# Using Workflow to Prepare Source Tables

Workflow can be used to prepare source tables for Master Segments.

You can start the creation of a master segment by pre-processing data using workflows.

Here’s an example workflow task using an HTTP operator to start the creation of a master segment.


```yaml
+kick_audience_workflow:
  http>: "https://api-cdp.treasuredata.com/audiences/YOUR_AUDIENCE_ID/run"
  method: POST
  headers:
    - authorization: "TD1 ${secret:td.apikey}"
  retry: true
```

![](/assets/screen_shot_2019-08-23_at_10.59.43_am.d04cc83280200f65fada79bf795730cc7abb62a486da0c00d2f11afa7659f90f.142841d8.png)