---
title: "Custom Transformation Steps"
canonical: "https://wiki.yellowfinbi.com/space/user80/1541497/Custom%20Transformation%20Steps"
format: markdown
---
This guide is for developers who want to create their own Data Transformation widgets for Yellowfin. After development, widgets may be imported into Yellowfin using the plug-in manager. Developers may write their own Input, Transformation and Output widgets.


## Setup Overview

These are the prerequisites for setting up the development environment for writing any Yellowfin plug-ins:

- Set up your preferred IDE. The steps in this guide use Eclipse for EE developers.
- Install the Tomcat plug-in for your IDE, if it’s not already included in the installation.
- Install the version of Yellowfin to be used for development.
- Start up Yellowfin to extract the WAR file.

## Javadoc

This guide links to Yellowfin's javadoc containing detailed documentation of the entire Data Transformation API. Click [here](https://developers.yellowfinbi.com/dev/data-transformation/etl-javadoc/ETL-Javadoc-v1.0/) to view the javadoc.

You can also download the latest javadoc here: 

 

## Guide Contents

The following sections are covered in this guide:

- **[Data transformation objects:](https://yellowfin.atlassian.net/wiki/spaces/user80/pages/1540292)** This section contains information on the objects involved in the data transformation process.
- **[Step implementation:](https://yellowfin.atlassian.net/wiki/spaces/user80/pages/1592683)** This explains how the step interface and processing logic should be implemented.
- **[Data transformation parameters:](https://yellowfin.atlassian.net/wiki/spaces/user80/pages/1540613)**[ ](https://yellowfin.atlassian.net/wiki/spaces/user80/pages/1540613)This provides information on how to implement parameters used when transformation data.
- **[Code examples:](https://yellowfin.atlassian.net/wiki/spaces/user80/pages/1540397)** Download code bundles, equipped with yfp files (containing dependencies) to use in your environment, or simply refer to the code.