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

# ToDo

> Create a placeholder gem in your pipeline

export const gemName_0 = "ToDo"

The ToDo gem lets you create a placeholder in your pipeline for a future gem.

<Info>
  Prophecy may insert ToDo gems automatically during migration from another tool when certain logic
  can't be translated. [Reach out](mailto:support@prophecy.io) to learn more about migration.
</Info>

<Tip>
  The {gemName_0} gem has a corresponding interactive gem example. See [Interactive gem
  examples](/data-analysis/gems/gems#interactive-gem-examples) to learn how to run sample pipelines
  for this and other gems.
</Tip>

## Prerequisites

* Add `prophecy_basics` package version 1.0.0 or higher to your project.

## Input and Output

Though the ToDo gem does not pass any data, you can pre-configure the output schema of the gem for future reference.

| Port    | Description                                                                     |
| ------- | ------------------------------------------------------------------------------- |
| **in0** | The intended input for a future gem.                                            |
| **out** | The intended output for a future gem, for which you can create a custom schema. |

## Parameters

| Parameter         | Description                                                                                                                                       |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| Highlight message | A custom message you write. It appears in [Diagnostics](/data-analysis/development/studio/studio#footer) to describe why this placeholder exists. |
| Error message     | A system-generated message added during migration. It explains why a process couldn't be migrated so you have context for resolving it.           |
| Helper code/text  | Notes, code snippets, or context you provide to guide the development of a functional gem later on.                                               |