorkflowOptions.html) for `ExecuteChildWorkflowAsync` or `StartChildWorkflowAsync` to specify the behavior of the Child Workflow when the Parent Workflow closes.

```csharp
await Workflow.ExecuteChildWorkflowAsync(
  (MyChildWorkflow wf) => wf.RunAsync(),
  new() { ParentClosePolicy = ParentClosePolicy.Abandon });
```