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latestOpenAPI 3.0.0Apache 2.0 License2026-07-1456373564.1 KB

Starts a new task using the specified task definition.

You can allow Amazon ECS to place tasks for you, or you can customize how Amazon ECS places tasks using placement constraints and placement strategies. For more information, see Scheduling Tasks in the Amazon Elastic Container Service Developer Guide.

Alternatively, you can use StartTask to use your own scheduler or place tasks manually on specific container instances.

Starting April 15, 2023, Amazon Web Services will not onboard new customers to Amazon Elastic Inference (EI), and will help current customers migrate their workloads to options that offer better price and performance. After April 15, 2023, new customers will not be able to launch instances with Amazon EI accelerators in Amazon SageMaker, Amazon ECS, or Amazon EC2. However, customers who have used Amazon EI at least once during the past 30-day period are considered current customers and will be able to continue using the service.

The Amazon ECS API follows an eventual consistency model. This is because of the distributed nature of the system supporting the API. This means that the result of an API command you run that affects your Amazon ECS resources might not be immediately visible to all subsequent commands you run. Keep this in mind when you carry out an API command that immediately follows a previous API command.

To manage eventual consistency, you can do the following:

  • Confirm the state of the resource before you run a command to modify it. Run the DescribeTasks command using an exponential backoff algorithm to ensure that you allow enough time for the previous command to propagate through the system. To do this, run the DescribeTasks command repeatedly, starting with a couple of seconds of wait time and increasing gradually up to five minutes of wait time.

  • Add wait time between subsequent commands, even if the DescribeTasks command returns an accurate response. Apply an exponential backoff algorithm starting with a couple of seconds of wait time, and increase gradually up to about five minutes of wait time.

post/#X-Amz-Target=AmazonEC2ContainerServiceV20141113.RunTask

Headers

X-Amz-Target'AmazonEC2ContainerServiceV20141113.RunTask' required

Request body

clusterstring

The short name or full Amazon Resource Name (ARN) of the cluster to run your task on. If you do not specify a cluster, the default cluster is assumed.

countinteger

The number of instantiations of the specified task to place on your cluster. You can specify up to 10 tasks for each call.

enableECSManagedTagsboolean

Specifies whether to use Amazon ECS managed tags for the task. For more information, see <a href="https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-using-tags.html">Tagging Your Amazon ECS Resources</a> in the <i>Amazon Elastic Container Service Developer Guide</i>.

enableExecuteCommandboolean
<p>Determines whether to use the execute command functionality for the containers in this task. If <code>true</code>, this enables execute command functionality on all containers in the task.</p> <p>If <code>true</code>, then the task definition must have a task role, or you must provide one as an override.</p>
groupstring

The name of the task group to associate with the task. The default value is the family name of the task definition (for example, <code>family:my-family-name</code>).

launchType'EC2' | 'FARGATE' | 'EXTERNAL'
<p>The infrastructure to run your standalone task on. For more information, see <a href="https://docs.aws.amazon.com/AmazonECS/latest/developerguide/launch_types.html">Amazon ECS launch types</a> in the <i>Amazon Elastic Container Service Developer Guide</i>.</p> <p>The <code>FARGATE</code> launch type runs your tasks on Fargate On-Demand infrastructure.</p> <note> <p>Fargate Spot infrastructure is available for use but a capacity provider strategy must be used. For more information, see <a href="https://docs.aws.amazon.com/AmazonECS/latest/userguide/fargate-capacity-providers.html">Fargate capacity providers</a> in the <i>Amazon ECS User Guide for Fargate</i>.</p> </note> <p>The <code>EC2</code> launch type runs your tasks on Amazon EC2 instances registered to your cluster.</p> <p>The <code>EXTERNAL</code> launch type runs your tasks on your on-premises server or virtual machine (VM) capacity registered to your cluster.</p> <p>A task can use either a launch type or a capacity provider strategy. If a <code>launchType</code> is specified, the <code>capacityProviderStrategy</code> parameter must be omitted.</p> <p>When you use cluster auto scaling, you must specify <code>capacityProviderStrategy</code> and not <code>launchType</code>. </p>
platformVersionstring

The platform version the task uses. A platform version is only specified for tasks hosted on Fargate. If one isn't specified, the <code>LATEST</code> platform version is used. For more information, see <a href="https://docs.aws.amazon.com/AmazonECS/latest/developerguide/platform_versions.html">Fargate platform versions</a> in the <i>Amazon Elastic Container Service Developer Guide</i>.

propagateTags'TASK_DEFINITION' | 'SERVICE' | 'NONE'
<p>Specifies whether to propagate the tags from the task definition to the task. If no value is specified, the tags aren't propagated. Tags can only be propagated to the task during task creation. To add tags to a task after task creation, use the <a>TagResource</a> API action.</p> <note> <p>An error will be received if you specify the <code>SERVICE</code> option when running a task.</p> </note>
referenceIdstring

The reference ID to use for the task. The reference ID can have a maximum length of 1024 characters.

startedBystring
<p>An optional tag specified when a task is started. For example, if you automatically trigger a task to run a batch process job, you could apply a unique identifier for that job to your task with the <code>startedBy</code> parameter. You can then identify which tasks belong to that job by filtering the results of a <a>ListTasks</a> call with the <code>startedBy</code> value. Up to 36 letters (uppercase and lowercase), numbers, hyphens (-), and underscores (_) are allowed.</p> <p>If a task is started by an Amazon ECS service, then the <code>startedBy</code> parameter contains the deployment ID of the service that starts it.</p>
taskDefinitionstring required
<p>The <code>family</code> and <code>revision</code> (<code>family:revision</code>) or full ARN of the task definition to run. If a <code>revision</code> isn't specified, the latest <code>ACTIVE</code> revision is used.</p> <p>When you create a policy for run-task, you can set the resource to be the latest task definition revision, or a specific revision.</p> <p>The full ARN value must match the value that you specified as the <code>Resource</code> of the principal's permissions policy.</p> <p>When you specify the policy resource as the latest task definition version (by setting the <code>Resource</code> in the policy to <code>arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName</code>), then set this value to <code>arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName</code>.</p> <p>When you specify the policy resource as a specific task definition version (by setting the <code>Resource</code> in the policy to <code>arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName:1</code> or <code>arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName:*</code>), then set this value to <code>arn:aws:ecs:us-east-1:111122223333:task-definition/TaskFamilyName:1</code>.</p> <p>For more information, see <a href="https://docs.aws.amazon.com/AmazonECS/latest/developerguide/security_iam_service-with-iam.html#security_iam_service-with-iam-id-based-policies-resources">Policy Resources for Amazon ECS</a> in the Amazon Elastic Container Service developer Guide.</p>

Response

Success

Example response

{
  "tasks": [
    {
      "containerInstanceArn": "arn:aws:ecs:us-east-1:<aws_account_id>:container-instance/ffe3d344-77e2-476c-a4d0-bf560ad50acb",
      "containers": [
        {
          "name": "sleep",
          "containerArn": "arn:aws:ecs:us-east-1:<aws_account_id>:container/58591c8e-be29-4ddf-95aa-ee459d4c59fd",
          "lastStatus": "PENDING",
          "taskArn": "arn:aws:ecs:us-east-1:<aws_account_id>:task/a9f21ea7-c9f5-44b1-b8e6-b31f50ed33c0"
        }
      ],
      "desiredStatus": "RUNNING",
      "lastStatus": "PENDING",
      "overrides": {
        "containerOverrides": [
          {
            "name": "sleep"
          }
        ]
      },
      "taskArn": "arn:aws:ecs:us-east-1:<aws_account_id>:task/a9f21ea7-c9f5-44b1-b8e6-b31f50ed33c0",
      "taskDefinitionArn": "arn:aws:ecs:us-east-1:<aws_account_id>:task-definition/sleep360:1"
    }
  ]
}