# Create a Custom task


> Run a reusable prompt on selected product fields and save the result to an output field.


Canonical URL: https://www.copyhero.app/help/tasks/custom-task

Use a **Custom** task when the built-in task types do not express the transformation you need.

## Before you begin [#before-you-begin]

Choose the product fields the prompt needs and the field where CopyHero should save its result. Write a prompt that explains the desired result and how to use the selected inputs.

<!-- screenshot: custom-task-form -->

## Create the task [#create-the-task]

1. Open **Tasks**, select **New Task**, then select **Custom**.
2. On **General**, enter **Name** and an optional **Description**.
3. Select the input fields to provide to the prompt, including **Extra** only when needed.
4. Select an **Output Field**.
5. Open **Prompt** and enter the instructions for CopyHero.
6. Select **Create Task**.

## Expected result [#expected-result]

The task appears in **Tasks** and can be placed in a workflow. On a run, it reads the selected fields and writes the generated result to its selected output field.

## Errors and limits [#errors-and-limits]

A name, at least one input field, an output field, and a prompt are required. Avoid choosing an output field that would overwrite information you need later in the same workflow. Keep prompts specific; vague instructions can produce inconsistent results.

## Related links [#related-links]

* [Product fields for Custom tasks](/help/tasks/product-fields)
* [Build a workflow](/help/workflows/build-workflow)
* [Workflow history and job states](/help/workflows/workflow-history-and-job-states)