> For the complete documentation index, see [llms.txt](https://docs.jetadmin.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.jetadmin.io/classic-app-builder/maintain-an-existing-classic-app.md).

# Classic Builder overview

Applies to **Classic App Builder**. Screens and recordings in this section show the Classic interface.

Maintain and extend an existing app built with the visual, drag-and-drop editor. Start with the page, component, or action you need to change.

![Classic builder showing a product table on the visual canvas and the component palette](https://3448227606-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LQ08RFAKZvFADEiXKFy%2Fuploads%2FRIJ2cdUu5dR1HqNd38On%2Fclassic-builder-overview.jpg?alt=media)

The Classic builder places the app canvas beside its component palette. Parameters, Actions, Overlays, and Variables are in the top toolbar.

## Maintain an existing app

1. Identify the affected page, resource, and user task.
2. Review the current component settings, bindings, and actions.
3. Make the change in an appropriate test environment using synthetic records.
4. Check expected behavior and a failure case.
5. [Test and publish](/classic-app-builder/preview-and-publish.md) using the workflow available in your Classic app.

## Find the right guide

| Task                                      | Section                                                                                              |
| ----------------------------------------- | ---------------------------------------------------------------------------------------------------- |
| Organize a page or choose a UI component  | [Pages and components](/classic-app-builder/design-and-structure.md)                                 |
| Pass selected records and other values    | [Data binding and variables](/classic-app-builder/binding-and-values.md)                             |
| Configure buttons, formulas, or workflows | [Actions and logic](/classic-app-builder/actions-and-logic.md)                                       |
| Change styling or language                | [Appearance and localization](/classic-app-builder/appearance-and-localization.md)                   |
| Design a custom component                 | [Component Designer and Figma](/classic-app-builder/component-designer.md)                           |
| Follow a complete example                 | [Practical guides](/classic-app-builder/classic-tutorials.md)                                        |
| Investigate an existing problem           | [Troubleshoot a Classic app](/classic-app-builder/preview-and-publish/troubleshoot-a-classic-app.md) |
| Learn from recordings                     | [Video tutorials](/classic-app-builder/videos.md)                                                    |
| Assess a move to a prompt-built app       | [Move to AI App Builder](/classic-app-builder/move-to-ai-app-builder.md)                             |

## Identify the builder

These guides describe components on a visual canvas, their settings, and explicit bindings. For the prompt-based workflow, use [AI App Builder](/ai-app-builder/overview.md).

The Legacy label identifies this documentation path. It is not an end-of-support date or a promise of automatic app conversion.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://docs.jetadmin.io/classic-app-builder/maintain-an-existing-classic-app.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.