Metainfo and screenshots

Your store page is built from your app’s AppStream metainfo, the standard file every Linux software center reads. Write it well once and your app looks right in Depot and in software centers on other distributions.

Install it at /app/share/metainfo/<app-id>.metainfo.xml.

What Depot shows, and where it comes from

Luma copies your icon and screenshots to dl.simplyluma.com and records each file’s SHA-256, which Depot checks. Nothing on a listing is loaded from your own server.

When the developer portal opens, its store page will also let you edit the name, summary, description, links, license and sign-in declaration.

A store-ready example

This example passes appstreamcli validate --no-net --pedantic. The only pedantic note is that the ID contains capital letters, which is normal.

<?xml version="1.0" encoding="UTF-8"?>
<component type="desktop-application">
  <id>com.example.Notebook</id>
  <metadata_license>CC0-1.0</metadata_license>
  <project_license>Apache-2.0</project_license>

  <name>Notebook</name>
  <summary>Keep short notes</summary>
  <description>
    <p>Notebook keeps short notes in one adaptive window that works on a desktop,
    a tablet and a phone.</p>
    <ul>
      <li>Create a note with one keystroke</li>
      <li>Find any note as you type</li>
      <li>Works offline; your notes stay on your device</li>
    </ul>
  </description>

  <developer id="com.example">
    <name>Example Developer</name>
  </developer>

  <launchable type="desktop-id">com.example.Notebook.desktop</launchable>
  <provides>
    <binary>com.example.Notebook</binary>
  </provides>

  <categories>
    <category>Office</category>
  </categories>
  <keywords>
    <keyword>notes</keyword>
    <keyword>memo</keyword>
  </keywords>

  <url type="homepage">https://example.com/notebook</url>
  <url type="bugtracker">https://example.com/notebook/issues</url>
  <url type="help">https://example.com/notebook/help</url>
  <url type="vcs-browser">https://example.com/notebook/source</url>
  <url type="contact">https://example.com/contact</url>

  <supports>
    <control>pointing</control>
    <control>keyboard</control>
    <control>touch</control>
  </supports>
  <requires>
    <display_length compare="ge">360</display_length>
  </requires>

  <screenshots>
    <screenshot type="default">
      <caption>Notes in the sidebar and the editor</caption>
      <image type="source" width="2560" height="1600">https://example.com/notebook/screenshots/main.png</image>
    </screenshot>
    <screenshot>
      <caption>The same app on a phone</caption>
      <image type="source" width="1080" height="2400">https://example.com/notebook/screenshots/phone.png</image>
    </screenshot>
  </screenshots>

  <custom>
    <value key="org.projectluma.ApplicationContract">0.2</value>
  </custom>

  <content_rating type="oars-1.1"/>

  <releases>
    <release version="0.2.0" date="2026-10-01">
      <description>
        <p>Search as you type, and a new phone layout.</p>
      </description>
    </release>
    <release version="0.1.0" date="2026-09-15"/>
  </releases>
</component>

Required for submission

Release submission is not open yet. When it opens, a release needs:

1. A valid file: appstreamcli validate --no-net passes with no errors.
2. <id> equal to your app ID, with a matching <launchable>.
3. <name>, a <summary> of about 35 characters or fewer that does not repeat the name, and a <description> of at least one paragraph.
4. <metadata_license> (use CC0-1.0) and an SPDX <project_license>. For a proprietary app use LicenseRef-proprietary.
5. <developer> with a <name>.
6. At least one <screenshot> with a caption.
7. A <release> for the version you are submitting, with a date and, from your second release on, a description of what changed.
8. <content_rating type="oars-1.1">, with every content attribute your app actually has declared. Generate it with the OARS questionnaire.
9. The org.projectluma.ApplicationContract custom value 0.2 if you use luma-app.toml. luma lint checks it.
10. A <url type="homepage">. If your app sends any personal data off the device, a privacy policy link in your listing too.

Screenshots

Screenshots are the most important part of your listing.

Requirements

• PNG, of your real app running, showing real functionality.
• Hosted at a stable HTTPS URL. Luma keeps its own copy, so changing the file at your URL does not change your listing; submit a release with new screenshots instead.
• At least 1280 by 800 for desktop screenshots. The Luma reference size is 2560 by 1600 (a 16:10 window at 2x).
• No device frames, marketing text overlays, prices, ratings, or other apps’ or companies’ content you do not have rights to.
• No personal data of real people. Use sample data.

Recommendations

• Lead with the screenshot that shows what the app is for.
• Capture the window alone, with its frame, on Luma’s default light appearance. Add a dark appearance screenshot if it helps.
• Include one phone-width screenshot to show your app adapts.
• Use sentence case captions of five to ten words that say what is shown.
• Keep them current: update screenshots when the interface changes.

Release notes

Write release notes for people, not for developers:

• Lead with what people will notice.
• Use short paragraphs or a list of up to about five items.
• Mention new permissions and why you need them.
• Leave out internal refactors and dependency bumps unless they fix something people saw.

Validate

appstreamcli validate --no-net data/com.example.Notebook.metainfo.xml
desktop-file-validate data/com.example.Notebook.desktop
luma lint