> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blobhub.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Execution

Start a new execution of a workflow definition within a session.

## **POST** `/revisions/:id/data/command` (Command: `create_execution`)

### Request Body

| Parameter       | Type   | Required | Description                                               |
| :-------------- | :----- | :------- | :-------------------------------------------------------- |
| `engine`        | string | Yes      | Must be `workflow_blobhub`.                               |
| `command`       | string | Yes      | Must be `create_execution`.                               |
| `session_id`    | string | Yes      | The ID of the session.                                    |
| `definition_id` | string | No       | ID of definition to execute (or use `alias`).             |
| `alias`         | string | No       | Alias of definition to execute (or use `definition_id`).  |
| `input_data`    | array  | No       | List of input objects `{"alias": "foo", "value": {...}}`. |

### Response

| Parameter   | Type   | Description                   |
| :---------- | :----- | :---------------------------- |
| `execution` | object | The created execution object. |

### Example

<CodeGroup>
  ```json Request theme={null}
  {
    "engine": "workflow_blobhub",
    "command": "create_execution",
    "session_id": "sess_001",
    "alias": "data-process",
    "input_data": [
      { "alias": "input_1", "value": { "type": "string" } }
    ]
  }
  ```

  ```json Response theme={null}
  {
    "execution": {
      "id": "exec_001",
      "status": "creating"
    }
  }
  ```
</CodeGroup>