# exec

The `exec` step type hands full process ownership to another command, so your workflows can launch terminal-native tools — interactive sessions, REPLs, or port-forwards — exactly as if you had run them yourself.

```yaml
steps:
  - name: session
    type: exec
    command: aws ssm start-session --target i-0123456789abcdef0
```

## Fields

- **`command`**
  Required. Command to execute.
- **`working_directory`**
  Optional directory where the command starts.
- **`env`**
  Optional environment variables for the command.

Because the process is replaced, an `exec` step must be the final step. Later workflow steps cannot run after process replacement.