There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.
# Use `ListTasks` with an AWS SDK or CLI
The following code examples show how to use `ListTasks`.
Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples:
+ [Configure container service connectivity](ecs_example_ecs_ServiceConnect_085_section.md)
+ [Create a container task for the serverless launch type](ecs_example_ecs_GettingStarted_086_section.md)
+ [Creating a container service for virtual machine instances](ecs_example_ecs_GettingStarted_018_section.md)
+ [Get ARN information for clusters, services, and tasks](ecs_example_ecs_Scenario_GetClustersServicesAndTasks_section.md)
+ [Learn Amazon ECS basics](ecs_example_ecs_Scenario_section.md)
------
#### [ .NET ]
**SDK for .NET**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/ECS#code-examples).
```
///
/// List task ARNs available.
///
/// The arn of the ECS cluster.
/// The ARN list of tasks in given cluster.
public async Task> GetTaskARNsAsync(string clusterARN)
{
// Set up the request to describe the tasks in the service
var listTasksRequest = new ListTasksRequest
{
Cluster = clusterARN
};
List taskArns = new List();
// Call the ListTasks API operation and get the list of task ARNs
var tasks = _ecsClient.Paginators.ListTasks(listTasksRequest);
await foreach (var task in tasks.TaskArns)
{
if (task is null)
continue;
taskArns.Add(task);
}
if (taskArns.Count == 0)
{
_logger.LogWarning("No tasks found in cluster: " + clusterARN);
}
return taskArns;
}
```
+ For API details, see [ListTasks](https://docs.aws.amazon.com/goto/DotNetSDKV3/ecs-2014-11-13/ListTasks) in *AWS SDK for .NET API Reference*.
------
#### [ CLI ]
**AWS CLI**
**Example 1: To list the tasks in a cluster**
The following `list-tasks` example lists all of the tasks in a cluster.
```
aws ecs list-tasks --cluster {{default}}
```
Output:
```
{
"taskArns": [
"arn:aws:ecs:us-west-2:123456789012:task/a1b2c3d4-5678-90ab-cdef-11111EXAMPLE",
"arn:aws:ecs:us-west-2:123456789012:task/a1b2c3d4-5678-90ab-cdef-22222EXAMPLE"
]
}
```
**Example 2: To list the tasks on a particular container instance**
The following `list-tasks` example lists the tasks on a container instance, using the container instance UUID as a filter.
```
aws ecs list-tasks --cluster {{default}} --container-instance {{a1b2c3d4-5678-90ab-cdef-33333EXAMPLE}}
```
Output:
```
{
"taskArns": [
"arn:aws:ecs:us-west-2:123456789012:task/a1b2c3d4-5678-90ab-cdef-44444EXAMPLE"
]
}
```
For more information, see [Amazon ECS Task Definitions](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definitions.html) in the *Amazon ECS Developer Guide*.
+ For API details, see [ListTasks](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/ecs/list-tasks.html) in *AWS CLI Command Reference*.
------
#### [ Python ]
**SDK for Python (Boto3)**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/ecs#code-examples).
```
class EcsWrapper:
"""Encapsulates Amazon ECS operations."""
def __init__(self, ecs_client: BaseClient):
"""
Initializes the EcsWrapper with an ECS client.
:param ecs_client: A Boto3 Amazon ECS client. Boto3 clients are created
by the ``boto3.client`` factory function and are instances of
``botocore.client.BaseClient``, which is the correct type to
annotate here (``boto3.client`` itself is a function, not a type).
"""
self.ecs_client = ecs_client
@classmethod
def from_client(cls) -> "EcsWrapper":
"""Creates an EcsWrapper using a default Boto3 ECS client."""
ecs_client = boto3.client("ecs")
return cls(ecs_client)
def list_tasks(
self,
cluster: str,
service_name: Optional[str] = None,
) -> List[str]:
"""
Lists task ARNs for a cluster, optionally filtered by service.
Uses paginator to handle large result sets.
:param cluster: The cluster name or ARN.
:param service_name: The service name to filter by (optional).
:return: A list of task ARN strings.
:raises ClientError: If the request fails (e.g., InvalidParameterException).
"""
try:
task_arns = list()
paginator = self.ecs_client.get_paginator("list_tasks")
params = dict()
params["cluster"] = cluster
if service_name is not None:
params["serviceName"] = service_name
for page in paginator.paginate(**params):
task_arns.extend(page.get("taskArns", list()))
logger.info(
"Listed %d tasks for cluster '%s'%s",
len(task_arns),
cluster,
f" (service='{service_name}')" if service_name else "",
)
return task_arns
except ClientError as err:
if err.response["Error"]["Code"] == "InvalidParameterException":
logger.error(
"Invalid parameter when listing tasks: %s",
err.response["Error"]["Message"],
)
raise
```
+ For API details, see [ListTasks](https://docs.aws.amazon.com/goto/boto3/ecs-2014-11-13/ListTasks) in *AWS SDK for Python (Boto3) API Reference*.
------