> Portal Navigation:
> 
> - Append `.md` to any URL under `https://dev.wix.com/docs/` to get its markdown version.
> - Pages are either content pages (article or reference text) or menu pages (a list of links to child pages).
> - To get a menu page, truncate any URL to a parent path and append `.md` (e.g. `https://dev.wix.com/docs/sdk.md`, `https://dev.wix.com/docs/sdk/core-modules.md`).
> - If a reference page seems to be missing its schema (parameters, return types, or type definitions), append `?schema=true` to its `.md` URL (e.g. `https://dev.wix.com/docs/contexts/contexts/stores/category-info/use-category-info-context.md?schema=true`).
> - Top-level index of all portals: https://dev.wix.com/docs/llms.txt
> - Full concatenated docs: https://dev.wix.com/docs/llms-full.txt

## Resource: About Apps in Wix Harmony and Wix Studio Two

## Article: Wix Harmony and Apps

## Article Link: https://dev.wix.com/docs/build-apps/get-started/overview/about-apps-in-wix-harmony-and-wix-studio-two.md

## Article Content:

# About Apps in Wix Harmony and Wix Studio Two

Wix Harmony is Wix's AI-powered site editor. Wix Studio Two is built on the same architecture as Harmony and adds a coding environment where site developers build custom React components. Studio Two is a separate editor from Wix Studio.

Both editors use a technical architecture that's different from previous editors, so the way apps and extensions work across Wix is evolving. This overview explains app compatibility in Harmony and Studio Two, what's changing, and your options for supporting users across all Wix editors and frameworks.

> **Note:** For information about extending sites, see [About Wix Harmony](https://dev.wix.com/docs/develop-websites-sdk/get-started/overview/about-wix-harmony.md) and the [About Extending Websites with Studio Two](https://dev.wix.com/docs/studio-two/get-started/about-extending-websites-with-studio-two.md). For Blocks-specific information, see [About Wix Blocks in Wix Harmony and Wix Studio Two](https://dev.wix.com/docs/build-apps/develop-your-app/develop-an-app-with-blocks/about-wix-harmony-and-blocks.md).

## App compatibility at a glance

Apps can be installed in Harmony and Studio Two, though the UI and App Market experience differs from other editors. Due to architectural and technology updates, some app types are only available in certain editors.

The following table shows which extension types each editor supports:

| Extension type                  | Wix Harmony | Wix Studio Two | Wix Editor & Wix Studio |
| ------------------------------- | :---------: | :------------: | :---------------------: |
| Dashboard extensions            | ✓           | ✓              | ✓                       |
| Backend extensions              | ✓           | ✓              | ✓                       |
| CLI site extensions             | ✓           | ✓              | ✓                       |
| Self-managed site extensions    | ✓           | ✓              | ✓                       |
| Blocks site widgets and plugins | —           | —              | ✓                       |
| Legacy custom elements          | —           | —              | ✓                       |
| Legacy iFrame widgets and pages | Partial     | Partial        | ✓                       |
| Editor React Components         | ✓           | ✓              | —                       |

> **Note:** In Harmony and Studio Two, your app's [site plugins](https://dev.wix.com/docs/build-apps/develop-your-app/extensions/site-extensions/site-plugins/about-site-plugin-extensions.md) can fill slots only in Wix business solution widgets built with Wix's previous widget technology, where they work the same way as in Wix Editor and Wix Studio. Some Wix business solution widgets in these editors are built as Editor React Components, and apps can't currently add site plugins to these widgets. Support for adding site plugins to these widgets is planned.

## Apps and the Studio Two component model

Studio Two site developers build custom components in their site's code:

- **[Editor React Components](https://dev.wix.com/docs/overview/extensions-framework/site-extensions/editor-react-components.md) (ERCs):** React components that Wix users place on pages.
- **[Data Sources](https://dev.wix.com/docs/overview/extensions-framework/site-extensions/context-providers.md):** Logical components that share state and behavior with the components on a page. A Data Source's generated code uses context provider APIs.
- **[Function libraries](https://dev.wix.com/docs/overview/extensions-framework/site-extensions/function-libraries.md):** Collections of reusable functions that a Wix user connects to components through editor binding.

Apps can use only part of this model:

- **ERCs:** Your app can include ERCs, the same as in Harmony.
- **Data Sources from Wix business solutions:** Through editor binding, a Wix user can connect your ERC's props to Data Sources from business solutions such as Wix Stores and Wix Bookings.
- **Your app's own Data Sources:** Apps can't currently include Data Sources.
- **Exposed values and functions:** Your app's ERCs can't currently expose values or functions for other components to connect to.
- **Function libraries:** Apps can't currently include function libraries.

## What this means for existing apps

Your app's availability in Harmony and Studio Two depends on the types of extensions it includes:

- **Supported extensions:** Your app works in Harmony and Studio Two with no changes required.
- **Unsupported extensions:** Your app works on Wix Editor and Wix Studio, but can't be installed by Harmony or Studio Two users. To reach these users, rebuild unsupported extensions using the [Wix CLI for Apps](https://dev.wix.com/docs/build-apps/develop-your-app/frameworks/wix-cli/about-the-wix-cli-for-apps.md) or [self-managing](https://dev.wix.com/docs/build-apps/develop-your-app/frameworks/self-hosting/about-self-hosting.md).
- **Partial support (iFrames):** If your app uses legacy iFrame widgets or pages, test your app thoroughly in Harmony and Studio Two. If you encounter issues, [reach out to us](https://dev.wix.com/docs/build-apps/manage-your-app/contact-us/submit-support-requests.md) for help.

## Recommendations for new apps

When building a new app, use frameworks supported in Harmony and Studio Two:

- **Wix CLI:** Build app extensions using your preferred IDE, with local development, testing tools, and full control over your code. Learn more in the [Wix CLI documentation](https://dev.wix.com/docs/build-apps/develop-your-app/develop-an-app-with-the-cli/about-the-wix-cli.md).
- **Self-managed:** Use your own infrastructure for backend, site, or dashboard extensions. Learn more about [self-managed extensions](https://dev.wix.com/docs/build-apps/develop-your-app/develop-a-self-managed-app/supported-extensions/about-self-managed-app-extensions.md).

## Test your app

We recommend testing your app in Harmony and Studio Two to ensure it works as expected. Create a [development site](https://dev.wix.com/docs/build-apps/develop-your-app/development-sites/about-development-sites.md) in each editor to test your app's functionality and user experience.

To learn more, see [Test Your App on a Free Premium Site](https://dev.wix.com/docs/build-apps/launch-your-app/app-distribution/test-your-app/test-your-app-on-a-premium-site.md).

## FAQ

### Migration and compatibility

<details>
<summary>Can Blocks apps be migrated to the CLI or site widgets?</summary>

Currently, there is no automatic migration path to convert Blocks apps directly to the new CLI or site widget tools. To move to the new architecture, you need to build a new extension.

We've created a [step-by-step guide](https://dev.wix.com/docs/build-apps/develop-your-app/extensions/site-extensions/migrate-to-a-new-site-widget-or-plugin-extension.md) on how to rebuild and update your app using the new tools. We're also exploring solutions to streamline this process in the future.

</details>

<details>
<summary>What happens to existing Blocks apps when customers move from Classic/Studio to Harmony?</summary>

Currently, there is no migration tool from Classic/Studio to Wix Harmony.

</details>

<details>
<summary>Is there a way to move existing users from a Blocks app to a new implementation without losing reviews or installs, or without supporting 2 app versions?</summary>

You can maintain your existing reviews and install base by adding your new implementation as an additional extension within your existing app, rather than creating a new app. We will be releasing a guide to assist you in migrating your active users from the old extension to the new one.

</details>

### Business impact and App Market visibility

<details>
<summary>Why are Blocks apps not discoverable or installable for Harmony and Studio Two users?</summary>

Wix Harmony and Wix Studio Two are built on a completely new technology that doesn't support Blocks apps, which means they aren't available for installation.

</details>

<details>
<summary>How can developers quickly mitigate lost customer acquisition and revenue due to Harmony and Studio Two not supporting Blocks apps?</summary>

To make your app compatible with Harmony and Studio Two, rebuild its site widgets as either of these:

- **[Custom elements](https://dev.wix.com/docs/overview/extensions-framework/site-extensions/site-widgets.md):** Work in all Wix editors, including Harmony and Studio Two. Build them with the [Wix CLI](https://dev.wix.com/docs/build-apps/develop-your-app/develop-an-app-with-the-cli/about-the-wix-cli.md) or by [self-managing](https://dev.wix.com/docs/build-apps/develop-your-app/develop-a-self-managed-app/about-self-managed-apps.md).
- **[Editor React Components](https://dev.wix.com/docs/overview/extensions-framework/site-extensions/editor-react-components.md):** Work only in Harmony and Studio Two. The editor generates their settings panels from the component's manifest. Build them with the Wix CLI.

We encourage you to adopt one of these approaches now to regain access to Harmony and Studio Two users.

</details>

<details>
<summary>What immediate options exist so current and new users can still access these apps?</summary>

Wix Editor and Wix Studio users still have full access to your apps. If you need to support Harmony and Studio Two sites now, you can start building [self-managed](https://dev.wix.com/docs/build-apps/develop-your-app/develop-a-self-managed-app/about-self-managed-apps.md) or [CLI](https://dev.wix.com/docs/build-apps/develop-your-app/develop-an-app-with-the-cli/about-the-wix-cli.md) site widgets.

</details>

### Long-term strategy and timelines

<details>
<summary>What are the timelines for deprecations and continued support for the Classic and Studio editors?</summary>

We aren't breaking any existing capabilities. If at any time we move forward with deprecation, we will make sure there is a clear and concrete plan that addresses all questions and concerns.

</details>

## Get support

If you encounter issues or have questions, feel free to [reach out to us](https://dev.wix.com/docs/build-apps/manage-your-app/contact-us/submit-support-requests.md) or ask in our [Discord community](https://discord.gg/wixstudio).

## See also

- [About Wix Blocks in Wix Harmony and Wix Studio Two](https://dev.wix.com/docs/build-apps/develop-your-app/develop-an-app-with-blocks/about-wix-harmony-and-blocks.md)
- [About Wix Harmony](https://dev.wix.com/docs/develop-websites-sdk/get-started/overview/about-wix-harmony.md)
- [About Studio Two Extensions](https://dev.wix.com/docs/studio-two/get-started/about-studio-two-extensions.md)
- [About Extensions](https://dev.wix.com/docs/build-apps/develop-your-app/extensions/about-extensions.md)
- [About Development Frameworks](https://dev.wix.com/docs/build-apps/get-started/overview/wix-s-development-frameworks.md)