Short answer: Yes—do it in your ECS work pool’s base job template, not via

prefect worker start

flags. Prefect’s ECS worker forwards the

task_run_request

section of the work pool’s base job template directly to AWS ECS’s RunTask API. You can enable ECS Exec by adding

enableExecuteCommand: true

there. Steps: 1) Export the default ECS base job template

prefect work-pool get-default-base-job-template --type ecs --file ecs-template.json

2) Edit ecs-template.json and add the flag under job_configuration.task_run_request

{
  "job_configuration": {
    ...
    "task_run_request": {
      "launchType": "{{ launch_type }}",
      "cluster": "{{ cluster }}",
      "overrides": { ... },
      "tags": "{{ labels }}",
      "taskDefinition": "{{ task_definition_arn }}",
      "capacityProviderStrategy": "{{ capacity_provider_strategy }}",
      "enableExecuteCommand": true
    },
    ...
  },
  "variables": { ... }
}

3) Update your work pool with the modified template

prefect work-pool update "my-ecs-pool" --base-job-template ecs-template.json

Notes: - There isn’t a

prefect worker start

flag for this; the base job template is the right place to set ECS API options. - Make sure your IAM setup meets ECS Exec requirements (permissions for the user running

aws ecs execute-command

as well as the task/execution roles for SSM, Logs, and optional KMS). See AWS docs: Using Amazon ECS Exec and the RunTask param reference (see

enableExecuteCommand

): RunTask API. Optional (make it configurable via variables): - Add a variable to the template’s

variables

schema (e.g.,

enable_execute_command

) and reference it in the template:

"task_run_request": {
  ...,
  "enableExecuteCommand": "{{ enable_execute_command }}"
}

Then you can toggle it from the UI or via job variables. Prefect docs for ECS work pools: Prefect 3.x ECS guide