# Amazon ECS task metadata endpoint version 4 for tasks on Amazon ECS Managed Instances
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**Important**  
If you are using Amazon ECS tasks hosted on Amazon EC2 instances, see [Amazon ECS task metadata endpoint](https://docs.amazonaws.cn/AmazonECS/latest/developerguide/task-metadata-endpoint.html).

Beginning with Amazon ECS Managed Instances, an environment variable named `ECS_CONTAINER_METADATA_URI_V4` is injected into each container in a task. When you query the task metadata endpoint version 4, various task metadata and [Docker stats](https://docs.docker.com/engine/api/v1.30/#operation/ContainerStats) are available to tasks.

The task metadata endpoint is on by default for all Amazon ECS tasks run on Amazon ECS Managed Instances.

**Note**  
To avoid the need to create new task metadata endpoint versions in the future, additional metadata may be added to the version 4 output. We will not remove any existing metadata or change the metadata field names.

## Amazon ECS Managed Instances task metadata endpoint version 4 paths
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The following task metadata endpoints are available to containers:

`${ECS_CONTAINER_METADATA_URI_V4}`  
This path returns metadata for the container.

`${ECS_CONTAINER_METADATA_URI_V4}/task`  
This path returns metadata for the task, including a list of the container IDs and names for all of the containers associated with the task. For more information about the response for this endpoint, see [Amazon ECS task metadata v4 JSON response for tasks on Amazon ECS Managed Instances](task-metadata-endpoint-v4-managed-instances-response.md).

`${ECS_CONTAINER_METADATA_URI_V4}/stats`  
This path returns Docker stats for the Docker container. For more information about each of the returned stats, see [ContainerStats](https://docs.docker.com/engine/api/v1.30/#operation/ContainerStats) in the Docker API documentation.  
Amazon ECS tasks on Amazon ECS Managed Instances require that the container run for \~1 second prior to returning the container stats.

`${ECS_CONTAINER_METADATA_URI_V4}/task/stats`  
This path returns Docker stats for all of the containers associated with the task. For more information about each of the returned stats, see [ContainerStats](https://docs.docker.com/engine/api/v1.30/#operation/ContainerStats) in the Docker API documentation.  
Amazon ECS tasks on Amazon ECS Managed Instances require that the container run for \~1 second prior to returning the container stats.

`${ECS_CONTAINER_METADATA_URI_V4}/tasks`  
This path returns metadata for all tasks running on the container instance. The response is a JSON array of task metadata objects, where each element has the same structure as the response from the `/task` endpoint. For more information about the response for each task, see [Amazon ECS task metadata v4 JSON response for tasks on Amazon ECS Managed Instances](task-metadata-endpoint-v4-managed-instances-response.md).  
This endpoint is only available for tasks running as a Managed Daemon Service on Amazon ECS Managed Instances.

`${ECS_CONTAINER_METADATA_URI_V4}/tasks/stats`  
This path returns Docker stats for all containers across all tasks running on the container instance. The response is a JSON array where each element contains a map of container IDs to their Docker stats for a given task. For more information about each of the returned stats, see [ContainerStats](https://docs.docker.com/engine/api/v1.30/#operation/ContainerStats) in the Docker API documentation.  
This endpoint is only available for tasks running as a Managed Daemon Service on Amazon ECS Managed Instances.