# Mock Data
Users can now manually override DataHub variables using mock JSON data, directly from the DataHub. This ability allows configuring and testing step responses even before a workflow is synced, specifically within Code Runner and Formatter steps.
#### How It Works
* Locate a Code Runner or Formatter step in the DataHub.
* Click the mock data icon next to the step response.
* A popup will appear allowing you to edit and input mock JSON data.
* The provided mock data will:
* override the existing response for that step.
* be used as the response for downstream mapping or logic.
* be replaced automatically when the workflow is synced and a realtime response is generated.
#### Use Case
This is particularly useful for:
* Testing workflows before real data is available
* Manually configuring mappings when building new flows
* Debugging formatters or custom logic using controlled input
#### Example
Mock JSON data:
```json
{
"orderId": "12345",
"status": "PENDING",
"customer": {
"id": "9876",
"email": "test@example.com"
}
}
```
This input will be treated as the step response for downstream mapping or transformation logic.
