We have a few requirements and suggestions for publishing your app to AppCenter. For a quick intro on writing apps for elementary OS, check out our Getting Started guide. For more developer-oriented tips, see the Tips series on Medium.

The following are hard requirements for all apps submitted to AppCenter. Both automated and human reviews will check these requirements before each app and app update is approved and released to users.

Your app must be hosted in a GitHub repository. AppCenter Dashboard works by importing source code from a GitHub repository and building it in a clean environment. To ensure reproducible builds, transparency, and auditability, binaries cannot be uploaded or included alongside the source code to be installed on users' devices.

Your app must not attempt to modify, replace, or append software sources on the target system.

Your app must not attempt to modify other apps or system programs. Your app should not rely on other apps' GSettings, as these are considered internal/private API for those apps.

Your app may be written in any language, but the front-end must be a native GTK3 app. Web, Electron, Qt, Java, and other non-native app front-ends will be rejected during the review process.

A game may be excepted from this requirement so long as it uses native window decorations and is generally usable on both loDPI and HiDPI displays.

While apps can have web components using a native WebView, such apps must add substantial functionality to the web content, or the majority of the interface that a user interacts with must be native GTK3. Apps that primarily wrap an existing website or websites will likely be rejected.

Your app must come with Debian packaging. elementary OS uses Debian packages to manage software installation and updates. Your app cannot be downloaded without it. Your Debian packaging must not manually modify filesystem permissions.

AppCenter Dashboard and Houston CI use git branches to determine which version(s) of elementary OS to build for. When the packaging is included in the master or there is just a deb-packaging branch, a package is only built for the latest elementary OS version (currently Juno).

To target a specific elementary OS version, use a deb-packaging-[version] branch. I.e. to target elementary OS Loki, you'll need a branch named deb-packaging-loki. These branches are checked when a new version is submitted to the AppCenter or when Houston CI runs.

AppCenter supports publishing apps that meet these requirements; extensions or plugins (eg. to the Panel, System Settings, or other apps) are not currently supported.

Your app must install an appdata.xml file to /usr/share/metainfo. AppCenter uses this metadata to create a listing for your app. It cannot be displayed in AppCenter without it.

Your appdata.xml file must contain a screenshot tag that references a screenshot of your app with elementary OS default settings including the GTK stylesheet, icons, window button position, etc. Screenshots should include the app window itself—including any window borders and shadows—on a transparent background. Screenshots generally should not include the desktop (panel, dock), a wallpaper, or other backgrounds.

Your appdata.xml file must contain a developer_name tag that references your name or the name of your organization.

Your appdata.xml must include accurate Open Age Rating Service (OARS) data. OARS uses a simple, self-reported survey that only takes a few moments to output the required XML. Reviewers will check this data for accuracy in order for your app to be published.

For more information about the appdata.xml format see, see the appstream specification.

Your app must install a .desktop file to /usr/share/applications. elementary OS uses a .desktop file to display your app in the applications launcher and the dock. Without this file, your app will not be visible to users.

Your .desktop file must not contain NoDisplay=true or anything else that prevents it from showing up in the applications launcher.

Your app must install icons to /usr/share/icons/hicolor in 32px, 48px, 64px, and 128px. These are the icon sizes that will be displayed in the Applications menu's search, grid, and category views, Multitasking View, the dock, and in AppCenter.

Icons should be unique to your app; do not use copies of system icons—though a substantial deviation based on a system icon is acceptable. Icons should also not be confusingly similar to other AppCenter app icons.

You must have permission to redistribute any software you attempt to publish through AppCenter. If you are not the copyright holder or the source code is not openly licensed, you likely do not have permission to redistribute the software.

You must have permission to use any trademarks in your software or its metadata. You may not publish your app using trademarks reserved by others.

Your app must comply with all applicable laws as well as the terms of any services your app utilizes.

To protect both users and developers, your app's name must not be the same as or confusingly similar to an existing app in AppCenter or other brand, as determined by app reviewers.

Your app should not be named generically like "Web Browser" or "File Manager".

Your app should not use "elementary", "Pantheon", or other elementary brand names in its naming scheme. It should also not be formatted with a leading lowercase "e", such as "eApp".

Your app cannot be an "app store," as ultimately determined by app reviewers. This includes but is not limited to apps that look and function confusingly similarly to AppCenter, provide software from other sources, link to an online app store, and/or facilitate payments for apps in the system repositories.

For the best experience, we strongly suggest the following before you publish your app:

Once your app is submitted you cannot change the GitHub account that it is linked to. We recommend you use a GitHub organization as the owner of the repository so it can be transferred in the future if you so choose. This also makes it easier to manage community contributions. Note that anyone with access to the GitHub organization will be able to manage releases and monetization.

If you are having trouble getting your organization-owned app to show up in the AppCenter Dashboard:

1. Make sure you allow AppCenter access to your organization
2. Log out of the AppCenter Dashboard
3. Log back into the AppCenter Dashboard

While AppCenter Dashboard supports repositories with dashes and underscores, it vastly simplifies things to omit them from your GitHub repository name and subsequently your app ID. Some components in the desktop require workarounds for ID matching with dashes and underscores, so it is typically simpler to stick to all lowercase with no dashes or underscores.

Apps should generally abide by the elementary Human Interface Guidelines, especially with regards to Desktop Integration. Guidelines around System Indicators and Notifications may be strictly enforced, as it is important that apps behave as expected by users.

If your game UI properly scales when the window is resized, one easy way to support both HiDPI and loDPI (even if the engine doesn't out of the box) is simply to launch your game maximized. That way the UI will scale up no matter the resolution or scaling factor of the display.